TOP243YN [POWERINT]
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher;
| 型号： | TOP243YN |
| 厂家： | 
Power Integrations |
| 描述： | TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher |
| 文件： | 总52页 (文件大小：2174K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
TOP242-250
®
TOPSwitch-GX Family
Extended Power, Design Flexible,
®
EcoSmart, IntegratedOff-line Switcher
Product Highlights
+
AC
IN
DC
OUT
Lower System Cost, High Design Flexibility
-
•
•
•
•
•
•
•
•
•
•
Extended power range for higher power applications
No heatsink required up to 34 W using P package
Features eliminate or reduce cost of external components
Fully integrated soft-start for minimum stress/overshoot
Externally programmable accurate current limit
Wider duty cycle for more power, smaller input capacitor
Separate line sense and current limit pins on Y/R/F packages
Line under-voltage (UV) detection: no turn off glitches
Line overvoltage (OV) shutdown extends line surge limit
D
S
L
CONTROL
C
TOPSwitch-GX
X
F
PI-2632-060200
Line feed-forward with maximum duty cycle (DCMAX
)
Figure 1. Typical Flyback Application.
reduction rejects line ripple and limits DCMAX at high line
Frequency jittering reduces EMI and EMI filtering costs
Regulates to zero load without dummy loading
132 kHz frequency reduces transformer/power supply size
Half frequency option inY/R/F packages for video applications
Hysteretic thermal shutdown for automatic fault recovery
Large thermal hysteresis prevents PC board overheating
•
•
•
•
•
•
OUTPUT POWER TABLE
230 VAC ±15%4
85-265 VAC
PRODUCT3
Open
Adapter1
Open
Adapter1
Frame2
Frame2
TOP242 P or G 9 W
TOP242 R 15 W
TOP242 Y or F 10 W
TOP242 P or G 13 W
15 W
22 W
22 W
25 W
45 W
45 W
28 W
50 W
65 W
30 W
57 W
85 W
34 W
64 W
125 W
70 W
165 W
75 W
6.5 W
11 W
7 W
10 W
14 W
14 W
15 W
23 W
30 W
20 W
28 W
45 W
22 W
33 W
60 W
26 W
38 W
90 W
43 W
125 W
48 W
155 W
53 W
180 W
55 W
210 W
EcoSmart - Energy Efficient
•
Extremely low consumption in remote off mode
(80 mW at 110 VAC, 160 mW at 230 VAC)
9 W
•
•
Frequency lowered with load for high standby efficiency
Allows shutdown/wake-up via LAN/input port
TOP243 R
29 W
17 W
15 W
11 W
20 W
20 W
13 W
23 W
26 W
15 W
26 W
40 W
28 W
55 W
30 W
70 W
31 W
80 W
32 W
90 W
TOP243 Y or F 20 W
TOP244 P or G 16 W
TOP244 R
34 W
Description
TOP244 Y or F 30 W
TOPSwitch-GX uses the same proven topology as TOPSwitch,
cost effectively integrating the high voltage power MOSFET,
PWM control, fault protection and other control circuitry onto
a single CMOS chip. Many new functions are integrated to
reducesystemcostandimprovedesignflexibility,performance
and energy efficiency.
TOP245 P
TOP245 R
19 W
37 W
TOP245 Y or F 40 W
TOP246 P
TOP246 R
21 W
40 W
TOP246 Y or F 60 W
TOP247 R 42 W
TOP247 Y or F 85 W
TOP248 R 43 W
TOP248 Y or F 105 W 205 W
TOP249 R 44 W 79 W
TOP249 Y or F 120 W 250 W
TOP250 R 45 W 82 W
TOP250 Y or F 135 W 290 W
Depending on package type, either 1 or 3 additional pins over
the TOPSwitch standard DRAIN, SOURCE and CONTROL
terminals allow the following functions: line sensing (OV/UV,
line feed-forward/DCMAX reduction), accurate externally set
current limit, remote ON/OFF, synchronization to an external
lower frequency, and frequency selection (132 kHz/66 kHz).
All package types provide the following transparent features:
Soft-start,132kHzswitchingfrequency(automaticallyreduced
Table 1. Notes: 1.Typical continuous power in a non-ventilated enclosed
adapter measured at 50 °C ambient. 2. Maximum practical continuous
power in an open frame design at 50 °C ambient. See KeyApplications
for detailed conditions. 3. For lead-free package options, see Part
Ordering Information. 4. 230 VAC or 100/115 VAC with doubler.
at light load), frequency jittering for lower EMI, wider DCMAX
,
hysteretic thermal shutdown, and larger creepage packages. In
addition, all critical parameters (i.e. current limit, frequency,
PWM gain) have tighter temperature and absolute tolerances
to simplify design and optimize system cost.
December 2004
TOP242-250
Section List
Functional Block Diagram ....................................................................................................................................... 3
Pin Functional Description ...................................................................................................................................... 4
TOPSwitch-GX Family Functional Description ....................................................................................................... 5
CONTROL (C) Pin Operation.................................................................................................................................. 6
Oscillator and Switching Frequency........................................................................................................................ 6
Pulse Width Modulator and Maximum Duty Cycle.................................................................................................. 7
Light Load Frequency Reduction............................................................................................................................ 7
Error Amplifier ......................................................................................................................................................... 7
On-Chip Current Limit with External Programmability ............................................................................................ 7
Line Under-Voltage Detection (UV)......................................................................................................................... 8
Line Overvoltage Shutdown (OV) ........................................................................................................................... 8
Line Feed-Forward with DCMAX Reduction .............................................................................................................. 8
Remote ON/OFF and Synchronization ................................................................................................................... 9
Soft-Start................................................................................................................................................................. 9
Shutdown/Auto-Restart........................................................................................................................................... 9
Hysteretic Over-Temperature Protection................................................................................................................. 9
Bandgap Reference.............................................................................................................................................. 10
High-Voltage Bias Current Source........................................................................................................................ 10
Using Feature Pins ................................................................................................................................................... 10
FREQUENCY (F) Pin Operation........................................................................................................................... 10
LINE-SENSE (L) Pin Operation ............................................................................................................................ 10
EXTERNAL CURRENT LIMIT (X) Pin Operation.................................................................................................. 11
MULTI-FUNCTION (M) Pin Operation .................................................................................................................. 11
Typical Uses of FREQUENCY (F) Pin ...................................................................................................................... 14
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins ...................................................... 15
Typical Uses of MULTI-FUNCTION (M) Pin ........................................................................................................... 17
Application Examples .............................................................................................................................................. 20
A High Efficiency, 30 W, Universal Input Power Supply........................................................................................ 20
A High Efficiency, Enclosed, 70 W, Universal Adapter Supply.............................................................................. 20
A High Efficiency, 250 W, 250-380 VDC Input Power Supply............................................................................... 22
Multiple Output, 60 W, 185-265 VAC Input Power Supply.................................................................................... 23
Processor Controlled Supply Turn On/Off............................................................................................................. 24
Key Application Considerations ............................................................................................................................. 26
TOPSwitch-II vs. TOPSwitch-GX.......................................................................................................................... 26
TOPSwitch-FX vs. TOPSwitch-GX ....................................................................................................................... 28
TOPSwitch-GX Design Considerations ............................................................................................................... 28
TOPSwitch-GX Layout Considerations................................................................................................................. 30
Quick Design Checklist......................................................................................................................................... 32
Design Tools ......................................................................................................................................................... 32
Product Specifications and Test Conditions ......................................................................................................... 33
Typical Performance Characteristics .................................................................................................................... 40
Part Ordering Information ....................................................................................................................................... 46
Package Outlines ..................................................................................................................................................... 47
M
2
12/04
TOP242-250
V
C
0
1
DRAIN (D)
CONTROL (C)
Z
C
INTERNAL
SUPPLY
SHUNT REGULATOR/
ERROR AMPLIFIER
+
-
SOFT START
5.8 V
4.8 V
-
5.8 V
+
INTERNAL UV
COMPARATOR
I
FB
V
I (LIMIT)
CURRENT
LIMIT
ADJUST
SOFT
START
-
÷ 8
ON/OFF
+
V
+ V
T
BG
SHUTDOWN/
AUTO-RESTART
CURRENT LIMIT
COMPARATOR
EXTERNAL
CURRENT LIMIT (X)
HYSTERETIC
THERMAL
STOP LOGIC
SHUTDOWN
1 V
LINE-SENSE (L)
CONTROLLED
TURN-ON
V
BG
GATE DRIVER
STOP SOFT-
OV/UV
START
D
LINE
SENSE
MAX
DC
DC
MAX
MAX
CLOCK
SAW
S
R
Q
HALF
FREQ.
-
LEADING
EDGE
BLANKING
FREQUENCY (F)
+
OSCILLATOR WITH JITTER
PWM
COMPARATOR
LIGHT LOAD
FREQUENCY
REDUCTION
R
E
SOURCE (S)
PI-2639-060600
Figure 2a. Functional Block Diagram (Y, R or F Package).
V
C
0
CONTROL (C)
DRAIN (D)
Z
C
INTERNAL
SUPPLY
1
SHUNT REGULATOR/
ERROR AMPLIFIER
+
SOFT START
5.8 V
4.8 V
-
-
5.8 V
+
INTERNAL UV
COMPARATOR
I
FB
V
I (LIMIT)
CURRENT
LIMIT
ADJUST
SOFT
START
-
÷ 8
ON/OFF
+
SHUTDOWN/
AUTO-RESTART
CURRENT LIMIT
COMPARATOR
V
+ V
T
BG
V
STOP LOGIC
HYSTERETIC
THERMAL
SHUTDOWN
MULTI-
FUNCTION (M)
CONTROLLED
TURN-ON
BG
GATE DRIVER
STOP SOFT-
OV/UV
DC
START
D
LINE
SENSE
MAX
DC
MAX
MAX
CLOCK
SAW
S
R
Q
-
LEADING
EDGE
BLANKING
+
OSCILLATOR WITH JITTER
PWM
COMPARATOR
LIGHT LOAD
FREQUENCY
REDUCTION
R
E
SOURCE (S)
PI-2641-061200
Figure 2b. Functional Block Diagram (P or G Package).
M
12/04
3
TOP242-250
FREQUENCY (F) Pin: (Y, R or F package only)
Pin Functional Description
Input pin for selecting switching frequency: 132 kHz if
connected to SOURCE pin and 66 kHz if connected to
CONTROL pin. The switching frequency is internally set for
fixed 132 kHz operation in P and G packages.
DRAIN (D) Pin:
High voltage power MOSFET drain output. The internal
start-up bias current is drawn from this pin through a switched
high-voltage current source. Internal current limit sense point
for drain current.
SOURCE (S) Pin:
Output MOSFET source connection for high voltage power
return. Primary side control circuit common and reference point.
CONTROL (C) Pin:
Error amplifier and feedback current input pin for duty cycle
control. Internal shunt regulator connection to provide internal
bias current during normal operation. It is also used as the
connection point for the supply bypass and auto-restart/
compensation capacitor.
VUV = IUV x RLS
VOV = IOV x RLS
+
For RLS = 2 MΩ
2 MΩ
RLS
VUV = 100 VDC
VOV = 450 VDC
LINE-SENSE (L) Pin: (Y, R or F package only)
Input pin for OV, UV, line feed forward with DCMAX reduction,
remoteON/OFFandsynchronization. AconnectiontoSOURCE
pin disables all functions on this pin.
DC
Input
Voltage
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
D
S
L
CONTROL
C
For RIL = 12 kΩ
ILIMIT = 69%
X
EXTERNALCURRENTLIMIT(X)Pin:(Y,RorFpackage
only)
Input pin for external current limit adjustment, remote
ON/OFF, and synchronization. A connection to SOURCE pin
disables all functions on this pin.
See Figure 54b for
other resistor values
(RIL) to select different
ILIMIT values
RIL
12 kΩ
-
Figure 4. Y/R/F Pkg Line Sense and Externally Set Current Limit.
MULTI-FUNCTION (M) Pin: (P or G package only)
This pin combines the functions of the LINE-SENSE (L) and
EXTERNAL CURRENT LIMIT (X) pins of the Y package
into one pin. Input pin for OV, UV, line feed forward with
DCMAX reduction, external current limit adjustment, remote
ON/OFF and synchronization. A connection to SOURCE pin
disables all functions on this pin and makes TOPSwitch-GX
operate in simple three terminal mode (like TOPSwitch-II).
+
VUV = IUV x RLS
VOV = IOV x RLS
For RLS = 2 MΩ
VUV = 100 VDC
VOV = 450 VDC
RLS
2 MΩ
DC
Input
Voltage
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
D
S
M
CONTROL
C
Y Package (TO-220-7C)
-
Tab Internally
Connected to
SOURCE Pin
7 D
PI-2509-040501
5 F
4 S
3 X
2 L
1 C
Figure 5. P/G Package Line Sense.
+
R Package (TO-263-7C)
F Package (TO-262-7C)
For RIL = 12 kΩ
ILIMIT = 69%
P Package (DIP-8B)
G Package (SMD-8B)
For RIL = 25 kΩ
ILIMIT = 43%
DC
Input
Voltage
M
S
S
S
1
2
8
7
See Figures 54b, 55b
and 56b for other resistor
values (RIL) to select
different ILIMIT values.
D
S
M
S
C
3
4
CONTROL
C
RIL
5
D
1 2 3 4 5
7
C L X S F D PI-2724-010802
-
PI-2517-022604
Figure 3. Pin Configuration (top view).
Figure 6. P/G Package Externally Set Current Limit.
M
4
12/04
TOP242-250
TOPSwitch-GX Family Functional
Description
Auto-restart
ICD1
IB
I
= 125 µA
L
Like TOPSwitch, TOPSwitch-GX is an integrated switched
mode power supply chip that converts a current at the control
input to a duty cycle at the open drain output of a high voltage
power MOSFET. During normal operation the duty cycle
of the power MOSFET decreases linearly with increasing
CONTROL pin current as shown in Figure 7.
132
I
< I
L(DC)
L
I
= 190 µA
L
30
In addition to the three terminal TOPSwitch features, such as
the high voltage start-up, the cycle-by-cycle current limiting,
loop compensation circuitry, auto-restart, thermal shutdown,
theTOPSwitch-GXincorporatesmanyadditionalfunctionsthat
reduce system cost, increase power supply performance and
design flexibility. A patented high voltage CMOS technology
allows both the high voltage power MOSFET and all the low
voltage control circuitry to be cost effectively integrated onto
a single monolithic chip.
IC (mA)
Auto-restart
ICD1
IB
78
Slope = PWM Gain
Three terminals, FREQUENCY, LINE-SENSE, and
EXTERNAL CURRENT LIMIT (available in Y, R or F
package) or one terminal MULTI-FUNCTION (available in P
or G package) have been added to implement some of the new
functions. These terminals can be connected to the SOURCE
pin to operate the TOPSwitch-GX in a TOPSwitch-like three
terminal mode. However, even in this three terminal mode, the
TOPSwitch-GX offers many new transparent features that do
not require any external components:
I
= 125 µA
L
38
10
I
< I
L(DC)
L
I
= 190 µA
L
TOP242-5 1.6 2.0
TOP246-9 2.2 2.6
TOP250 2.4 2.7
5.2 6.0
5.8 6.6
6.5 7.3
IC (mA)
Note: For P and G packages IL is replaced with IM.
1. A fully integrated 10 ms soft-start limits peak currents
and voltages during start-up and dramatically reduces or
eliminates output overshoot in most applications.
2. DCMAX of78%allowssmallerinputstoragecapacitor, lower
input voltage requirement and/or higher power capability.
3. Frequency reduction at light loads lowers the switching
lossesandmaintainsgoodcrossregulationinmultipleoutput
supplies.
PI-2633-011502
Figure 7. Relationship of Duty Cycle and Frequency to CONTROL
Pin Current.
The pin can also be used as a remote ON/OFF and a
synchronization input.
4. Higher switching frequency of 132 kHz reduces the
transformer size with no noticeable impact on EMI.
5. Frequency jittering reduces EMI.
6. Hysteretic over-temperature shutdown ensures automatic
recovery from thermal fault. Large hysteresis prevents
circuit board overheating.
The EXTERNAL CURRENT LIMIT (X) pin is usually used
to reduce the current limit externally to a value close to the
operating peak current, by connecting the pin to SOURCE
through a resistor. This pin can also be used as a remote
ON/OFF and a synchronization input in both modes. See
Table 2 and Figure 11.
7. Packages with omitted pins and lead forming provide large
drain creepage distance.
For the P or G packages the LINE-SENSE and EXTERNAL
CURRENTLIMITpinfunctionsarecombinedononeMULTI-
FUNCTION (M) pin. However, some of the functions become
mutually exclusive as shown in Table 3.
8. Tighter absolute tolerances and smaller temperature
variations on switching frequency, current limit and PWM gain.
