HIP5061DS [INTERSIL]
7A, High Efficiency Current Mode Controlled PWM Regulator; 7A ,高效电流模式控制PWM稳压器![HIP5061DS](http://pdffile.icpdf.com/pdf1/p00077/img/icpdf/HIP5061_405431_icpdf.jpg)
型号: | HIP5061DS |
厂家: | ![]() |
描述: | 7A, High Efficiency Current Mode Controlled PWM Regulator |
文件: | 总20页 (文件大小:161K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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HIP5061
7A, High Efficiency Current
Mode Controlled PWM Regulator
April 1994
Features
Description
• Single Chip Current Mode Control IC
• 60V, On-Chip DMOS Power Transistor
• Thermal Protection
The HIP5061 is a complete power control IC, incorporating
both the high power DMOS transistor, CMOS logic and low
level analog circuitry on the same Intelligent Power IC. The
standard “Boost”, “Buck-Boost”, “Cuk”, “Forward”, “Flyback”
and the “SEPIC” (Single-Ended Primary Inductance Con-
verter) power supply topologies may be implemented with
this single control IC.
• Over-Current Protection
• 250kHz Operation
Over-temperature and rapid short-circuit recovery circuitry is
incorporated within the IC. These protection circuits disable
the drive to the power transistor to protect the transistor and
insure rapid restarting of the supply after the short circuit is
removed.
• Output Rise and Fall Times - 10ns
• On-Chip Reference Voltage - 5.1V
• Slope Compensation
• VDD Clamp Allows 10.8V to 60V Supply
As a result of the power DMOS transistors current (7A at 30%
duty cycle, 5A DC) and 60V capability, supplies with output
power over 50W are possible.
• Supply Current Does Not Increase When Power
Device is On
Applications
Ordering Information
• Distributed / Board Mounted Power Supplies
• DC - DC Converter Modules
• Voltage Inverters
PART
NUMBER
TEMPERATURE
RANGE
PACKAGE
o
o
HIP5061DS
0 C to +85 C
7 Lead Staggered “Gullwing” SIP
• Small Uninterruptable Power Supplies
• Cascode Switching for Off Line SMPS
Simplified Functional Diagram
Pinout
HIP5061 (SIP)
VIN
TOP VIEW
VOUT
PIN 7 VDD
PIN 6 VG
PIN 5 DRAIN
PIN 4 SOURCE
PIN 3 FB
PIN 2 VC
PIN 1 GND
VDD
VDD CLAMP
VG
DRAIN
HIP5061
CLOCK
DO NOT
USE
SOURCE
(TAB)
GATE
DRIVER
CONTROL
LOGIC
SOURCE
(TAB)
VC
FB
OVER
TEMP
AMP
V/I
2.5V
UNDER
VOLTAGE
SLOPE
COMPENSATION
5.1V
REFERENCE
GND
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
File Number 3390.2
407-727-9207 | Copyright © Intersil Corporation 1999
7-53
Specifications HIP5061
Absolute Maximum Ratings (Note 1)
Thermal Information
DC Supply Voltage, V . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 16V Thermal Resistance
θ
JC
2 C/W
DD
o
DC Supply Current, I
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .105mA
Plastic SIP Package . . . . . . . . . . . . . . . . . . . . . . . .