The LINE-SENSE (L) pin is usually used for line sensing by
connecting a resistor from this pin to the rectified DC high
voltage bus to implement line overvoltage (OV), under-voltage
(UV) and line feed-forward with DCMAX reduction. In this
mode,thevalueoftheresistordeterminestheOV/UVthresholds
and the DCMAX is reduced linearly starting from a line voltage
above the under-voltage threshold. See Table 2 and Figure 11.
The FREQUENCY (F) pin in the Y, R or F package sets the
switching frequency to the default value of 132 kHz when
connected to SOURCE pin. A half frequency option of
66 kHz can be chosen by connecting this pin to CONTROLpin
instead. Leaving this pin open is not recommended.
M
12/04
5
TOP242-250
CONTROL (C) Pin Operation
voltage of 5.8 V, current in excess of the consumption of the
chip is shunted to SOURCE through resistor RE as shown in
Figure2. ThiscurrentflowingthroughRE controlsthedutycycle
of the power MOSFET to provide closed loop regulation. The
shunt regulator has a finite low output impedance ZC that sets
the gain of the error amplifier when used in a primary feedback
configuration. The dynamic impedance ZC of the CONTROL
pin together with the external CONTROL pin capacitance sets
the dominant pole for the control loop.
The CONTROL pin is a low impedance node that is capable
of receiving a combined supply and feedback current. During
normal operation, a shunt regulator is used to separate the
feedbacksignalfromthesupplycurrent. CONTROLpinvoltage
VC is the supply voltage for the control circuitry including the
MOSFET gate driver. An external bypass capacitor closely
connectedbetweentheCONTROLandSOURCEpinsisrequired
tosupplytheinstantaneousgatedrivecurrent. Thetotalamount
of capacitance connected to this pin also sets the auto-restart
timing as well as control loop compensation.
When a fault condition such as an open loop or shorted output
prevents the flow of an external current into the CONTROL
pin, the capacitor on the CONTROL pin discharges towards
4.8 V. At 4.8 V, auto-restart is activated which turns the output
MOSFET off and puts the control circuitry in a low current
standby mode. The high-voltage current source turns on and
charges the external capacitance again. A hysteretic internal
supply under-voltage comparator keeps VC within a window
of typically 4.8 V to 5.8 V by turning the high-voltage current
source on and off as shown in Figure 8. The auto-restart
circuit has a divide-by-eight counter which prevents the output
MOSFET from turning on again until eight discharge/charge
cycles have elapsed. This is accomplished by enabling the
outputMOSFETonlywhenthedivide-by-eightcounterreaches
full count (S7). The counter effectively limits TOPSwitch-GX
power dissipation by reducing the auto-restart duty cycle
to typically 4%. Auto-restart mode continues until output
voltage regulation is again achieved through closure of the
feedback loop.
When rectified DC high voltage is applied to the DRAIN
pin during start-up, the MOSFET is initially off, and the
CONTROL pin capacitor is charged through a switched high
voltagecurrentsourceconnectedinternallybetweentheDRAIN
and CONTROL pins. When the CONTROL pin voltage VC
reaches approximately 5.8 V, the control circuitry is activated
and the soft-start begins. The soft-start circuit gradually
increases the duty cycle of the MOSFET from zero to the
maximum value over approximately 10 ms. If no external
feedback/supply current is fed into the CONTROL pin by the
end of the soft-start, the high voltage current source is turned
off and the CONTROL pin will start discharging in response
to the supply current drawn by the control circuitry. If the
power supply is designed properly, and no fault condition
such as open loop or shorted output exists, the feedback loop
will close, providing external CONTROL pin current, before
the CONTROL pin voltage has had a chance to discharge to
the lower threshold voltage of approximately 4.8 V (internal
supply under-voltage lockout threshold). When the externally
fed current charges the CONTROL pin to the shunt regulator
Oscillator and Switching Frequency
The internal oscillator linearly charges and discharges an
VUV
VLINE
0 V
S0
S0
S7
S1
S2
S6
S7 S0
S1
S2
S6
S7
S1 S2
S6
S7
S7
5.8 V
4.8 V
VC
0 V
VDRAIN
0 V
VOUT
0 V
1
2
3
2
4
Note: S0 through S7 are the output states of the auto-restart counter
PI-2545-082299
Figure 8. Typical Waveforms for (1) Power Up (2) Normal Operation (3) Auto-Restart (4) Power Down.
M
6
12/04
TOP242-250
internal capacitance between two voltage levels to create
a sawtooth waveform for the pulse width modulator. This
oscillator sets the pulse width modulator/current limit latch at
the beginning of each cycle.
136 kHz
Switching
Frequency
128 kHz
The nominal switching frequency of 132 kHz was chosen to
minimize transformer size while keeping the fundamental EMI
frequency below 150 kHz. The FREQUENCY pin (available
only inY, R or F package), when shorted to the CONTROLpin,
lowerstheswitchingfrequencyto66kHz(halffrequency)which
may be preferable in some cases such as noise sensitive video
applications or a high efficiency standby mode. Otherwise, the
FREQUENCY pin should be connected to the SOURCE pin
for the default 132 kHz.
4 ms
VDRAIN
Time
Figure 9. Switching Frequency Jitter (Idealized VDRAIN Waveforms).
To further reduce the EMI level, the switching frequency is
jittered (frequency modulated) by approximately ±4 kHz at
250 Hz (typical) rate as shown in Figure 9. Figure 46 shows
the typical improvement of EMI measurements with frequency
jitter.
frequency is also reduced linearly until a minimum frequency
is reached at a duty cycle of 0% (refer to Figure 7). The
minimum frequency is typically 30 kHz and 15 kHz for
132 kHz and 66 kHz operation, respectively.
This feature allows a power supply to operate at lower
frequency at light loads thus lowering the switching losses
while maintaining good cross regulation performance and low
output ripple.
Pulse Width Modulator and Maximum Duty Cycle
The pulse width modulator implements voltage mode control
by driving the output MOSFET with a duty cycle inversely
proportional to the current into the CONTROL pin that
is in excess of the internal supply current of the chip (see
Figure 7). The excess current is the feedback error signal that
appearsacrossRE (seeFigure2). ThissignalisfilteredbyanRC
network with a typical corner frequency of 7 kHz to reduce the
effect of switching noise in the chip supply current generated
by the MOSFET gate driver. The filtered error signal is
compared with the internal oscillator sawtooth waveform to
generate the duty cycle waveform. As the control current
increases, the duty cycle decreases. A clock signal from the
oscillator sets a latch which turns on the output MOSFET. The
pulse width modulator resets the latch, turning off the output
MOSFET. Note that a minimum current must be driven into
the CONTROL pin before the duty cycle begins to change.
Error Amplifier
The shunt regulator can also perform the function of an error
amplifier in primary side feedback applications. The shunt
regulator voltage is accurately derived from a temperature-
compensated bandgap reference. The gain of the error
amplifier is set by the CONTROL pin dynamic impedance.
The CONTROL pin clamps external circuit signals to the VC
voltage level. The CONTROL pin current in excess of the
supply current is separated by the shunt regulator and flows
through RE as a voltage error signal.
On-Chip Current Limit with External Programmability
The cycle-by-cycle peak drain current limit circuit uses the
output MOSFET ON-resistance as a sense resistor. A current
limit comparator compares the output MOSFET on-state drain
to source voltage, VDS(ON) with a threshold voltage. High drain
current causes VDS(ON) to exceed the threshold voltage and turns
the output MOSFET off until the start of the next clock cycle.
The current limit comparator threshold voltage is temperature
compensated to minimize the variation of the current limit due
totemperaturerelatedchangesin RDS(ON)oftheoutputMOSFET.
The default current limit of TOPSwitch-GX is preset internally.
However, with a resistor connected between EXTERNAL
CURRENT LIMIT (X) pin (Y, R or F package) or MULTI-
FUNCTION (M) pin (P or G package) and SOURCE pin,
current limit can be programmed externally to a lower level
between 30% and 100% of the default current limit. Please
refer to the graphs in the typical performance characteristics
section for the selection of the resistor value. By setting current
limit low, a larger TOPSwitch-GX than necessary for the power
The maximum duty cycle, DCMAX,is set at a default maximum
value of 78% (typical). However, by connecting the LINE-
SENSE or MULTI-FUNCTION pin (depending on the
package) to the rectified DC high voltage bus through a
resistor with appropriate value, the maximum duty cycle can
be made to decrease from 78% to 38% (typical) as shown in
Figure 11 when input line voltage increases (see line feed
forward with DCMAX reduction).
Light Load Frequency Reduction
The pulse width modulator duty cycle reduces as the load at
the power supply output decreases. This reduction in duty
cycle is proportional to the current flowing into the CONTROL
pin. As the CONTROL pin current increases, the duty cycle
decreases linearly towards a duty cycle of 10%. Below 10%
duty cycle, to maintain high efficiency at light loads, the
M
12/04
7
TOP242-250
required can be used to take advantage of the lower RDS(ON) for
higher efficiency/smaller heat sinking requirements. With
a second resistor connected between the EXTERNAL
CURRENT LIMIT (X) pin (Y, R or F package) or MULTI-
FUNCTION (M) pin (P or G package) and the rectified DC
high voltage bus, the current limit is reduced with increasing
line voltage, allowing a true power limiting operation against
line variation to be implemented. When using an RCD clamp,
this power limiting technique reduces maximum clamp
voltage at high line. This allows for higher reflected voltage
designs as well as reducing clamp dissipation.
high voltage bus sets UV threshold during power up. Once the
power supply is successfully turned on, the UV threshold is
lowered to 40% of the initial UV threshold to allow extended
input voltage operating range (UV low threshold). If the UV
low threshold is reached during operation without the power
supply losing regulation, the device will turn off and stay off
until UV (high threshold) has been reached again. If the power
supply loses regulation before reaching the UV low threshold,
the device will enter auto-restart. At the end of each auto-
restart cycle (S7), the UV comparator is enabled. If the UV
high threshold is not exceeded the MOSFET will be disabled
during the next cycle (see Figure 8). The UV feature can
be disabled independent of the OV feature as shown in
Figures 19 and 23.
The leading edge blanking circuit inhibits the current limit
comparator for a short time after the output MOSFET is turned
on. The leading edge blanking time has been set so that, if a
power supply is designed properly, current spikes caused by
primary-side capacitances and secondary-side rectifier reverse
recovery time should not cause premature termination of the
switching pulse.
Line Overvoltage Shutdown (OV)
The same resistor used for UValso sets an overvoltage threshold
which, once exceeded, will force TOPSwitch-GX output into
off-state. The ratio of OV and UV thresholds is preset at 4.5
as can be seen in Figure 11. When the MOSFET is off, the
rectified DC high voltage surge capability is increased to the
voltage rating of the MOSFET (700 V), due to the absence
of the reflected voltage and leakage spikes on the drain. A
small amount of hysteresis is provided on the OV threshold to
prevent noise triggering. The OV feature can be disabled
independent of the UV feature as shown in Figures 18 and 32.
The current limit is lower for a short period after the leading
edge blanking time as shown in Figure 52. This is due to
dynamic characteristics of the MOSFET. To avoid triggering
thecurrentlimitinnormaloperation,thedraincurrentwaveform
should stay within the envelope shown.
Line Under-Voltage Detection (UV)
At power up, UV keeps TOPSwitch-GX off until the input line
voltage reaches the under-voltage threshold. At power down,
UV prevents auto-restart attempts after the output goes out
of regulation. This eliminates power down glitches caused
by slow discharge of the large input storage capacitor present
in applications such as standby supplies. A single resistor
connected from the LINE-SENSE pin (Y, R or F package) or
MULTI-FUNCTION pin (P or G package) to the rectified DC
Line Feed-Forward with DCMAX Reduction
The same resistor used for UV and OV also implements line
voltage feed-forward, which minimizes output line ripple and
reduces power supply output sensitivity to line transients.
This feed-forward operation is illustrated in Figure 7 by the
different values of IL(Y, R or F package) or IM (Por G package).
Note that for the same CONTROL pin current, higher line
voltage results in smaller operating duty cycle. As an added
Oscillator
(SAW)
D
MAX
Enable from
X, L or M Pin (STOP)
Time
PI-2637-060600
Figure 10. Synchronization Timing Diagram.
M
8
12/04
TOP242-250
feature, the maximum duty cycle DCMAX is also reduced
from 78% (typical) at a voltage slightly higher than the UV
threshold to 30% (typical) at the OV threshold (see Figure 11).
Limiting DCMAX at higher line voltages helps prevent
transformer saturation due to large load transients in forward
converter applications. DCMAX of 38% at the OV threshold
was chosen to ensure that the power capability of the
TOPSwitch-GX is not restricted by this feature under normal
operation.
cycles between 4.8 V and 5.8 V (see CONTROL pin operation
section above) and runs entirely off the high voltage DC input,
but with very low power consumption (160 mW typical at
230 VAC with M or X pins open). When the TOPSwitch-GX
is remotely turned on after entering this mode, it will initiate
a normal start-up sequence with soft-start the next time the
CONTROLpin reaches 5.8 V. In the worst case, the delay from
remote on to start-up can be equal to the full discharge/charge
cycle time of the CONTROL pin, which is approximately
125 ms for a 47 µF CONTROL pin capacitor. This
reduced consumption remote off mode can eliminate
expensive and unreliable in-line mechanical switches. It also
allows for microprocessor controlled turn-on and turn-off
sequences that may be required in certain applications such as
inkjet and laser printers.
Remote ON/OFF and Synchronization
TOPSwitch-GX can be turned on or off by controlling the
current into the LINE-SENSE pin or out from the EXTERNAL
CURRENT LIMIT pin (Y, R or F package) and into or out
from the MULTI-FUNCTION pin (P or G package) (see
Figure 11). In addition, the LINE-SENSE pin has a 1 V
threshold comparator connected at its input. This voltage
threshold can also be used to perform remote ON/OFF
control. This allows easy implementation of remote
ON/OFF control of TOPSwitch-GX in several different ways.
A transistor or an optocoupler output connected between
the EXTERNAL CURRENT LIMIT or LINE-SENSE pins
(Y, R or F package) or the MULTI-FUNCTION pin (P or G
package) and the SOURCE pin implements this function with
“active-on” (Figures 22, 29 and 36) while a transistor or an
optocoupler output connected between the LINE-SENSE pin
(Y,RorFpackage)ortheMULTI-FUNCTION(PorGpackage)
pin and the CONTROL pin implements the function with
“active-off” (Figures 23 and 37).
Soft-Start
Two on-chip soft-start functions are activated at start-up with a
duration of 10 ms (typical). Maximum duty cycle starts from
0% and linearly increases to the default maximum of 78% at
the end of the 10 ms duration and the current limit starts from
about 85% and linearly increases to 100% at the end of the
10 ms duration. In addition to start-up, soft-start is also
activated at each restart attempt during auto-restart and when
restarting after being in hysteretic regulation of CONTROL
pin voltage (VC), due to remote OFF or thermal shutdown
conditions. This effectively minimizes current and voltage
stresses on the output MOSFET, the clamp circuit and the
output rectifier during start-up. This feature also helps
minimize output overshoot and prevents saturation of the
transformer during start-up.
When a signal is received at the LINE-SENSE pin or the
EXTERNAL CURRENT LIMIT pin (Y, R or F package) or
the MULTI-FUNCTION pin (P or G package) to disable the
output through any of the pin functions such as OV, UV and
remote ON/OFF, TOPSwitch-GX always completes its current
switching cycle, as illustrated in Figure 10, before the output is
forced off. The internal oscillator is stopped slightly before the
end of the current cycle and stays there as long as the disable
signal exists. When the signal at the above pins changes state
from disable to enable, the internal oscillator starts the next
switching cycle. This approach allows the use of these pins
to synchronize TOPSwitch-GX to any external signal with a
frequency between its internal switching frequency and 20 kHz.
Shutdown/Auto-Restart
To minimize TOPSwitch-GX power dissipation under fault
conditions, the shutdown/auto-restart circuit turns the power
supply on and off at an auto-restart duty cycle of typically 4%
if an out of regulation condition persists. Loss of regulation
interrupts the external current into the CONTROL pin. VC
regulation changes from shunt mode to the hysteretic auto-
restart mode as described in CONTROL pin operation section.
When the fault condition is removed, the power supply output
becomes regulated, VC regulation returns to shunt mode, and
normal operation of the power supply resumes.
As seen above, the remote ON/OFF feature allows the
TOPSwitch-GX to be turned on and off instantly, on a cycle-
by-cycle basis, with very little delay. However, remote
ON/OFF can also be used as a standby or power switch to
turn off the TOPSwitch-GX and keep it in a very low power
consumption state for indefinitely long periods. If the
TOPSwitch-GX is held in remote off state for long enough
time to allow the CONTROL pin to discharge to the internal
supply under-voltage threshold of 4.8 V (approximately 32 ms
for a 47 µF CONTROL pin capacitance), the CONTROL pin
goes into the hysteretic mode of regulation. In this mode, the
CONTROL pin goes through alternate charge and discharge
Hysteretic Over-Temperature Protection
Temperature protection is provided by a precision analog
circuit that turns the output MOSFET off when the junction
temperature exceeds the thermal shutdown temperature
(140 °C typical). When the junction temperature cools to
below the hysteretic temperature, normal operation resumes
providing automatic recovery. A large hysteresis of 70 °C
(typical)isprovidedtopreventoverheatingofthePC boarddue
toacontinuousfaultcondition.VC isregulatedinhystereticmode
and a 4.8 V to 5.8 V (typical) sawtooth waveform is present on
the CONTROL pin while in thermal shutdown.
M
12/04
9
TOP242-250
Bandgap Reference
may be used to lower the switching frequency from 132 kHz in
normal operation to 66 kHz in standby mode for very low
standby power consumption.
All critical TOPSwitch-GX internal voltages are derived from
a temperature-compensated bandgap reference. This reference
is also used to generate a temperature-compensated current
reference, which is trimmed to accurately set the switching
frequency, MOSFET gate drive current, current limit, and the
lineOV/UVthresholds. TOPSwitch-GXhasimprovedcircuitry
to maintain all of the above critical parameters within very tight
absolute and temperature tolerances.
LINE-SENSE (L) Pin Operation (Y, R and F Packages)
When current is fed into the LINE-SENSE pin, it works as
a voltage source of approximately 2.6 V up to a maximum
current of +400 µA (typical). At +400 µA, this pin turns into
a constant current sink. Refer to Figure 12a. In addition, a
comparator with a threshold of 1 V is connected at the pin and
is used to detect when the pin is shorted to the SOURCE pin.
High-Voltage Bias Current Source
This current source biases TOPSwitch-GX from the DRAIN
pin and charges the CONTROL pin external capacitance
during start-up or hysteretic operation. Hysteretic operation
occurs during auto-restart, remote OFF and over-temperature
shutdown. In this mode of operation, the current source
is switched on and off with an effective duty cycle of
approximately 35%. This duty cycle is determined by the
ratio of CONTROL pin charge (IC) and discharge currents
(ICD1 and ICD2). This current source is turned off during normal
operation when the output MOSFET is switching. The effect of
thecurrentsourceswitchingwillbeseenontheDRAINvoltage
waveform as small disturbances and is normal.
There are a total of four functions available through the use of
the LINE-SENSE pin: OV, UV, line feed-forward with DCMAX
reduction, and remote ON/OFF. Connecting the LINE-SENSE
pin to the SOURCE pin disables all four functions. The LINE-
SENSE pin is typically used for line sensing by connecting a
resistor from this pin to the rectified DC high voltage bus to
implement OV, UV and DCMAX reduction with line voltage. In
this mode, the value of the resistor determines the line OV/UV
thresholds, and the DCMAX is reduced linearly with rectified DC
high voltage starting from just above the UVthreshold. The pin
can also be used as a remote ON/OFF and a synchronization
input. RefertoTable2forpossiblecombinationsofthefunctions
with example circuits shown in Figure 16 through Figure 40. A
description of specific functions in terms of the LINE-SENSE
pin I/V characteristic is shown in Figure 11 (right hand side).
The horizontal axis represents LINE-SENSE pin current with
positive polarity indicating currents flowing into the pin. The
meaning of the vertical axes varies with functions. For those
that control the ON/OFF states of the output such as UV, OV
and remote ON/OFF, the vertical axis represents the enable/
disable states of the output. UV triggers at IUV (+50 µAtypical
with 30 µA hysteresis) and OV triggers at IOV (+225 µA
typical with 8 µA hysteresis). Between the UV and OV
thresholds, the output is enabled. For line feed-forward with
Using Feature Pins
FREQUENCY (F) Pin Operation
The FREQUENCY pin is a digital input pin available in the
Y, R or F package only. Shorting the FREQUENCY pin to
SOURCE pin selects the nominal switching frequency of
132 kHz (Figure 13), which is suited for most applications.
For other cases that may benefit from lower switching
frequency such as noise sensitive video applications, a
66kHzswitchingfrequency(halffrequency)canbeselectedby
shorting the FREQUENCY pin to the CONTROL pin
(Figure 14). In addition, an example circuit shown in Figure 15
LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE*
Figure Number
Three Terminal Operation
Under-Voltage
16
17
18
19
20
21
22
23
24
25
26
27
28
29
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Overvoltage
✓
Line Feed-Forward (DCMAX
Overload Power Limiting
External Current Limit
Remote ON/OFF
)
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
*This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible.
Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations.
M
10 12/04
TOP242-250
DCMAX reduction, the vertical axis represents the magnitude of
the DCMAX. Line feed-forward with DCMAX reduction lowers
maximum duty cycle from 78% at IL(DC) (+60 µA typical) to
38% at IOV (+225 µA).
for P and G packages. The comparator with a 1 V threshold
at the LINE-SENSE pin is removed in this case as shown in
Figure 2b. All of the other functions are kept intact. However,
since some of the functions require opposite polarity of input
current(MULTI-FUNCTIONpin),theyaremutuallyexclusive.
Forexample,linesensingfeaturescannotbeusedsimultaneously
with external current limit setting. When current is fed into
the MULTI-FUNCTION pin, it works as a voltage source of
approximately 2.6 V up to a maximum current of +400 µA
(typical). At +400 µA, this pin turns into a constant current
sink. When current is drawn out of the MULTI-FUNCTION
pin, it works as a voltage source of approximately 1.3 V up to
a maximum current of -240 µA (typical). At -240 µA, it turns
into a constant current source. Refer to Figure 12b.
EXTERNAL CURRENT LIMIT (X) Pin Operation
(Y, R and F Packages)
When current is drawn out of the EXTERNAL CURRENT
LIMIT pin, it works as a voltage source of approximately
1.3 V up to a maximum current of -240 µA (typical). At
-240 µA, it turns into a constant current source (refer to
Figure 12a).
There are two functions available through the use of the
EXTERNAL CURRENT LIMIT pin: external current limit
and remote ON/OFF. Connecting the EXTERNALCURRENT
LIMIT pin and SOURCE pin disables the two functions. In
high efficiency applications, this pin can be used to reduce the
current limit externally to a value close to the operating peak
current by connecting the pin to the SOURCE pin through
a resistor. The pin can also be used for remote ON/OFF.
Table2showsseveralpossiblecombinationsusingthispin. See
Figure11foradescriptionofthefunctionswherethehorizontal
axis (left hand side) represents the EXTERNAL CURRENT
LIMIT pin current. The meaning of the vertical axes varies
with function. For those that control the ON/OFF states of the
output such as remote ON/OFF, the vertical axis represents the
enable/disable states of the output. For external current limit,
the vertical axis represents the magnitude of the ILIMIT. Please
see graphs in the Typical Performance Characteristics section
for the current limit programming range and the selection of
appropriate resistor value.
There are a total of five functions available through the use
of the MULTI-FUNCTION pin: OV, UV, line feed-forward
with DCMAX reduction, external current limit and remote
ON/OFF. A short circuit between the MULTI-FUNCTION
pin and SOURCE pin disables all five functions and forces
TOPSwitch-GX to operate in a simple three terminal mode
like TOPSwitch-II. The MULTI-FUNCTION pin is typically
used for line sensing by connecting a resistor from this pin to
the rectified DC high voltage bus to implement OV, UV and
DCMAX reduction with line voltage. In this mode, the value
of the resistor determines the line OV/UV thresholds, and the
DCMAX is reduced linearly with increasing rectified DC high
voltage starting from just above the UV threshold. External
current limit programming is implemented by connecting the
MULTI-FUNCTIONpintotheSOURCEpinthrougharesistor.
However, this function is not necessary in most applications
since the internal current limit of the P and G package devices
has been reduced, compared to the Y, R and F package
devices, to match the thermal dissipation capability of the P
and G packages. It is therefore recommended that the MULTI-
FUNCTION pin is used for line sensing as described above and
not for external current limit reduction. The same pin can also
MULTI-FUNCTION (M) Pin Operation (P and G
Packages)
The LINE-SENSE and EXTERNAL CURRENT LIMIT pin
functions are combined to a single MULTI-FUNCTION pin
MULTI-FUNCTION PIN TABLE*
Figure Number
Three Terminal Operation
Under-Voltage
30
31
32
33
34
35
36
37
38
39
40
✓
✓
✓
✓
✓
✓
✓
✓
Overvoltage
✓
Line Feed-Forward (DCMAX
Overload Power Limiting
External Current Limit
Remote ON/OFF
)
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
*This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible.
Table 3. Typcial MULTI-FUNCTION Pin Configurations.
M
12/04
11
TOP242-250
M Pin
X Pin
L Pin
IREM(N)
IUV
IOV
(Enabled)
Output
MOSFET
Switching
(Disabled)
Disabled when supply
output goes out of
regulation
I
ILIMIT (Default)
Current
Limit
I
DCMAX (78.5%)
Maximum
Duty Cycle
I
-22 µA
-27 µA
VBG + VTP
VBG
Pin Voltage
I
-250
-200
-150
-100
-50
0
50
100
150
200
250
300
350
400
X and L Pins (Y, R or F Package) and M Pin (P or G Package) Current (µA)
Note: This figure provides idealized functional characteristics with typical performance values. Please refer to the parametric
table and typical performance characteristics sections of the data sheet for measured data.
PI-2636-010802
Figure 11. MULTI-FUNCTION (P or G package), LINSE-SENSE, and EXTERNAL CURRENT LIMIT (Y, R or F package) Pin Characteristics.
be used as a remote ON/OFF and a synchronization input in
both modes. Please refer to Table 3 for possible combinations
(+50 µA typical) and OV triggers at IOV (+225 µA typical with
30 µA hysteresis). Between the UV and OV thresholds, the
of the functions with example circuits shown in Figure 30
through Figure 40. Adescription of specific functions in terms
of the MULTI-FUNCTION pin I/V characteristic is shown in
Figure 11. The horizontal axis representsMULTI-FUNCTION
pincurrentwithpositivepolarityindicatingcurrentsflowinginto
the pin. The meaning of the vertical axes varies with functions.
For those that control the ON/OFF states of the output such
as UV, OV and remote ON/OFF, the vertical axis represents
the enable/disable states of the output. UV triggers at IUV
output is enabled. For external current limit and line feed-
forward with DCMAX reduction, the vertical axis represents the
magnitude of the ILIMIT and DCMAX. Line feed-forward with
DCMAX reductionlowersmaximumdutycyclefrom78%atIM(DC)
(+60 µA typical) to 38% at IOV (+225 µA). External current
limit is available only with negative MULTI-FUNCTION
pin current. Please see graphs in the Typical Performance
Characteristics section for the current limit programming
range and the selection of appropriate resistor value.
M
12 12/04
TOP242-250
Y, R and F Package
CONTROL (C)
TOPSwitch-GX
240 µA
(Negative Current Sense - ON/OFF,
Current Limit Adjustment)
VBG + VT
EXTERNAL CURRENT LIMIT (X)
LINE-SENSE (L)
(Voltage Sense)
1 V
VBG
(Positive Current Sense - Under-Voltage,
Overvoltage, ON/OFF Maximum Duty
Cycle Reduction)
400 µA
PI-2634-022604
Figure 12a. LINE-SENSE (L), and EXTERNAL CURRENT LIMIT (X) Pin Input Simplified Schematic.
P and G Package
CONTROL (C)
TOPSwitch-GX
240 µA
(Negative Current Sense - ON/OFF,
Current Limit Adjustment)
VBG + VT
MULTI-FUNCTION (M)
VBG
(Positive Current Sense - Under-Voltage,
Overvoltage, Maximum Duty
Cycle Reduction)
400 µA
PI-2548-022604
Figure 12b. MULTI-FUNCTION (M) Pin Input Simplified Schematic.
M
12/04
13
TOP242-250
Typical Uses of FREQUENCY (F) PIN
+
+
DC
Input
Voltage
DC
Input
D
S
D
CONTROL
F
CONTROL
Voltage
C
C
S
F
-
-
PI-2655-071700
PI-2654-071700
Figure 13. Full Frequency Operation (132 kHz).
Figure 14. Half Frequency Operation (66 kHz).
+
QS can be an optocoupler output.
DC
Input
D
CONTROL
F
Voltage
C
STANDBY
S
47 kΩ
QS
RHF
20 kΩ
1 nF
-
PI-2656-040501
Figure 15. Half Frequency Standby Mode (For High Standby
Efficiency).
M
14 12/04
TOP242-250
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins
+
+
VUV = IUV x RLS
VOV = IOV x RLS
For RLS = 2 MΩ
VUV = 100 VDC
VOV = 450 VDC
RLS
2 MΩ
C L
X
S
F
D
DC
DC
Input
Voltage
Input
Voltage
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
D
S
L
D
S
L
C
S
D
CONTROL
CONTROL
C
C
X
F
-
-
PI-2617-050100
PI-2618-081403
Figure 16. Three Terminal Operation (LINE-SENSE and
EXTERNAL CURRENT LIMIT Features Disabled.
FREQUENCY Pin Tied to SOURCE or CONTROL Pin).
Figure 17. Line-Sensing for Under-Voltage, Overvoltage and Line
Feed-Forward.
+
+
VUV = RLS x IUV
VOV = IOV x RLS
2 MΩ
2 MΩ
For Value Shown
VUV = 100 VDC
For Values Shown
VOV = 450 VDC
RLS
RLS
DC
Input
Voltage
DC
Input
Voltage
22 kΩ
30 kΩ
1N4148
D
S
L
D
S
M
CONTROL
CONTROL
C
C
6.2 V
-
-
PI-2510-040501
PI-2620-040501
Figure 19. Linse-Sensing for Overvoltage Only (Under-Voltage
Disabled). Maximum Duty Cycle Reduced at Low Line
and Further Reduction with Increasing Line Voltage.
Figure 18. Line-Sensing for Under-Voltage Only (Overvoltage
Disabled).
+
+
ILIMIT = 100% @ 100 VDC
For RIL = 12 kΩ
ILIMIT
=
63% @ 300 VDC
ILIMIT = 69%
RLS
2.5 MΩ
For RIL = 25 kΩ
ILIMIT = 43%
See Figure 54b for
DC
Input
Voltage
DC
D
S
D
other resistor values
Input
(RIL)
CONTROL
X
CONTROL
Voltage
C
C
S
X
RIL
RIL
6 kΩ
-
-
PI-2624-040501
PI-2623-092303
Figure 20. Externally Set Current Limit.
Figure 21. Current Limit Reduction with Line Voltage.
M
12/04
15
TOP242-250
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)
QR can be an
+
+
QR can be an optocoupler
output or can be replaced by
a manual switch.
optocoupler output or
can be replaced
by a manual switch.
QR
ON/OFF
RMC
47 kΩ
DC
Input
Voltage
DC
Input
Voltage
D
S
45 kΩ
CONTROL
C
D
L
CONTROL
C
X
ON/OFF
QR
47 KΩ
S
-
-
PI-2625-040501
PI-2621-040501
Figure 22. Active-on (Fail Safe) Remove ON/OFF.
Figure 23. Active-off Remote ON/OFF. Maximum Duty Cycle
Reduced.
+
QR can be an
+
QR can be an optocoupler
output or can be replaced
by a manual switch.
QR
optocoupler output
or can be replaced
by a manual switch.
ON/OFF
RMC
47 kΩ
For RIL =12 kΩ
45 kΩ
ILIMIT = 69%
DC
Input
Voltage
DC
Input
D
S
D
L
For RIL = 25 kΩ
CONTROL
CONTROL
ILIMIT = 43%
Voltage
C
C
X
S
X
RIL
RIL
ON/OFF
QR
47 kΩ
-
-
PI-2627-040501
PI-2626-040501
Figure 24. Active-on Remote ON/OFF with Externally Set Current
Limit.
Figure 25. Active-off Remote ON/OFF with Externally Set Current
Limit.
VUV = IUV x RLS
VOV = IOV x RLS
QR can be an optocoupler
output or can be replaced
by a manual switch.
+
+
RLS 2 MΩ
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
2 MΩ
RLS
QR
For RLS = 2 MΩ
ON/OFF
QR can be an optocoupler
output or can be replaced
by a manual switch.
47 kΩ
DC
Input
Voltage
VUV = 100 VDC
VOV = 450 VDC
D
S
L
CONTROL
DC
Input
Voltage
C
For RIL =12 kΩ
D
L
ILIMIT = 69%
CONTROL
C
X
QR
RIL
ON/OFF
S
47 kΩ
-
-
PI-2622-040501
PI-2628-040501
Figure 26. Active-off Remote ON/OFF with LINE-SENSE.
Figure 27. Active-on Remote ON/OFF with LINE-SENSE and
EXTERNAL CURRENT LIMIT.
M
16 12/04
TOP242-250
Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.)
VUV = IUV x RLS
VOV = IOV x RLS
+
+
QR can be an optocoupler
output or can be replaced by
a manual switch.
For RLS = 2 MΩ
2 MΩ
RLS
VUV = 100 VDC
VOV = 450 VDC
DC
Input
Voltage
DC
Input
Voltage
300 kΩ
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
D
S
L
D
S
L
CONTROL
CONTROL
C
C
For RIL = 12 kΩ
ILIMIT = 69%
X
See Figure 54b for
other resistor values
(RIL) to select different
ILIMIT values
ON/OFF
QR
RIL
12 kΩ
47 kΩ
-
-
PI-2640-040501
Figure 28. Line-Sensing and Externally Set Current Limit.
Figure 29. Active-on Remote ON/OFF.
Typical Uses of MULTI-FUNCTION (M) Pin
+
+
VUV = IUV x RLS
VOV = IOV x RLS
C
D
S
S
S
M
S
For RLS = 2 MΩ
VUV = 100 VDC
VOV = 450 VDC
RLS
2 MΩ
DC
Input
DC
Input
Voltage
Voltage
DCMAX@100 VDC = 78%
DCMAX@375 VDC = 38%
D
S
M
D
S
M
C
D
S
CONTROL
CONTROL
C
C
-
-
PI-2508-081199
PI-2509-040501
Figure 30. Three Terminal Operation (MULIT-FUNCTION Features
Disabled).
Figure 31. Line-Sensing for Undervoltage, Over-Voltage and Line
Feed-Forward.
+
+
VOV = IOV x RLS
VUV = RLS x IUV
2 MΩ
2 MΩ
For Values Shown
VOV = 450 VDC
For Value Shown
VUV = 100 VDC
RLS
RLS
DC
Input
Voltage
DC
Input
Voltage
22 kΩ
30 kΩ
1N4148
D
S
M
D
S
M
CONTROL
CONTROL
C
C
6.2 V
-
-
PI-2516-040501
PI-2510-040501
Figure 33. Line-Sensing for Overvoltage Only (Under-Voltage
Disabled). Maximum Duty Cycle Reduced at Low Line
and Further Rediction with Increasing Line Voltage.
Figure 32. Line-Sensing for Under-Voltage Only (Overvoltage
Disabled).
M
12/04
17
TOP242-250
Typical Uses of MULTI-FUNCTION (M) Pin (cont.)
+
+
For RIL = 12 kΩ
ILIMIT = 69%
ILIMIT = 100% @ 100 VDC
ILIMIT
=
RLS 2.5 MΩ
63% @ 300 VDC
For RIL = 25 kΩ
ILIMIT = 43%
DC
Input
Voltage
DC
Input
Voltage
See Figures 54b, 55b
and 56b for other resistor
values (RIL) to select
different ILIMIT values.
D
S
M
D
S
M
CONTROL
CONTROL
RIL
6 kΩ
C
RIL
C
-
-
PI-2517-022604
PI-2518-040501
Figure 34. Externally Set Current Limit (Not Normally Required-See
M Pin Operation Description).
Figure 35. Current Limit Reduction with Line Voltage (Not Normally
Required-See M Pin Operation Description).
+
+
QR can be an optocoupler
output or can be replaced
by a manual switch.
QR can be an optocoupler
output or can be replaced
by a manual switch.
QR
47 kΩ
DC
Input
Voltage
DC
Input
Voltage
ON/OFF
RMC
45 kΩ
D
S
M
D
M
CONTROL
CONTROL
C
QR
C
ON/OFF
47 kΩ
-
S
-
PI-2519-040501
PI-2522-040501
Figure 36. Active-on (Fail Safe) Remote ON/OFF.
Figure 37. Active-off Remote ON/OFF. Maximum Duty Cycle
Reduced.
M
18 12/04
TOP242-250
Typical Uses of MULTI-FUNCTION (M) Pin (cont.)
+
+
QR can be an optocoupler
output or can be replaced
by a manual switch.
QR can be an optocoupler
output or can be replaced
by a manual switch.
QR
For RIL = 12 kΩ
ON/OFF
ILIMIT = 69%
DC
Input
DC
Input
Voltage
47 kΩ
For RIL = 25 kΩ
Voltage
RMC
24 kΩ
RMC = 2RIL
ILIMIT = 43%
D
S
M
D
M
RIL
QR
CONTROL
CONTROL
C
RIL
C
12 kΩ
ON/OFF
47 kΩ
S
-
-
PI-2520-040501
PI-2521-040501
Figure 38. Active-on Remote ON/OFF with Externally Set Current
Limit (See M Pin Operation Description).
Figure 39. Active-off Remote ON/OFF with Externally Set Current
Limit (See M Pin Operation Description).
QR can be an optocoupler
output or can be replaced
by a manual switch.
+
RLS
2 MΩ
QR
DC
Input
ON/OFF
47 kΩ
For RLS = 2 MΩ
Voltage
D
M
VUV = 100 VDC
VOV = 450 VDC
CONTROL
C
S
-
PI-2523-040501
Figure 40. Active-off Remote ON/OFF with LINE-SENSE.
M
12/04
19
TOP242-250
TOPSwitch-GX (guaranteed minimum value of 75% vs. 64%
for TOPSwitch-II) allows the use of a smaller input capacitor
(C1). The extended maximum duty cycle and the higher
reflected voltage possible with the RCD clamp also permit
the use of a higher primary to secondary turns ratio for T1,
which reduces the peak reverse voltage experienced by the
secondary rectifier D8. As a result a 60 V Schottky rectifier
can be used for up to 15 V outputs, which greatly improves
powersupplyefficiency.Thefrequencyreductionfeatureofthe
TOPSwitch-GX eliminates the need for any dummy loading
for regulation at no load and reduces the no-load/standby
consumption of the power supply. Frequency jitter provides
improved margin for conducted EMI, meeting the CISPR 22
(FCC B) specification.
Application Examples
A High Efficiency, 30 W, Universal Input Power Supply
The circuit shown in Figure 41 takes advantage of several of
the TOPSwitch-GX features to reduce system cost and power
supply size and to improve efficiency. This design delivers
30 W at 12 V, from an 85 VAC to 265 VAC input, at an ambient
of 50 °C, in an open frame configuration. Anominal efficiency
of 80% at full load is achieved using TOP244Y.
The current limit is externally set by resistors R1 and R2 to a
value just above the low line operating peak DRAIN current
of approximately 70% of the default current limit. This
allows use of a smaller transformer core size and/or higher
transformer primary inductance for a given output power,
reducing TOPSwitch-GX power dissipation, while at the same
time avoiding transformer core saturation during startup and
output transient conditions. The resistors R1 & R2 provide a
signalthatreducesthecurrentlimitwithincreasinglinevoltage,
which in turn limits the maximum overload power at high input
line voltage. This function in combination with the built-in
soft-startfeatureofTOPSwitch-GX,allowstheuseofalowcost
RCD clamp (R3, C3 and D1) with a higher reflected voltage,
by safely limiting the TOPSwitch-GX drain voltage, with
adequate margin under worst case conditions. Resistor R4
provides line sensing, setting UV at 100 VDC and OV at
450 VDC. The extended maximum duty cycle feature of
Output regulation is achieved by using a simple Zener sense
circuit for low cost. The output voltage is determined by the
Zener diode (VR2) voltage and the voltage drops across the
optocoupler (U2) LED and resistor R6. Resistor R8 provides
bias current to Zener VR2 for typical regulation of ±5% at
the 12 V output level, over line and load and component
variations.
AHigh Efficiency, Enclosed, 70 W, UniversalAdapter Supply
The circuit shown in Figure 42 takes advantage of several of the
TOPSwitch-GX features to reduce cost, power supply size and
PERFORMANCE SUMMARY
CY1
2.2 nF
Output Power:
Regulation:
Efficiency:
Ripple:
30 W
± 4%
≥ 79%
≤ 50 mV pk-pk
C14 R15
1 nF
150 Ω
L3
3.3 µH
12 V @
2.5 A
R3
68 kΩ
2 W
C3
4.7 nF
1 kV
C12
220 µF
35 V
D8
MBR1060
C10
560 µF
35 V
C11
560 µF
35 V
BR1
600 V
2A
D1
UF4005
RTN
D2
1N4148
R4
2 MΩ
1/2 W
R6
150 Ω
L1
20 mH
R8
150 Ω
C6
0.1 µF
R1
4.7 MΩ
1/2 W
T1
C1
U2
68 µF
400 V
CX1
100 nF
250 VAC
TOPSwitch-GX
LTV817A
D
S
L
U1
TOP244Y
CONTROL
C
R5
6.8 Ω
X
F
F1
3.15 A
VR2
1N5240C
10 V, 2%
J1
R2
9.09 kΩ
L
C5
47 µF
10 V
N
PI-2657-081204
Figure 41. 30 W Power Supply using External Current Limit Programming and Line Sensing for UV and OV.
M
20 12/04
TOP242-250
increase efficiency. This design delivers 70 W at 19 V, from an
85 VAC to 265 VAC input, at an ambient of 40 °C, in a small
sealed adapter case (4” x 2.15” x 1”). Full load efficiency is
85% at 85 VAC rising to 90% at 230 VAC input.
reduce Zener clamp dissipation. With a switching frequency of
132 kHz, a PQ26/20 core can be used to provide 70 W. To
maximize efficiency, by reducing winding losses, two output
windings are used each with their own dual 100 V Schottky
rectifier (D2 and D3). The frequency reduction feature of the
TOPSwitch-GX eliminates any dummy loading to maintain
regulation at no load and reduces the no-load consumption of
the power supply to only 520 mW at 230 VAC input. Frequency
jittering provides conducted EMI meeting the CISPR 22
(FCCB)/EN55022Bspecification,usingsimplefiltercomponents
(C7, L2, L3 and C6), even with the output earth grounded.
Duetothethermalenvironmentofasealedadapter, aTOP249Y
is used to minimize device dissipation. Resistors R9 and R10
externally program the current limit level to just above the
operating peak DRAIN current at full load and low line. This
allows the use of a smaller transformer core size without
saturation during startup or output load transients. Resistors
R9 and R10 also reduce the current limit with increasing line
voltage, limiting the maximum overload power at high input
line voltage, removing the need for any protection circuitry on
the secondary. Resistor R11 implements an under-voltage and
overvoltage sense as well as providing line feed-forward for
reduced output line frequency ripple. With resistor R11 set at
2 MΩ, the power supply does not start operating until the DC
rail voltage reaches 100 VDC. On removal of the AC input,
the UV sense prevents the output glitching as C1 discharges,
turning off the TOPSwitch-GX when the output regulation is
lost or when the input voltage falls to below 40 V, whichever
occurs first. This same value of R11 sets the OV threshold to
450 V. If exceeded, for example during a line surge,
TOPSwitch-GX stops switching for the duration of the surge,
extending the high voltage withstand to 700 V without device
damage. Capacitor C11 has been added in parallel with VR1 to
To regulate the output, an optocoupler (U2) is used with a
secondary reference sensing the output voltage via a resistor
divider (U3, R4, R5, R6). Diode D4 and C15 filter and smooth
the output of the bias winding. Capacitor C15 (1 µF) prevents
the bias voltage from falling during zero to full load transients.
Resistor R8 provides filtering of leakage inductance spikes,
keeping the bias voltage constant even at high output loads.
Resistor R7, C9 and C10 together with C5 and R3 provide
loop compensation.
Due to the large primary currents, all the small signal control
components are connected to a separate source node that is
Kelvin connected to the SOURCE pin of the TOPSwitch-GX.
Forimprovedcommon-modesurgeimmunity, thebiaswinding
common returns directly to the DC bulk capacitor (C1).
PERFORMANCE SUMMARY
D2
C7 2.2 nF
Y1 Safety
C13
0.33 µF 0.022 µF 0.01 µF
400 V 400 V 400 V
C12
C11
Output Power:
Regulation:
70 W
MBR20100
± 4%
Efficiency:
Ripple:
No Load Consumption:
≥ 84%
≤ 120 mV pk-pk
< 0.52 W @ 230 VAC
D3
MBR20100
VR1
P6KE-
200
C3
C14
19 V
@ 3.6 A
820 µF
0.1 µF
L1
200 µH
BR1
25 V
50 V
D1
RS805
UF4006
8A 600 V
C2
C4
RTN
820 µF
820 µF
R1
270 Ω
D4
1N4148
25 V
25 V
L2
820 µH
2A
R11
2 MΩ
1/2 W
R4
U2
31.6 kΩ
R8
4.7 Ω
PC817A
1%
C1
T1
R2
150 µF
C15
1 µF
50 V
R5
562 Ω
1%
1 kΩ
400 V
C6
TOPSwitch-GX
D
S
L
C9
0.1 µF
TOP249Y
L3
4.7 nF 50 V
X2
CONTROL
U1
75 µH
RT1
C
R9
2A
10 Ω
t°
13 MΩ
C10
1.7 A
R3
6.8 Ω
0.1 µF
R7
56 kΩ
X
F
F1
3.15 A
50 V
U3
TL431
C8
J1
R10
R6
4.75 kΩ
1%
0.1 µF
20.5 kΩ
C5
47 µF
16 V
L
50 V
All resistors 1/8 W 5% unless otherwise stated.
N
PI-2691-042203
Figure 42. 70 W Power Supply using Current Limit Reduction with Line and Line Sensing for UV and OV.
M
12/04
21
TOP242-250
However, VR1 is essential to limit the peak drain voltage
during start-up and/or overload conditions to below the 700 V
rating of the TOPSwitch-GX MOSFET.
A High Efficiency, 250 W, 250-380 VDC Input Power Supply
The circuit shown in Figure 43 delivers 250 W (48 V @
5.2 A) at 84% efficiency using a TOP249 from a 250 VDC to
380 VDC input. DC input is shown, as typically at this power
levelap.f.c.booststagewouldpreceedthissupply,providingthe
DC input (C1 is included to provide local decoupling). Flyback
topology is still usable at this power level due to the high output
voltage, keeping the secondary peak currents low enough so
that the output diode and capacitors are reasonably sized.
The secondary is rectifed and smoothed by D2 and C9, C10 and
C11. Three capacitors are used to meet the secondary ripple
current requirement. Inductor L2 and C12 provide switching
noise filtering.
A simple Zener sensing chain regulates the output voltage.
The sum of the voltage drop of VR2, VR3 and VR4 plus the
LED drop of U2 gives the desired output voltage. Resistor R6
limits LED current and sets overall control loop DC gain.
Diode D4 and C14 provide secondary soft-finish, feeding
current into the CONTROL pin prior to output regulation and
thus ensuring that the output voltage reaches regulation at start-
up under low line, full load conditions. Resistor R9 provides a
discharge path for C14. Capacitor C13 and R8 provide control
loop compensation and are required due to the gain associated
with such a high output voltage.
In this example, the TOP249 is at the upper limit of its power
capability and the current limit is set to the internal maximum
by connecting the X pin to SOURCE. However, line sensing
is implemented by connecting a 2 MΩ resistor from the L pin
to the DC rail. If the DC input rail rises above 450 VDC, then
TOPSwitch-GX will stop switching until the voltage returns to
normal, preventing device damage.
Due to the high primary current, a low leakage inductance
transformer is essential. Therefore, a sandwich winding with
a copper foil secondary was used. Even with this technique,
the leakage inductance energy is beyond the power capability
of a simple Zener clamp. Therefore, R2, R3 and C6 are added
in parallel to VR1. These have been sized such that during
normal operation, very little power is dissipated by VR1,
the leakage energy instead being dissipated by R2 and R3.
Sufficient heat sinking is required to keep the TOPSwitch-GX
device below 110 °C when operating under full load, low line
and maximum ambient temperature. Airflow may also be
required if a large heatsink area is not acceptable.
C7
2.2 nF Y1
D2
MUR1640CT
R2
68 kΩ 68 kΩ
2 W 2 W
R3
C6
4.7 nF
1 kV
C10
560 µF 560 µF
63 V 63 V
C11
L2
3 µH 8A
+250-380
VDC
VR1
P6KE200
48 V@
5.2 A
C9
560 µF
63 V
C12
68 µF
63 V
D1
BYV26C
RTN
D2
1N4148
U2
LTV817A
R1
2 MΩ
1/2 W
R9
10 kΩ
T1
C4
1 µF
50 V
C1
22 µF
400 V
R6
100 Ω
TOPSwitch-GX
C13
150 nF
63 V
D
S
L
TOP249Y
U1
D4
PERFORMANCE SUMMARY
1N4148
CONTROL
C
Output Power:
Line Regulation:
Load Regulation:
Efficiency:
250 W
VR2 22 V
BZX79B22
± 1%
± 5%
≥ 85%
R4
C14
22 µF
63 V
X
F
6.8 Ω
VR3 12 V
BZX79B12
C3
R8
56 Ω
Ripple:
< 100 mV pk-pk
0.1 µF
C3
47 µF
10 V
No Load Consumption: ≤ 1.4 W (300 VDC)
50 V
VR4 12 V
BZX79B12
0 V
All resistor 1/8 W 5% unless
otherwise stated.
PI-2692-081204
Figure 43. 250 W, 48 V Power Supply using TOP249.
M
22 12/04
TOP242-250
to the relatively large size of C2). An optional MOV (RV1)
extends the differential surge protection to 6 kV from 4 kV.
Multiple Output, 60 W, 185-265 VAC Input Power Supply
Figure 44 shows a multiple output supply typical for high end
set-top boxes or cable decoders containing high capacity hard
disks for recording. The supply delivers an output power of
45 W continuous/60 W peak (thermally limited) from an input
voltage of 185 VAC to 265 VAC. Efficiency at 45 W,
185 VAC is ≥ 75%.
Leakage inductance clamping is provided by VR1, R5 and C5,
keeping the DRAIN voltage below 700 V under all conditions.
Resistor R5 and capacitor C5 are selected such that VR1
dissipates very little power except during overload conditions.
The frequency jittering feature of TOPSwitch-GX allows the
circuit shown to meet CISPR22B with simple EMI filtering
(C1, L1 and C6) and the output grounded.
The 3.3 V and 5 V outputs are regulated to ±5% without
the need for secondary linear regulators. DC stacking (the
secondary winding reference for the other output voltages is
connected to the cathode of D10 rather than the anode) is used
to minimize the voltage error for the higher voltage outputs.
The secondaries are rectified and smoothed by D7 to D11, C7,
C9, C11, C13, C14, C16 and C17. Diode D11 for the 3.3 V
output is a Schottky diode to maximize efficiency. Diode D10
for the 5 V output is a PN type to center the 5 V output at 5 V.
The 3.3 V and 5 V output require two capacitors in parallel to
meet the ripple current requirement. Switching noise filtering
is provided by L2 to L5 and C8, C10, C12, C15 and C18.
Resistor R6 prevents peak charging of the lightly loaded 30 V
output. The outputs are regulated using a secondary reference
(U3). Both the 3.3 V and 5 V outputs are sensed via R11
and R10. Resistor R8 provides bias for U3 and R7 sets the
overall DC gain. Resistor R9, C19, R3 and C5 provide loop
compensation. A soft-finish capacitor (C20) eliminates output
overshoot.
Due to the high ambient operating temperature requirement
typical of a set-top box (60 °C), the TOP246Y is used to
reduce conduction losses and minimize heatsink size. Resistor
R2 sets the device current limit to 80% of typical to limit
overload power. The line sense resistor (R1) protects the
TOPSwitch-GXfromlinesurgesandtransientsbysensingwhen
the DC rail voltage rises to above 450 V. In this condition the
TOPSwitch-GX stops switching, extending the input voltage
withstand to 496 VAC, which is ideal for countries with
poor power quality. A thermistor (RT1) is used to prevent
premature failure of the fuse by limiting the inrush current (due
R6
10 Ω
D7
UF4003
PERFORMANCE SUMMARY
30 V @
0.03 A
Output Power:
Regulation:
3.3 V:
5 V:
12 V:
45 W Cont./60 W Peak
C7
C8
L2
3.3 µH
3A
47 µF
10 µF
50 V
D8
50 V
UF5402
± 5%
± 5%
± 7%
± 7%
± 8%
≥75%
0.6 W
18 V @
0.5 A
C9
C10
L3
3.3 µH
3A
330 µF
100 µF
D9
UF5402
25 V
18 V:
30 V:
25 V
12 V @
0.6 A
C11
C16
1000 µF
25 V
C13
1000 µF
25 V
C12
100 µF
25 V
Efficiency:
No Load Consumption:
C6
2.2 nF
Y1
390 µF
L4
3.3 µH
5A
35 V
5 V @
3.2 A
VR1
P6KE170
R5
68 kΩ
2 W
C14
C15
220 µF
16 V
L5
3.3 µH
5A
1000 µF
D10
BYV32-200
25 V
3.3 V @
3 A
C5
1 nF
400 V
C18
D11
MBR1045
C17
1000 µF
25 V
220 µF
16 V
D1-D4
1N4007 V
RTN
D6
1N4937
C2
L1
20 mH
0.8A
68 µF
400 V
R10
D6
1N4148
C3
1 µF
50 V
R7
150 Ω
15.0
R1
kΩ
2 MΩ
C1
0.1 µF
X1
U2
LTV817
T1
1/2 W
R8
1 kΩ
R11
9.53
kΩ
TOPSwitch-GX
D
S
L
RV1
275 V
14 mm
TOP246Y
U1
CONTROL
C19
0.1 µF
R9
3.3 kΩ
C
F1
3.15 A
C3
0.1 µF
50 V
R3
6.8 Ω
X
F
J1
RT1
C20
22 µF
10 V
10 Ω
U3
TL431
C5
47 µF
10 V
R2
9.08 kΩ
L
1.7 A
R12
10 k
PI-2693-081704
N
Figure 44. 60 W Multiple Output Power Supply using TOP246.
M
12/04
23
TOP242-250
Processor Controlled Supply Turn On/Off
parking the print heads in the storage position. In the case of
productswithadiskdrive,theshutdownproceduremayinclude
savingdataorsettingstothedisk. Aftertheshutdownprocedure
is complete, when it is safe to turn off the power supply, the
microprocessor releases the M pin by turning the optocoupler
U4 off. If the manual switch and the optocouplers U3 and U4
are not locatedclose tothe M pin, a capacitorCM maybe needed
to prevent noise coupling to the pin when it is open.
A low cost momentary contact switch can be used to turn
the TOPSwitch-GX power on and off under microprocessor
control, which may be required in some applications such as
printers. The low power remote OFF feature allows an
elegant implementation of this function with very few external
components, as shown in Figure 45. Whenever the push
button momentary contact switch P1 is closed by the user, the
optocoupler U3 is activated to inform the microprocessor of
this action. Initially, when the power supply is off (M pin is
floating), closing of P1 turns the power supply on by shorting
the M pin of the TOPSwitch-GX to SOURCE through a diode
(remote ON). When the secondary output voltage VCC is
established,themicroprocessorcomesaliveandrecognizesthat
the switch P1 is closed through the switch status input that is
driven by the optocoupler U3 output. The microprocessor then
sends a power supply control signal to hold the power supply
in the on-state through the optocoupler U4. If the user presses
the switch P1 again to command a turn off, the microprocessor
detectsthisthroughtheoptocouplerU3andinitiatesashutdown
procedure that is product specific. For example, in the case of
the inkjet printer, the shutdown procedure may include safely
The power supply could also be turned on remotely through
a local area network or a parallel or serial port by driving the
optocoupler U4 input LED with a logic signal. Sometimes it is
easier to send a train of logic pulses through a cable (due toAC
coupling of cable, for example) instead of a DC logic level as
a wake up signal. In this case, a simple RC filter can be used
to generate a DC level to drive U4 (not shown in Figure 45).
This remote on feature can be used to wake up peripherals
such as printers, scanners, external modems, disk drives, etc.,
as needed from a computer. Peripherals are usually designed
to turn off automatically if they are not being used for a period
of time, to save power.
VCC
(+5 V)
+
External
Wake-up
Signal
High Voltage
DC Input
Power
Supply
ON/OFF
Control
MICRO-
PROCESSOR/
CONTROLLER
100 kΩ
U2
27 kΩ
1N4148
LOGIC LOGIC
INPUT OUTPUT
1N4148
6.8 kΩ
TOPSwitch-GX
D
S
M
U4
CONTROL
C
U3
6.8 kΩ
CM
1 nF
47 µF
F
U1
U3
LTV817A
P1 Switch
Status
P1
U4
LTV817A
RETURN
PI-2561-081204
Figure 45. Remote ON/OFF using Microcontroller.
M
24 12/04
TOP242-250
In addition to using a minimum number of components,
TOPSwitch-GX provides many technical advantages in this
type of application:
the switch and subsequent bouncing of the switch has no
effect. If necessary, the microprocessor could implement
the switch debouncing in software during turn-off, or a filter
capacitor can be used at the switch status input.
1. Extremely low power consumption in the off mode: 80 mW
typical at 110 VAC and 160 mW typical at 230 VAC. This
is because, in the remote OFF mode, the TOPSwitch-GX
consumes very little power and the external circuitry does
not consume any current (either M, Lor X pin is open) from
the high voltage DC input.
4. No external current limiting circuitry is needed for the
operation of the U4 optocoupler output due to internal
limiting of M pin current.
5. No high voltage resistors to the input DC voltage rail are
requiredtopowertheexternalcircuitryintheprimary. Even
the LED current for U3 can be derived from the CONTROL
pin. This not only saves components and simplifies layout,
but also eliminates the power loss associated with the high
voltage resistors in both ON and OFF states.
2. A very low cost, low voltage/current, momentary contact
switch can be used.
3. No debouncing circuitry for the momentary switch is
required. During turn-on, the start-up time of the power
supply (typically 10 ms to 20 ms) plus the microprocessor
initiation time act as a debouncing filter, allowing a turn-on
only if the switch is depressed firmly for at least the above
delay time. During turn-off, the microprocessor initiates
the shutdown sequence when it detects the first closure of
6. Robust design: There is no ON/OFF latch that can be
accidentally triggered by transients. Instead, the power
supply is held in the ON-state through the secondary-side
microprocessor.
M
12/04
25
TOP242-250
Key Application Considerations
TOPSwitch-II vs. TOPSwitch-GX
Table 4 compares the features and performance differences
between TOPSwitch-GX and TOPSwitch-II. Many of the new
features eliminate the need for additional discrete components.
Other features increase the robustness of design, allowing cost
savings in the transformer and other power components.
TOPSwitch-GX
Function
Figures
TOPSwitch-II TOPSwitch-GX
Advantages
Soft-Start
N/A*
N/A*
67%
10 ms
• Limits peak current and voltage
component stresses during start-
up
• Eliminates external components
used for soft-start in most
applications
• Reduces or eliminates output
overshoot
External Current
Limit
Programmable 100% 11,20,21, • Smaller transformer
to 30% of default
current limit
24,25,27, • Higher efficiency
28,34,35, • Allows power limiting (constant
38,39
overload power independent of
line voltage)
• Allows use of larger device for
lower losses, higher efficiency
and smaller heatsink
DCMAX
78%
7
• Smaller input cap (wider dynamic
range)
• Higher power capability (when
used with RCD clamp for large
VOR)
• Allows use of Schottky secondary
rectifier diode for up to 15 V
output for high efficiency
Line Feed-Forward
with DC MAX Reduction
N/A*
N/A*
N/A*
78% to 38%
7,11,17, • Rejects line ripple
26,27,28,
31,40
Line OV Shutdown
Line UV Detection
Single resistor
programmable
11,17,19, • Increases voltage withstand
26,27,28
31,33,40
capability against line surge
Single resistor
programmable
11,17,18, • Prevents auto-restart glitches
26,27,28, during power down
31,32,40
Switching Frequency 100 kHz ±10%
132 kHz ±6%
13,15
• Smaller transformer
• Below start of conducted EMI
limits
Table 4. Comparison Between TOPSwitch-II and TOPSwitch-GX (continued on next page). *Not available
M
26 12/04
TOP242-250
TOPSwitch-GX
Function
Figures
TOPSwitch-II TOPSwitch-GX
Advantages
Switching Frequency N/A*
Option (Y, R and F
Packages)
66 kHz ±7%
14,15
• Lower losses when using RC and
RCD snubber for noise reduction
in video applications
• Allows for higher efficiency in
standby mode
• Lower EMI (second harmonic
below 150 kHz)
Frequency Jitter
N/A*
±4 kHz @ 132 kHz
±2 kHz @ 66 kHz
9,46
7
• Reduces conducted EMI
Frequency Reduction N/A*
At a duty cycle below
10%
• Zero load regulation without
dummy load
• Low power consumption at
no-load
Remote ON/OFF
N/A*
Single transistor or
11,22,23, • Fast ON/OFF (cycle-by-cycle)
optocoupler interface 24,25,26, • Active-on or active-off control
or manual switch
27,29,36, • Low consumption in remote off
37,38,39, state
40
• Active-on control for fail-safe
• Eliminates expensive in-line
on/off switch
• Allows processor controlled turn
on/off
• Permits shutdown/wake-up of
peripherals via LAN or parallel
port
Synchronization
N/A*
Single transistor or
optocoupler interface
• Synchronization to external lower
frequency signal
• Starts new switching cycle on
demand
Thermal Shutdown
125 °C min.
Latched
Hysteretic 130 °C
min. shutdown (with
75 °C hysteresis)
• Automatic recovery from thermal
fault
• Large hysteresis prevents circuit
board overheating
Current Limit
Tolerance
±10% (@ 25 °C)
-8% (0 °C to
100 °C)
±7% (@ 25 °C)
-4% Typical
(0 °C to 100 °C)**
• 10% Higher power capability due
to tighter tolerance
DIP
0.037” / 0.94 mm
0.037” / 0.94 mm
0.046” / 1.17 mm
0.137” / 3.48 mm
0.137” / 3.48 mm
0.068” / 1.73 mm
0.113” / 2.87 mm
• Greater immunity to arcing as a
result of build-up of dust, debris
and other contaminants
DRAIN
Creepage
at Package
SMD
TO-220
DRAIN Creepage at 0.045” / 1.14 mm
PCB for Y, R and F
Packages
• Performed leads accommodate
large creepage for PCB layout
• Easier to meet Safety (UL/VDE)
(R and F Package (performed leads)
N/A*)
Table 4 (cont). Comparison Between TOPSwitch-II and TOPSwitch-GX. *Not available **Current limit set to internal maximum
M
12/04
27
TOP242-250
Function
TOPSwitch-GX
TOPSwitch-FX TOPSwitch-GX
Advantages
Light Load Operation Cycle skipping
Frequency and duty
cycle reduction
• Improves light load efficiency
• Reduces no-load consumption
Line Sensing/Exter-
nally Set Current
Limit (Y, R and F
Packages)
Line sensing and
externally set current
limit mutually
Line sensing and
• Additional design flexibility allows all
features to be used simultaneously
externally set current
limit possible simul-
taneously (functions
split onto L and X pins
exclusive (M pin)
Current Limit
Programming Range
100% to 40%
100% to 30%
• Minimizes transformer core size in highly
continuous designs
P/G Package Current Identical to Y
TOP243-246 P and
G packages internal
• Matches device current limit to package
dissipation capability
Limits
package
current limits reduced • Allows more continuous design to lower
device dissipation (lower RMS currents)
Y/R/F Package
Current Limits
100% (R and F
package N/A*)
90% (for equivalent
RDS(ON)
• Minimizes transformer core size
• Optomizes efficiency for most
applications
)
Thermal Shutdown
125 °C min.
70 °C hysteresis
130 °C min.
75 °C hysteresis
• Allows higher output powers in high
ambient temperature applications
90 µA
60 µA
• Reduces output line frequency ripple at
low line
• DCMAX reduction optimized for forward
design
Maximum Duty Cycle
Reduction Threshold
Line Under-Voltage
Negative (turn-off)
Threshold
N/A*
40% of positive
(turn-on) threshold
• Provides a well defined turn-off threshold
as the line voltage falls
Soft-Start
10 ms (duty cycle)
10 ms (duty cycle +
current limit)
• Gradually increasing current limit in
addition to duty cycle during soft-start
further reduces peak current and voltage
• Further reduces component stresses
during start up
Table 5. Comparison Between TOPSwitch-FX and TOPSwitch-GX. *Not available
to TOP250: Higher output voltages, with a maximum output
current of 6 A.
TOPSwitch-FX vs. TOPSwitch-GX
Table 5 compares the features and performance differences
between TOPSwitch-GX and TOPSwitch-FX. Many of the new
features eliminate the need for additional discrete components.
Other features increase the robustness of design, allowing cost
savings in the transformer and other power components.
For all devices, a 100 VDC minimum for 85-265 VAC and
250 VDC minimum for 230 VAC are assumed and sufficient
heat sinking to keep device temperature ≤100 °C. Power
levels shown in the power table for the R package device
assume 6.45 cm2 of 610 g/m2 copper heat sink area in an
enclosed adapter, or 19.4 cm2 in an open frame.
TOPSwitch-GX Design Considerations
TOPSwitch-GX Selection
Power Table
Selecting the optimum TOPSwitch-GX depends upon required
maximum output power, efficiency, heat sinking constraints
and cost goals. With the option to externally reduce current
limit, a larger TOPSwitch-GX may be used for lower power
applications where higher efficiency is needed or minimal heat
sinking is available.
Data sheet power table (Table 1) represents the maximum
practical continuous output power based on the following
conditions: TOP242 to TOP246: 12 V output, Schottky output
diode, 150 V reflected voltage (VOR) and efficiency estimates
from curves contained in application note AN-29. TOP247
M
28 12/04
TOP242-250
Input Capacitor
transformersaturationduringstart-up. Also,soft-startlimitsthe
amount of output voltage overshoot and, in many applications,
eliminates the need for a soft-finish capacitor.
Theinputcapacitormustbechosentoprovidetheminimum DC
voltage required for the TOPSwitch-GX converter to maintain
regulation at the lowest specified input voltage and maximum
output power. Since TOPSwitch-GX has a higher DCMAX than
TOPSwitch-II, it is possible to use a smaller input capacitor.
ForTOPSwitch-GX,acapacitanceof2µFperwattispossiblefor
universal input with an appropriately designed transformer.
EMI
The frequency jitter feature modulates the switching frequency
over a narrow band as a means to reduce conducted EMI peaks
associated with the harmonics of the fundamental switching
frequency. This is particularly beneficial for average detection
mode. As can be seen in Figure 46, the benefits of jitter increase
with the order of the switching harmonic due to an increase in
frequency deviation.
Primary Clamp and Output Reflected Voltage VOR
Aprimary clamp is necessary to limit the peak TOPSwitch-GX
drain to source voltage. A Zener clamp requires few parts and
takes up little board space. For good efficiency, the clamp
Zener should be selected to be at least 1.5 times the output
reflectedvoltageVOR,asthiskeepstheleakagespikeconduction
time short. When using a Zener clamp in a universal input
application, a VOR of less than 135 V is recommended to allow
for the absolute tolerances and temperature variations of the
Zener. This will ensure efficient operation of the clamp circuit
and will also keep the maximum drain voltage below the rated
breakdown voltage of the TOPSwitch-GX MOSFET.
The FREQUENCY pin of TOPSwitch-GX offers a switching
frequency option of 132 kHz or 66 kHz. In applications that
require heavy snubbers on the drain node for reducing high
80
70
60
50
40
30
20
-10
0
TOPSwitch-II (no jitter)
AhighVOR isrequiredtotakefulladvantageofthewiderDCMAX
of TOPSwitch-GX. An RCD clamp provides tighter clamp
voltage tolerance than a Zener clamp and allows a VOR as high
as150V. RCDclampdissipationcanbeminimizedbyreducing
the external current limit as a function of input line voltage (see
Figures 21 and 35). The RCD clamp is more cost effective than
the Zener clamp but requires more careful design (see Quick
Design Checklist).
EN55022B (QP)
EN55022B (AV)
-10
-20
0.15
1
10
30
Output Diode
Frequency (MHz)
The output diode is selected for peak inverse voltage, output
current, and thermal conditions in the application (including
heatsinking, air circulation, etc.). The higher DCMAX of
TOPSwitch-GX, along with an appropriate transformer turns
ratio, can allow the use of a 60 V Schottky diode for higher
efficiency on output voltages as high as 15 V (see Figure 41: A
12 V, 30 W design using a 60 V Schottky for the output diode).
Figure 46a. TOPSwitch-II Full Range EMI Scan (100 kHz, No
Jitter).
80
70
60
TOPSwitch-GX (with jitter)
50
40
30
20
-10
0
Bias Winding Capacitor
Due to the low frequency operation at no-load a 1 µF bias
winding capacitor is recommended.
Soft-Start
Generally, a power supply experiences maximum stress at
start-up before the feedback loop achieves regulation. For a
periodof10ms,theon-chipsoft-startlinearlyincreasestheduty
cycle from zero to the default DCMAX at turn on. In addition,
the primary current limit increases from 85% to 100% over the
same period. This causes the output voltage to rise in an orderly
manner, allowing time for the feedback loop to take control of
the duty cycle. This reduces the stress on the TOPSwitch-GX
MOSFET, clamp circuit and output diode(s), and helps prevent
EN55022B (QP)
EN55022B (AV)
-10
-20
0.15
1
10 30
Frequency (MHz)
Figure 46b. TOPSwitch-GX Full Range EMI Scan (132 kHz, With
Jitter) with Identical Circuitry and Conditions.
M
12/04
29
TOP242-250
SOURCE connection trace should not be shared by the main
MOSFET switching currents. All SOURCE pin referenced
components connected to the MULTI-FUNCTION, LINE-
SENSE or EXTERNAL CURRENT LIMIT pins should
also be located closely between their respective pin and
SOURCE. Once again, the SOURCE connection trace of these
components should not be shared by the main MOSFET
switching currents. It is very critical that SOURCE pin
switching currents are returned to the input capacitor negative
terminal through a seperate trace that is not shared by the
components connected to CONTROL, MULTI-FUNCTION,
LINE-SENSE or EXTERNAL CURRENT LIMIT pins. This
is because the SOURCE pin is also the controller ground
reference pin.
frequency radiated noise (for example, video noise sensitive
applications such as VCR, DVD, monitor, TV, etc.), operating
at 66 kHz will reduce snubber loss resulting in better efficiency.
Also, in applications where transformer size is not a concern,
use of the 66 kHz option will provide lower EMI and higher
efficiency. Note that the second harmonic of 66 kHz is still
below 150 kHz, above which the conducted EMI specifications
get much tighter.
For 10 W or below, it is possible to use a simple inductor in
place of a more costly AC input common mode choke to meet
worldwide conducted EMI limits.
Transformer Design
It is recommended that the transformer be designed for
maximum operating flux density of 3000 Gauss and a peak flux
densityof4200Gaussatmaximumcurrentlimit. Theturnsratio
should be chosen for a reflected voltage (VOR) no greater than
135 V when using a Zener clamp, or 150 V (max) when using
an RCD clamp with current limit reduction with line voltage
(overload protection).
Any traces to the M, L or X pins should be kept as short as
possible and away from the DRAIN trace to prevent noise
coupling. LINE-SENSE resistor (R1 in Figures 47-49) should
be located close to the M or L pin to minimize the trace length
on the M or L pin side.
In addition to the 47 µF CONTROL pin capacitor, a high
frequency bypass capacitor in parallel may be used for better
noise immunity. The feedback optocoupler output should
also be located close to the CONTROL and SOURCE pins of
TOPSwitch-GX.
For designs where operating current is significantly lower than
the default current limit, it is recommended to use an externally
setcurrentlimitclosetotheoperatingpeakcurrenttoreducepeak
flux density and peak power (see Figures 20 and 34). In most
applications,thetightercurrentlimittolerance,higherswitching
frequency and soft-start features of TOPSwitch-GX contribute
to a smaller transformer when compared to TOPSwitch-II.
Y-Capacitor
The Y-capacitor should be connected close to the secondary
output return pin(s) and the positive primary DC input pin of
the transformer.
Standby Consumption
Frequency reduction can significantly reduce power loss at
light or no load, especially when a Zener clamp is used. For
very low secondary power consumption, use aTL431 regulator
for feedback control. Alternately, switching losses can be
significantly reduced by changing from 132 kHz in normal
operation to 66 kHz under light load conditions.
Heat Sinking
The tab of the Y package (TO-220) or F package (TO-262)
is internally electrically tied to the SOURCE pin. To avoid
circulating currents, a heat sink attached to the tab should not
be electrically tied to any primary ground/source nodes on the
PC board.
TOPSwitch-GX Layout Considerations
When using a P (DIP-8), G (SMD-8) or R (TO-263) package,
a copper area underneath the package connected to the
SOURCE pins will act as an effective heat sink. On double
sided boards (Figure 49), top side and bottom side areas
connected with vias can be used to increase the effective heat
sinking area.
As TOPSwitch-GX has additional pins and operates at
muchhigherpowerlevelscomparedtopreviousTOPSwitch
families, the following guidelines should be carefully
followed.
Primary Side Connections
In addition, sufficient copper area should be provided at
the anode and cathode leads of the output diode(s) for heat
sinking.
Use a single point (Kelvin) connection at the negative terminal
of the input filter capacitor for the TOPSwitch-GX SOURCE
pin and bias winding return. This improves surge capabilities
by returning surge currents from the bias winding directly to
the input filter capacitor.
In Figures 47, 48 and 49, a narrow trace is shown between
the output rectifier and output filter capacitor. This trace acts
as a thermal relief between the rectifier and filter capacitor to
prevent excessive heating of the capacitor.
The CONTROL pin bypass capacitor should be located as
close as possible to the SOURCE and CONTROL pins and its
M
30 12/04
TOP242-250
Maximize hatched copper
Safety Spacing
areas (
) for optimum
heat sinking
Y1-
Capacitor
+
Output Rectifier
Output Filter Capacitor
HV
-
Input Filter Capacitor
T
r
PRI
SEC
BIAS
a
n
s
f
PRI
S
S
D
o
r
m
e
r
TOPSwitch-GX
BIAS
TOP VIEW
S
S
C
M
Opto-
coupler
R1
DC
Out
-
+
R2
PI-2670-042301
Figure 47. Layout Consideratiions for TOPSwitch-GX using P or G Package.
Safety Spacing
Y1-
Maximize hatched copper
+
Capacitor
areas (
) for optimum
heat sinking
Input Filter Capacitor
HV
Output Rectifier
Output Filter Capacitor
-
T
r
SEC
a
n
s
f
TOPSwitch-GX
D
o
r
X
L
m
e
r
C
TOP VIEW
Opto-
coupler
R1
Heat Sink
DC
Out
-
+
PI-2669-042301
Figure 48. Layout Consideratiions for TOPSwitch-GX using Y or F Package
M
12/04
31
TOP242-250
Output Filter Capacitors
Solder Side
Safety Spacing
Component Side
Y1-
+
Capacitor
TOP VIEW
HV
T
r
a
n
s
f
o
r
m
e
r
PRI
PRI
Input Filter
Capacitor
SEC
-
R1a - 1c
BIAS
D
S
X
L
DC
Out
-
+
C
Opto-
coupler
Maximize hatched copper
areas (
) for optimum
heat sinking
TOPSwitch-GX
PI-2734-043001
Figure 49. Layout Considerations for TOPSwitch-GX using R Package.
3. Thermal check – At maximum output power, minimum
input voltage and maximum ambient temperature, verify
that temperature specifications are not exceeded for
TOPSwitch-GX, transformer, output diodes and output
capacitors. Enough thermal margin should be allowed for
the part-to-part variation of the RDS(ON) of TOPSwitch-GX,
as specified in the data sheet. The margin required can
either be calculated from the tolerances or it can be
accounted for by connecting an external resistance in
series with the DRAIN pin and attached to the same
heatsink, having a resistance value that is equal to the
difference between the measured RDS(ON) of the device
under test and the worst case maximum specification.
Quick Design Checklist
As with any power supply design, all TOPSwitch-GX designs
should be verified on the bench to make sure that components
specificationsarenotexceededunderworstcaseconditions.The
following minimum set of tests is strongly recommended:
1. Maximum drain voltage – Verify that peak VDS does not
exceed 675 V at highest input voltage and maximum
overload output power. Maximum overload output power
occurswhentheoutputisoverloadedtoaleveljustbeforethe
power supply goes into auto-restart (loss of regulation).
2. Maximumdraincurrent–Atmaximumambienttemperature,
maximum input voltage and maximum output load, verify
drain current waveforms at start-up for any signs of
transformer saturation and excessive leading edge current
spikes. TOPSwitch-GX has a leading edge blanking time of
220 ns to prevent premature termination of the ON-cycle.
Verify that the leading edge current spike is below the
allowed current limit envelope (see Figure 52) for the
drain current waveform at the end of the 220 ns blanking
period.
Design Tools
For a discussion on utilizing TOPSwitch-GX in a forward
converter configuration, please refer to the TOPSwitch-GX
Forward Design Methodology Application Note.
Up-to-date information on design tools can be found at the
Power Integrations website: www.powerint.com
M
32 12/04
TOP242-250
ABSOLUTE MAXIMUM RATINGS(1)
DRAIN Voltage ..................................................-0.3Vto700V CONTROL Current .................................................... 100 mA
DRAIN Peak Current: TOP242......................................0.72 A LINE SENSE Pin Voltage ...................................-0.3 V to 9 V
TOP243.......................................1.44 A CURRENT LIMIT Pin Voltage ........................-0.3 V to 4.5 V
TOP244..........................................2.16A MULTI-FUNCTION Pin Voltage ........................-0.3 V to 9 V
TOP245.......................................2.88 A FREQUENCY Pin Voltage ..................................-0.3 V to 9 V
TOP246..........................................4.32 A Storage Temperature ..................................... -65 °C to 150 °C
TOP247..........................................5.76 A Operating Junction Temperature(2) ................ -40 °C to 150 °C
TOP248..........................................7.20 A Lead Temperature(3) ...................................................... 260 °C
TOP249..........................................8.64 A Notes:
TOP250........................................10.08A 1. All voltages referenced to SOURCE, TA = 25 °C.
CONTROLVoltage ................................................ -0.3Vto 9V 2. Normally limited by internal circuitry.
3. 1/16 in. from case for 5 seconds.
THERMAL IMPEDANCE
Thermal Impedance: Y or F Package:
Notes:
(θJA)(1) ...............................................80 °C/W 1. Free standing with no heatsink.
(θJC)(2) .................................................2 °C/W 2. Measured at the back surface of tab.
P or G Package:
3. Soldered to 0.36 sq. in. (232 mm2), 2 oz. (610 g/m2)
(θJA) ............................ 70 °C/W(3); 60 °C/W(4)
copper clad.
(θJC)(5)................................................ 11 °C/W 4. Soldered to 1 sq. in. (645 mm2), 2 oz. (610 g/m2) copper clad.
R Package:
5. Measured on the SOURCE pin close to plastic interface.
(θJA) ..........80 °C/W(7);40 °C/W(4); 30 °C/W(6) 6. Soldered to 3 sq. in. (1935 mm2), 2 oz. (610 g/m2) copper clad.
(θJC)(5)..................................................2 °C/W 7. Soldered to foot print area, 2 oz. (610 g/m2) copper clad.
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
Parameter
Symbol
Min
Typ
Max
Units
See Figure 53
(Unless Otherwise Specified)
CONTROL FUNCTIONS
FREQUENCY Pin
Connected to SOURCE
124
132
66
140
Switching
Frequency
(average)
IC = 3 mA;
TJ = 25 °C
fOSC
kHz
FREQUENCY Pin
Connected to CONTROL
61.5
70.5
Duty Cycle at
ONSET of
Frequency
Reduction
DC(ONSET)
10
%
Switching
Frequency near
0% Duty Cycle
132 kHz Operation
66 kHz Operation
30
15
fOSC(DMIN)
kHz
132 kHz Operation
66 kHz Operation
±4
±2
Frequency Jitter
Deviation
∆f
kHz
Hz
Frequency Jitter
Modulation Rate
fM
250
M
12/04
33
TOP242-250
Parameter
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
See Figure 53
Symbol
Min
Typ
Max
Units
(Unless Otherwise Specified)
CONTROL FUNCTIONS (cont.)
IL ≤ IL(DC) or IM ≤ IM(DC)
75
28
78
38
83
50
IL or IM = 190 µA
TOP242-245
IL or IM = 100 µA
Maximum Duty
Cycle
66.5
41.3
66.8
DCMAX
IC = ICD1
%
TOP242-245
IL or IM = 190 µA
TOP246-250
33
60
49.5
73.5
IL or IM = 100 µA
TOP246-250
tSOFT
TJ = 25 °C; DCMIN to DCMAX
IC = 4 mA; TJ = 25 °C
10
15
ms
Soft-Start Time
PWM Gain
DCreg
-28
-23
-18
%/mA
PWM Gain
Temperature Drift
See Note A
-0.01
%/mA/°C
mA
TOP242-245
1.2
1.6
1.7
2.0
2.6
2.7
6.0
6.6
7.3
3.0
4.0
4.2
7.0
8.0
8.5
External Bias
Current
IB
See Figure 7
TOP246-249
TOP250
TOP242-245
TOP246-249
TOP250
CONTROL
Current at 0%
Duty Cycle
IC(OFF)
TJ = 25 °C
mA
Ω
Dynamic
Impedance
IC = 4 mA; TJ = 25 °C
See Figure 51
ZC
10
15
0.18
7
22
Dynamic
Impedance
Temperature Drift
%/°C
kHz
CONTROL Pin
Internal Filter Pole
SHUTDOWN/AUTO-RESTART
VC = 0 V
VC = 5 V
-5.0
-3.0
-3.5
-1.8
-2.0
-0.6
CONTROL Pin
Charging Current
IC(CH)
TJ = 25 °C
mA
Charging Current
Temperature Drift
See Note A
0.5
%/°C
Auto-Restart
VC(AR)U
5.8
V
Upper Threshold
Voltage
Auto-Restart
Lower Threshold
Voltage
VC(AR)L
4.5
0.8
4.8
1.0
5.1
V
V
Auto-Restart
Hysteresis Voltage
VC(AR)hyst
M
34 12/04
TOP242-250
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
See Figure 53
Parameter
Symbol
Min
Typ
Max
Units
(Unless Otherwise Specified)
SHUTDOWN/AUTO-RESTART (cont.)
Auto-Restart Duty
DC(AR)
Cycle
4
8
%
Auto-Restart
f(AR)
Frequency
1.0
Hz
MULTI-FUNCTION (M), LINE-SENSE (L) AND EXTERNAL CURRENT LIMIT (X) INPUTS
Line Under-
Threshold
Hysteresis
44
50
30
54
µA
µA
Voltage Threshold
Current and Hys-
teresis (M or L Pin)
IUV
TJ = 25 °C
Line Overvoltage
or Remote ON/OFF
Threshold Current
and Hysteresis
(M or L Pin)
Threshold
Hysteresis
210
225
8
240
µA
µA
V
IOV
TJ = 25 °C
L Pin Voltage
Threshold
VL(TH)
0.5
-35
1.0
-27
5
1.6
-20
Remote ON/OFF
Negative
Threshold Current
and Hysteresis
(M or X Pin)
Threshold
Hysteresis
µA
IREM (N)
TJ = 25 °C
µA
µA
µA
V
L or M Pin Short
Circuit Current
IL(SC) or
IM(SC)
VL, VM = VC
300
400
520
Normal Mode
Auto-Restart Mode
IL or IM = 50 µA
IL or IM = 225 µA
IX = -50 µA
-300
-110
1.90
2.30
1.26
1.18
1.24
1.13
-240
-90
-180
-70
X or M Pin Short
Circuit Current
IX(SC) or
IM(SC)
VX, VM = 0 V
2.50
2.90
1.33
1.24
1.31
1.19
3.00
3.30
1.40
1.30
1.39
1.25
L or M Pin Voltage
(Positive Current)
VL, VM
X Pin Voltage
(Negative Current)
VX
V
IX = -150 µA
IM = -50 µA
M Pin Voltage
(Negative Current)
VM
V
IM = -150 µA
Maximum Duty
Cycle Reduction
Onset Threshold
Current
IL(DC) or
IM(DC)
TJ = 25 °C
40
60
75
µA
M
12/04
35
TOP242-250
Parameter
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
See Figure 53
Symbol
Min
Typ
Max
Units
(Unless Otherwise Specified)
MULTI-FUNCTION, LINSE-SENSE AND EXTERNAL CURRENT LIMIT INPUTS (cont.)
X, L or M Pin
0.6
1.0
2.5
1.0
Remote OFF
DRAIN Supply
Current
See Figure 71
VDRAIN = 150 V
TJ = 25 °C
Floating
ID(RMT)
mA
L or M Pin Shorted
to CONTROL
1.6
From Remote ON to Drain Turn-On
See Note B
tR(ON)
µs
µs
Remote ON Delay
Remote OFF
Setup Time
Minimum Time Before Drain Turn-On
to Disable Cycle, See Note B
tR(OFF)
2.5
FREQUENCY INPUT
FREQUENCY Pin
Threshold Voltage
VF
IF
See Note B
VF = VC
2.9
40
V
FREQUENCY Pin
Input Current
10
100
µA
CIRCUIT PROTECTION
TOP242 P/G
TOP242 Y/R/F
TJ = 25 °C
Internal
di/dt = 90 mA/µs
0.418
0.45
0.481
TOP243 P/G
TJ = 25 °C
Internal
di/dt = 150 mA/µs
0.697
0.837
0.930
1.256
1.02
0.75
0.90
1.00
1.35
1.10
1.80
1.35
2.70
3.60
4.50
5.40
0.802
0.963
1.070
1.445
1.18
TOP243 Y/R/F
TJ = 25 °C
Internal
di/dt = 180 mA/µs
TOP244 P/G
TJ = 25 °C
Internal
di/dt = 200 mA/µs
TOP244 Y/R/F
TJ = 25 °C
Internal
di/dt = 270 mA/µs
TOP245 P
TJ = 25 °C
Internal
di/dt = 220 mA/µs
Self Protection
TOP245 Y/R/F
TJ = 25 °C
Internal
di/dt = 360 mA/µs
ILIMIT
A
Current Limit
(See Note C)
1.674
1.256
2.511
3.348
4.185
5.022
1.926
1.445
2.889
3.852
4.815
5.778
TOP246 P
TJ = 25 °C
Internal
di/dt = 270 mA/µs
TOP246 Y/R/F
TJ = 25 °C
Internal
di/dt = 540 mA/µs
TOP247 Y/R/F
TJ = 25 °C
Internal
di/dt = 720 mA/µs
TOP248 Y/R/F
TJ = 25 °C
Internal
di/dt = 900 mA/µs
TOP249 Y/R/F
TJ = 25 °C
Internal
di/dt = 1080 mA/µs
TOP250 Y/R/F
TJ = 25 °C
Internal
di/dt = 1260 mA/µs
5.859
6.30
6.741
M
36 12/04
TOP242-250
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
See Figure 53
Parameter
Symbol
Min
Typ
Max
Units
(Unless Otherwise Specified)
CIRCUIT PROTECTION (cont.)
≤85 VAC
(Rectified Line Input)
0.75 x
ILIMIT(MIN)
IINIT
See Note B
A
Initial Current Limit
265 VAC
0.6 x
ILIMIT(MIN)
(Rectified Line Input)
Leading Edge
Blanking Time
See Figure 52
TJ = 25 °C, IC = 4 mA
tLEB
220
100
140
ns
ns
°C
Current Limit
Delay
tIL(D)
IC = 4 mA
Thermal Shut-
down Temperature
130
150
Thermal Shut-
/=*down Hyster-
esis
Ω
75
°C
Power-Up Reset
Threshold Voltage
VC(RESET)
Figure 53, S1 Open
1.75
3.0
4.25
V
OUTPUT
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
TJ = 25 °C
TJ = 100 °C
15.6
25.7
7.80
12.9
5.20
8.60
3.90
6.45
2.60
4.30
1.95
3.22
1.56
2.58
1.30
2.15
1.10
1.85
18.0
30.0
9.00
15.0
6.00
10.0
4.50
7.50
3.00
5.00
2.25
3.75
1.80
3.00
1.50
2.50
1.28
2.15
TOP242
ID = 50 mA
TOP243
ID = 100 mA
TOP244
ID = 150 mA
TOP245
ID = 200 mA
ON-State
Resistance
TOP246
ID = 300 mA
RDS(ON)
Ω
TOP247
ID = 400 mA
TOP248
ID = 500 mA
TOP249
ID = 600 mA
TOP250
ID = 700 mA
OFF-State Drain
Leakage Current
VL, VM = Floating; IC = 4 mA
VDS = 560 V; TJ = 25 °C
IDSS
470
µA
V
Breakdown
Voltage
VL, VM = Floating; IC = 4 mA
See Note D, TJ = 25 °C
BVDSS
700
M
12/04
37
TOP242-250
Parameter
Conditions
SOURCE = 0 V; TJ = -40 to 125 °C
See Figure 53
Symbol
Min
Typ
Max
Units
(Unless Otherwise Specified)
OUTPUT (cont.)
Rise Time
tR
tF
100
50
ns
ns
Measured in a Typical Flyback
Converter Application
Fall Time
SUPPLY VOLTAGE CHARACTERISTICS
DRAIN Supply
Voltage
See Note E
36
V
V
Shunt Regulator
Voltage
VC(SHUNT)
IC = 4 mA
5.60
5.85
±50
6.10
Shunt Regulator
Temperature Drift
ppm/°C
TOP242-245
1.0
1.2
1.3
1.6
2.2
2.4
2.5
3.2
Output MOSFET
Enabled
VX, VL, VM = 0 V
ICD1
TOP246-249
TOP250
3.65
Control Supply/
Discharge Current
mA
Output MOSFET
ICD2
Disabled
0.3
0.6
1.3
VX, VL, VM = 0 V
NOTES:
A. For specifications with negative values, a negative temperature coefficient corresponds to an increase in
magnitude with increasing temperature, and a positive temperature coefficient corresponds to a decrease in
magnitude with increasing temperature.
B. Guaranteed by characterization. Not tested in production.
C. For externally adjusted current limit values, please refer to Figures 54b, 55b and 56b (Current Limit vs. External
Current Limit Resistance) in the Typical Performance Characteristics section. The tolerance specified is only valid
at full current limit.
D. Breakdown voltage may be checked against minimum BVDSS specification by ramping the DRAIN pin voltage up
to but not exceeding minimum BVDSS
.
E. It is possible to start up and operate TOPSwitch-GX at DRAIN voltages well below 36 V. However, the CONTROL
pin charging current is reduced, which affects start-up time, auto-restart frequency, and auto-restart duty cycle.
Refer to Figure 68, the characteristic graph on CONTROL pin charge current (IC) vs. DRAIN voltage for low
voltage operation characteristics.
M
38 12/04
TOP242-250
t
2
t
1
HV
90%
90%
t
t
DRAIN
VOLTAGE
1
2
D =
10%
0 V
PI-2039-033001
Figure 50. Duty Cycle Measurement.
t
(Blanking Time)
LEB
120
100
80
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
I
@ 85 VAC
INIT(MIN)
60
I
@ 265 VAC
INIT(MIN)
40
I
I
@ 25 °C
@ 25 °C
LIMIT(MAX)
LIMIT(MIN)
Dynamic
Impedance
1
=
Slope
20
0
0
2
4
6
8
10
0
1
2
3
4
5
6
7
8
CONTROL Pin Voltage (V)
Figure 51. CONTROL Pin I-V Characteristic.
Time (µs)
Figure 52. Drain Current Operating Envelope.
Y or R Package (X and L Pins)
P or G Package (M Pin)
0-100 kΩ
S1
470 Ω
5 W
0-100 kΩ
S5
5-50 V
M
5-50 V
0-60 kΩ
40 V
L
D
CONTROL
470 Ω
C
TOPSwitch-GX
S2
F
X
S
S4
0-15 V
S3
0-60 kΩ
47 µF
0.1 µF
NOTES: 1. This test circuit is not applicable for current limit or output characteristic measurements.
2. For P and G packages, short all SOURCE pins together.
PI-2631-081204
Figure 53. TOPSwitch-GX General Test Circuit.
M
12/04
39
TOP242-250
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS
The following precautions should be followed when testing
TOPSwitch-GX by itself outside of a power supply. The
schematicshowninFigure53issuggestedforlaboratorytesting
of TOPSwitch-GX.
while in this auto-restart mode, there is only a 12.5% chance
that the CONTROL pin oscillation will be in the correct state
(drainactivestate)sothatthecontinuousdrainvoltagewaveform
may be observed. It is recommended that the VC power supply
be turned on first and the DRAIN pin power supply second if
continuous drain voltage waveforms are to be observed. The
12.5% chance of being in the correct state is due to the divide-
by-8 counter. Temporarily shorting the CONTROL pin to the
SOURCE pin will reset TOPSwitch-GX, which then will come
up in the correct state.
When the DRAIN pin supply is turned on, the part will be
in the auto-restart mode. The CONTROL pin voltage will be
oscillating at a low frequency between 4.8 V and 5.8 V and
the drain is turned on every eigth cycle of the CONTROL pin
oscillation. If the CONTROL pin power supply is turned on
Typical Performance Characteristics
PI-2653-031904
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factors:
TOP242 P/G/Y/R/F: .45
200
TOP243 P/G:
TOP243 Y/R/F:
TOP244 P/G:
.75
.90
1
180
160
140
TOP244 Y/R/F:
TOP245 Y/R/F:
TOP246 Y/R/F:
TOP247 Y/R/F:
TOP248 Y/R/F
TOP249 Y/R/F:
TOP250 Y/R/F:
1.35
1.80
2.70
3.60
4.50
5.40
6.32
120
100
80
60
0.2
-250
40
0
-200
-150
-100
-50
IX or IM (µA)
Figure 54a. Current Limit vs. X or M Pin Current (see Figures 55a and 56a for TOP245P and TOP246P).
PI-2652-042303
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factors:
TOP242 P/G/Y/R/F: .45
200
180
TOP243 P/G:
.75
.90
1
TOP243 Y/R/F:
TOP244 P/G:
160
140
TOP244 Y/R/F:
TOP245 Y/R/F:
TOP246 Y/R/F:
TOP247 Y/R/F:
TOP248 Y/R/F
TOP249 Y/R/F:
TOP250 Y/R/F:
1.35
1.80
2.70
3.60
4.50
5.40
6.32
Maximum
Minimum
120
100
80
Typical
Maximum and minimum levels
are based on characterization.
60
40
0.2
0
5K
10K
15K
20K
25K
30K
35K
40K
45K
External Current Limit Resistor RIL (Ω)
Figure 54b. Current Limit vs. External Current Limit Resistance (see Figures 55b and 56b for TOP245P and
TOP246P).
M
40 12/04
TOP242-250
PI-3652-031904
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factor:
TOP245P: 1.1
200
180
160
140
120
100
80
60
0.2
-250
40
-200
-150
-100
-50
0
IM (µA)
Figure 55a. Current Limit vs. MULTI-FUNCTION Pin Current (TOP245P only).
PI-3651-031804
1.1
1.0
0.9
0.8
Scaling Factor:
TOP245P: 1.1
200
180
160
140
120
100
80
Refer to MULTIFUNCTION (M) Pin
Operation section
0.7
0.6
Typical
0.5
0.4
Measured at 25 °C.
0.3
60
0.2
40
45K
0
5K
10K
15K
20K
25K
30K
35K
40K
External Current Limit Resistor RIL (Ω)
Figure 55b. Current Limit vs. External Current Limit Resistance (TOP245P only).
1.25
1.20
1.15
0 °C
1.10
1.05
1.00
.95
25 °C
.90
.85
.80
.75
.70
100 °C
0
5K
10K
15K
20K
25K
30K
35K
40K
45K
External Current Limit Resistor RIL (Ω)
Figure 55c. External Current Limit vs. External Current Limit Resistance at 0 °C, 25 °C and 100 °C Junction
Temperature (TOP245P only).
M
12/04
41
TOP242-250
PI-3724-012704
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
Scaling Factor:
TOP246P: 1.35
200
180
160
140
120
100
80
60
0.2
40
-250
-200
-150
-100
-50
0
IM (µA)
Figure 56a. Current Limit vs. MULTI-FUNCTION Pin Current (TOP246P only).
PI-3725-031804
1.1
1.0
0.9
0.8
Scaling Factor:
TOP246P: 1.35
200
180
160
140
120
100
80
Refer to MULTIFUNCTION (M) Pin
0.7
Operation section
0.6
Typical
0.5
0.4
Measured at 25 °C.
0.3
60
0.2
40
0
5K
10K
15K
20K
25K
30K
35K
40K
45K
External Current Limit Resistor RIL (Ω)
Figure 56b. Current Limit vs. External Current Limit Resistance (TOP246P only).
1.25
1.20
0 °C
1.15
1.10
1.05
1.00
.95
25 °C
.90
.85
.80
100 °C
.75
.70
0
5K
10K
15K
20K
25K
30K
35K
40K
45K
External Current Limit Resistor RIL (Ω)
Figure 56c. External Current Limit vs. External Current Limit Resistance at 0 °C, 25 °C and 100 °C Junction
Temperature (TOP246P only).
M
42 12/04
TOP242-250
Typical Performance Characteristics (cont.)
1.1
1.2
1.0
0.8
0.6
0.4
1.0
0.9
0.2
0
-50 -25
0
25 50 75 100 125 150
-50 -25
0
25 50 75 100 125 150
Junction Temperature (°C)
Junction Temperature (°C)
Figure 57. Breakdown Voltage vs. Temperature.
Figure 58. Frequency vs. Temperature.
1.2
1.0
0.8
0.6
0.4
0.2
1.2
1.0
0.8
0.6
Use for TOP242-250 Y/R/F
packages and TOP242-244 P/G
packages only. See Figures 55c
and 56c for TOP245P and
0.4
0.2
TOP246P.
0
0
-50 -25
0
25 50 75 100 125 150
-50 -25
0
25 50 75 100 125 150
Junction Temperature (°C)
Junction Temperature (°C)
Figure 59. Internal Current Limit vs. Temperature.
Figure 60. External Current Limit vs. Temperature with
RIL = 12 kΩ.
1.2
1.0
1.2
1.0
0.8
0.6
0.4
0.8
0.6
0.4
0.2
0
0.2
0
-50 -25
0
25 50 75 100 125 150
-50 -25
0
25 50 75 100 125 150
Junction Temperature (°C)
Junction Temperature (°C)
Figure 62. Under-Voltage Threshold vs. Temperature.
Figure 61. Overvoltage Threshold vs. Temperature.
M
12/04
43
TOP242-250
Typical Performance Characteristics (cont.)
6.0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
VX = 1.33 - IXx 0.66 kΩ
-200 µA ≤ IX ≤ -25 µA
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
0
0
100
200
300
400
-240
-180
-120
-60
0
EXTERNAL CURRENT LIMIT Pin Current (µA)
LINE-SENSE Pin Current (µA)
Figure 63a. LINE-SENSE Pin Voltage vs. Current.
Figure 63b. EXTERNAL CURRENT LIMIT Pin Voltage
vs. Current.
1.6
6
5
4
3
VM = 1.37 - IMx 1 kΩ
1.4
-200 µA ≤ IM ≤ -25 µA
1.2
1.0
0.8
0.6
0.4
0.2
0
2
See
Expanded
Version
1
0
-300 -250 -200 -150 -100 -50
0
-300 -200 -100
0
100 200 300 400 500
MULTI-FUNCTION Pin Current (µA)
MULTI-FUNCTION Pin Current (µA)
Figure 64b. MULTI-FUNCTION Pin Voltage vs. Current
(Expanded).
Figure 64a. MULTI-FUNCTION Pin Voltage vs. Current.
1.2
1.0
0.8
0.6
0.4
0.2
1.2
1.0
0.8
0.6
0.4
0.2
0
0
-50 -25
0
25 50 75 100 125 150
-50 -25
0
25 50 75 100 125 150
Junction Temperature (°C)
Junction Temperature (°C)
Figure 65. Control Current Out at 0% Duty Cycle
vs. Temperaure.
Figure 66. Max. Duty Cycle Reduction Onset Threshold
Current vs. Temperature.
M
44 12/04
TOP242-250
Typical Performance Characteristics (cont.)
6
5
2
VC = 5 V
1.6
1.2
4
Scaling Factors:
TOP250 1.17
3
TOP249 1.00
TOP248 0.83
0.8
0.4
0
2
1
TOP247 0.67
TOP246 0.50
TOP245 0.33
TOP244 0.25
TOP243 0.17
TOP242 0.08
TCASE = 25 °C
TCASE = 100 °C
0
0
20
40
60
80
100
0
2
4
6
8
10 12 14 16 18 20
DRAIN Voltage (V)
DRAIN Voltage (V)
Figure 67. Output Characteristics.
Figure 68. IC vs. DRAIN Voltage.
600
10000
Scaling Factors:
TOP250 1.17
500
TOP249 1.00
TOP248 0.83
Scaling Factors:
TOP247 0.67
400
1000
100
10
TOP250 1.17
TOP249 1.00
TOP248 0.83
TOP247 0.67
TOP246 0.50
TOP245 0.33
TOP244 0.25
TOP243 0.17
TOP242 0.08
TOP246 0.50
TOP245 0.33
TOP244 0.25
TOP243 0.17
TOP242 0.08
300
200
100
0
0
100 200 300 400 500 600
0
100 200 300 400 500 600
DRAIN Voltage (V)
Drain Voltage (V)
Figure 69. COSS vs. DRAIN Voltage.
Figure 70. DRAIN Capacitance Power.
1.2
1.0
0.8
0.6
0.4
0.2
0
-50
0
50
100
150
Junction Temperature (°C)
Figure 71. Remote OFF DRAIN Supply Current vs.
Temperature.
M
12/04
45
TOP242-250
PART ORDERING INFORMATION
TOPSwitch Product Family
GX Series Number
Package Identifier
G
P
Y
R
F
Plastic SMD-8B
Plastic DIP-8B
(TOP242-244 only)
(TOP242-246 only)
Plastic TO-220-7C
Plastic TO-263-7C (available only with TL option)
Plastic TO-262-7C
Lead Finish
Blank Standard (Sn Pb)
N
Pure Matte Tin (Pb-Free)
Tape & Reel and Other Options
Blank Standard Configurations
TL
Tape & Reel, (G Package: 1000 min., R Package: 750 min.)
TOP 242 G N - TL
M
46 12/04
TOP242-250
TO-220-7C
.165 (4.19)
.185 (4.70)
.390 (9.91)
.420 (10.67)
.045 (1.14)
.055 (1.40)
.146 (3.71)
.156 (3.96)
.108 (2.74) REF
.234 (5.94)
.261 (6.63)
+
.570 (14.48)
REF.
.461 (11.71)
.495 (12.57)
7° TYP.
.670 (17.02)
REF.
.860 (21.84)
.880 (22.35)
.080 (2.03)
.120 (3.05)
.068 (1.73) MIN
.024 (.61)
PIN 1 & 7
PIN 2 & 4
.040 (1.02)
.060 (1.52)
PIN 1
.010 (.25) M
.034 (.86)
.012 (.30)
.024 (.61)
.040 (1.02)
.060 (1.52)
.050 (1.27) BSC
.150 (3.81) BSC
.190 (4.83)
.210 (5.33)
.050 (1.27)
Notes:
.050 (1.27)
1. Controlling dimensions are inches. Millimeter
dimensions are shown in parentheses.
2. Pin numbers start with Pin 1, and continue from left
to right when viewed from the front.
3. Dimensions do not include mold flash or other
protrusions. Mold flash or protrusions shall not
exceed .006 (.15mm) on any side.
.050 (1.27)
.050 (1.27)
.180 (4.58)
.200 (5.08)
4. Minimum metal to metal spacing at the package
body for omitted pin locations is .068 in. (1.73 mm).
5. Position of terminals to be measured at a location
.25 (6.35) below the package body.
.100 (2.54)
PIN 1
PIN 7
.150 (3.81)
.150 (3.81)
6. All terminals are solder plated.
MOUNTING HOLE PATTERN
Y07C
PI-2644-122004
M
12/04
47
TOP242-250
DIP-8B
⊕D S .004 (.10)
Notes:
.137 (3.48)
MINIMUM
1. Package dimensions conform to JEDEC specification
MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP)
package with .300 inch row spacing.
-E-
2. Controlling dimensions are inches. Millimeter sizes are
shown in parentheses.
3. Dimensions shown do not include mold flash or other
protrusions. Mold flash or protrusions shall not exceed
.006 (.15) on any side.
.240 (6.10)
.260 (6.60)
4. Pin locations start with Pin 1, and continue counter-clock-
wise to Pin 8 when viewed from the top. The notch and/or
dimple are aids in locating Pin 1. Pin 6 is omitted.
5. Minimum metal to metal spacing at the package body for
the omitted lead location is .137 inch (3.48 mm).
6. Lead width measured at package body.
Pin 1
-D-
.367 (9.32)
.387 (9.83)
7. Lead spacing measured with the leads constrained to be
perpendicular to plane T.
.057 (1.45)
.068 (1.73)
(NOTE 6)
.125 (3.18)
.145 (3.68)
.015 (.38)
MINIMUM
-T-
SEATING
PLANE
.008 (.20)
.015 (.38)
.120 (3.05)
.140 (3.56)
.300 (7.62) BSC
(NOTE 7)
.300 (7.62)
.390 (9.91)
.100 (2.54) BSC
.048 (1.22)
.053 (1.35)
⊕T E D S .010 (.25) M
P08B
.014 (.36)
.022 (.56)
PI-2551-121504
SMD-8B
⊕ D S .004 (.10)
Notes:
.137 (3.48)
MINIMUM
1. Controlling dimensions are
inches. Millimeter sizes are
shown in parentheses.
-E-
2. Dimensions shown do not
include mold flash or other
protrusions. Mold flash or
protrusions shall not exceed
.006 (.15) on any side.
3. Pin locations start with Pin 1,
and continue counter-clock-
wise to Pin 8 when viewed
from the top. Pin 6 is omitted.
4. Minimum metal to metal
spacing at the package body
for the omitted lead location
is .137 inch (3.48 mm).
.372 (9.45)
.388 (9.86)
.010 (.25)
.240 (6.10)
.260 (6.60)
.420
⊕ E S
.046 .060 .060 .046
.080
Pin 1
Pin 1
-D-
.086
.186
.100 (2.54) (BSC)
5. Lead width measured at
package body.
6. D and E are referenced
datums on the package
body.
.286
.367 (9.32)
.387 (9.83)
Solder Pad Dimensions
.057 (1.45)
.068 (1.73)
(NOTE 5)
.125 (3.18)
.145 (3.68)
.004 (.10)
.032 (.81)
.037 (.94)
.048 (1.22)
.053 (1.35)
°
°
.009 (.23)
0 - 8
.036 (0.91)
.044 (1.12)
.004 (.10)
.012 (.30)
G08B
PI-2546-121504
M
48 12/04
TOP242-250
TO-263-7C
.390 (9.91)
.420 (10.67)
.045 (1.14)
.055 (1.40)
.245 (6.22)
MIN
.055 (1.40)
.066 (1.68)
.225 (5.72)
MIN
.326 (8.28)
.336 (8.53)
.580 (14.73)
.620 (15.75)
.000 (0.00)
.010 (0.25)
.208 (5.28)
Ref.
.090 (2.29)
.110 (2.79)
-A-
.010 (0.25)
0.68 (1.73)
MIN
.012 (0.30)
.024 (0.61)
LD #1
.024 (0.61)
.034 (0.86)
.100 (2.54)
REF
.050 (1.27)
°
°
0 - 8
.315 (8.00)
.165 (4.19)
.185 (4.70)
Solder Pad
Dimensions
.004 (0.10)
.380 (9.65)
Notes:
1. Package Outline Exclusive of Mold Flash & Metal Burr.
2. Package Outline Inclusive of Plating Thickness.
3. Foot Length Measured at Intercept Point Between
Datum A Lead Surface.
4. Controlling Dimensions are in Inches. Millimeter
Dimensions are shown in Parentheses.
.638 (16.21)
.128 (3.25)
R07C
PI-2664-122004
.050 (1.27)
.038 (0.97)
5. Minimum metal to metal spacing at the package body
for the omitted pin locations is .068 in. (1.73 mm).
M
12/04
49
TOP242-250
TO-262-7C
.045 (1.14)
.055 (1.40)
.390 (9.91)
.420 (10.67)
.165 (4.17)
.185 (4.70)
.055 (1.40)
.066 (1.68)
.326 (8.28)
.336 (8.53)
.495 (12.56)
REF.
7° TYP.
.595 (15.10)
REF.
.795 (20.18)
REF.
.080 (2.03)
.120 (3.05)
PIN 1 & 7
PIN 2 & 4
.068 (1.73) MIN
.024 (.61)
.040 (1.02)
.060 (1.52)
PIN 1
.010 (.25) M
.034 (.86)
.012 (.30)
.024 (.61)
.040 (1.06)
.060 (1.52)
.050 (1.27) BSC
.150 (3.81) BSC
.190 (4.83)
.210 (5.33)
.050 (1.27)
Notes:
.050 (1.27)
1. Controlling dimensions are inches. Millimeter
dimensions are shown in parentheses.
2. Pin numbers start with Pin 1, and continue
from left to right when viewed from the front.
3. Dimensions do not include mold flash or
other protrusions. Mold flash or protrusions
shall not exceed .006 (.15mm) on any side.
4. Minimum metal to metal spacing at the pack-
age body for omitted pin locations is .068
inch (1.73 mm).
.050 (1.27)
.050 (1.27)
.180 (4.58)
.200 (5.08)
.100 (2.54)
PIN 1
PIN 7
.150 (3.81)
5. Position of terminals to be measured at a
location .25 (6.35) below the package body.
6. All terminals are solder plated.
.150 (3.81)
MOUNTING HOLE PATTERN
F07C
PI-2757-122004
M
50 12/04
TOP242-250
Revision Notes
Date
11/00
7/01
D
E
-
1) Added R package (D2PAK).
2) Corrected abbreviations (s = seconds).
3) Corrected x-axis units in Figure 11 (µA).
4) Added missing external current limit resistor in Figure 25 (RIL).
5) Corrected spelling.
6) Added caption for Table 4.
7) Corrected Breakdown Voltage parameter condition (TJ = 25 °C).
8) Corrected font sizes in figures.
9) Figure 40 replaced.
10) Corrected schematic component values in Figure 44.
F
1) Corrected Power Table value.
9/01
1/02
G
1) Added TOP250 device and F package (TO-262).
2) Added R package Thermal Impedance parameters and adjusted Output Power values in Table 1.
3) Adjusted Off-State Current value.
H
I
1) Added note to parameter table for Breakdown Voltage measurement.
2) Miscellaneous text corrections.
9/02
4/03
1) Updated P, Y, R and F package information.
2) Revised thermal impedances (θJA) for all package types.
3) Expanded Maximum Duty Cycle and deleted Maximum Duty Cycle Reduction Slope parameters.
4) Corrected DIP-8B and SMD-8B Package Drawings.
J
1) Added TOP245P.
2) Miscellaneous text corrections.
8/03
9/03
K
1) Corrected typographic errors in Figures 4, 6, 20, 28 and 34; and in MULIT-FUNCTION (M) Pin
Operation section.
L
1) Added TOP246P.
3/04
M
1) Added lead-free ordering information.
12/04
M
12/04
51
TOP242-250
For the latest updates, visit our website: www.powerint.com
Power Integrations may make changes to its products at any time. Power Integrations has no liability arising from your use of any information, device or circuit
described herein nor does it convey any license under its patent rights or the rights of others. POWER INTEGRATIONS MAKES NO WARRANTIES HEREIN
AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS.
PATENT INFORMATION
The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S.
and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrationsʼ patents
may be found at www.powerint.com.
LIFE SUPPORT POLICY
POWER INTEGRATIONSʼ PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF POWER INTEGRATIONS. As used herein:
1. Life support devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when
properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user.
2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or effectiveness.
The PI logo, TOPSwitch, TinySwitch, LinkSwitch, DPA-Switch and EcoSmart are registered trademarks of
Power Integrations. PI Expert and PI FACTS are trademarks of Power Integrations. ©Copyright 2004, Power Integrations
Power Integrations Worldwide Sales Support Locations
JAPAN
WORLD HEADQUARTERS
5245 Hellyer Avenue
San Jose, CA 95138, USA.
Main: +1-408-414-9200
Customer Service:
Phone: +1-408-414-9665
Fax: +1-408-414-9765
e-mail: usasales@powerint.com
GERMANY
Rueckertstrasse 3
D-80336, Muenchen, Germany
Phone: +49-895-527-3910
Fax: +49-895-527-3920
e-mail: eurosales@powerint.com
TAIWAN
5F-1, No. 316, Nei Hu Rd., Sec. 1
Nei Hu Dist.
Taipei, Taiwan 114, R.O.C.
Phone: +886-2-2659-4570
Fax: +886-2-2659-4550
e-mail: taiwansales@powerint.com
Keihin-Tatemono 1st Bldg.
12-20 Shin-Yokohama
2-Chome,
Kohoku-ku, Yokohama-shi,
Kanagawa 222-0033, Japan
Phone: +81-45-471-1021
Fax: +81-45-471-3717
e-mail: japansales@powerint.com
INDIA (TECHNICAL SUPPORT)
261/A, Ground Floor
7th Main, 17th Cross,
UK (EUROPE & AFRICA
HEADQUARTERS)
1st Floor, St. Jamesʼs House
East Street
Farnham, Surrey GU9 7TJ
United Kingdom
Phone: +44 (0) 1252-730-140
Fax: +44 (0) 1252-727-689
e-mail: eurosales@powerint.com
CHINA (SHANGHAI)
Rm 807-808A, Pacheer
Commercial Centre
555 Nanjing West Road
Shanghai, 200041, China
Phone: +86-21-6215-5548
Fax: +86-21-6215-2468
e-mail: chinasales@powerint.com
KOREA
RM 602, 6th Floor
Sadashivanagar
Bangalore, India 560080
Phone: +91-80-5113-8020
Fax: +91-80-5113-8023
e-mail: indiasales@powerint.com
Korea City Air Terminal B/D, 159-6,
Samsung-Dong, Kangnam-Gu,
Seoul, Korea
Phone: +82-2-2016-6610
Fax: +82-2-2016-6630
e-mail: koreasales@powerint.com
ITALY
Via Vittorio Veneto 12,
Bresso
CHINA (SHENZHEN)
APPLICATIONS HOTLINE
SINGAPORE
Rm 2206-2207, Block A,
Milano, 20091, Italy
World Wide +1-408-414-9660
51 Newton Road
Electronics Science & Technology Bldg., Phone: +39-028-928-6001
#15-08/10 Goldhill Plaza
Singapore, 308900
2070 Shennan Zhong Road,
Shenzhen, Guangdong,
Fax: +39-028-928-6009
e-mail: eurosales@powerint.com
APPLICATIONS FAX
World Wide +1-408-414-9760
Phone: +65-6358-2160
Fax: +65-6358-2015
e-mail: singaporesales@powerint.com
China, 518031
Phone: +86-755-8379-3243
Fax: +86-755-8379-5828
e-mail: chinasales@powerint.com
M
52 12/04
相关型号：
TOP243YN-
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP243YN-TL
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244
Extended Power, Design Flexible EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244F
TOPSwitch -GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244F-
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244F-TL
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244FN
IC OFFLINE SWIT UVLO HV TO262Warning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244FN-
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244FN-TL
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244G
TOPSwitch -GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244G-
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
TOP244G-TL
TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line SwitcherWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
POWERINT
©2020 ICPDF网 联系我们和版权申明