DD
o
DMOS Drain Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 60V Maximum Package Power Dissipation at +85 C
Average DMOS Drain Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 5A
DMOS Source Voltage, V , TAB . . . . . . . . . . . . -0.1V to 0.1V
(Depends Upon Mounting, Heat Sink and Application) . . . . . 10W
Max. Junction Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . +105 C
o
SOURCE
DC Supply Voltage, V . . . . . . . . . . . . . . . . . . . .-0.3V to V + 0.3V
(Controlled By Thermal Shutdown Circuit)
G
DD
o
Compensation Pin Current, I
. . . . . . . . . . . . . . . . . -5mA to 35mA Lead Temperature (Soldering 10s) . . . . . . . . . . . . . . . . . . . . +265 C
VC
Voltage at All Other Pins. . . . . . . . . . . . . . . . . . .-0.3V to V + 0.3V
DD
o
o
Operating Junction Temperature Range. . . . . . . . . . .0 C to +105 C
o
o
Storage Temperature Range . . . . . . . . . . . . . . . . . -55 C to +150 C
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 2 - 2KV
Single Pulse Avalanche Energy Rating, µs (Note 2) . . . EAS 100mJ
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
o
o
Electrical Specifications
V
= V =12V, V = 5V, V = 5.1V, SOURCE = GND = DRAIN = 0V, T = 0 C to +105 C,
DD
G
C
FB
J
Unless Otherwise Specified
SYMBOL
PARAMETER TEST CONDITIONS
MIN
TYP
MAX
UNITS
DEVICE PARAMETERS
I
Quiescent Supply Current
V
V
= V = 13.2V, V = 0V,
= 4V
6
12
18
mA
DD
DD
FB
G
C
I
Operating Supply Current
Quiescent Current to Gate Driver
Operating Current to Gate Driver
Clamp Voltage
V
V
V
= V = 13.2V, V = 8.5V, V = 4V
-
-
24
0
31
10
2
mA
µA
mA
V
DD
DD
DD
G
C
FB
IV
IV
= V = 13.2V, V = 0V
G
G
C
= 3V
-
1
G
C
V
I
I
= 100mA
13.3
5.0
14
5.1
15
5.2
DDC
DD
VC
V
Reference Voltage
= 0µA, V = V
FB
V
REF
C
AMPLIFIERS
|I
|
Input Current
V
= V
REF
-
-0.85
30
0.5
43
µA
FB
FB
g
(V
)
V
Transconductance
/I / = 500µA, Note 3
20
mS
m
FB
FB
VC
I
/(V - V
)
REF
VC
FB
IV
IV
Maximum Source Current
Maximum Sink Current
Voltage Gain
V
V
= 4.6V
= 5.6V
-4
1
-1.8
1.8
50
-1
4
mA
mA
dB
V
CMAX
CMAX
FB
FB
A
/I / = 500µA, Note 3
44
5.4
-
OL
VC
V
Short Circuit Recovery Compara-
tor Rising Threshold Voltage
6.6
8.9
CMAX
V
Short Circuit Recovery
Comparator Hysteresis Voltage
0.7
0
1.1
10
1.8
25
V
CHYS
IVC
V
Over-Voltage Current
V
= V = 10.8V, V = V
CMAX
mA
OVER
C
DD
G
C
CLOCK
fq
Internal Clock Frequency
210
250
290
kHz
DMOS TRANSISTOR
rDS
Drain-Source On-State
Resistance
I
= 5A, V = V = 10.8V
-
-
0.15
-
0.22
0.33
Ω
Ω
(ON)
DRAIN
DD
G
o
T = +25 C
J
rDS
Drain-Source On-State
Resistance
I
= 5A, V = V = 10.8V
(ON)
DRAIN DD G
o
T = +105 C
J
I
Drain-Source Leakage Current
V
V
= 60V
-
-
0.5
-
10
5
µA
DSS
DRAIN
DRAIN
I
Average Drain Short Circuit
Current
= 5V, Note 4
A
DSH
C
DRAIN Capacitance
Note 4
-
200
-
pF
DRAIN
7-54
Specifications HIP5061
o
o
Electrical Specifications
V
= V =12V, V = 5V, V = 5.1V, SOURCE = GND = DRAIN = 0V, T = 0 C to +105 C,
DD
G
C
FB
J
Unless Otherwise Specified (Continued)
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
CURRENT CONTROLLED PWM
g (V )
∆I
/∆V
C
Note 3
1.4
2.4
2.2
2.8
3.0
3.1
A/V
V
m
C
DRAIN, PEAK
V/I
Voltage to Current Converter Ref-
erence Voltage
I
= 0.25A, Note 3
REF
DRAIN
t
Current Comparator Blanking
Time
Note 3
40
100
175
ns
BT
t
Minimum DMOS “ON” Time
Minimum DMOS “OFF” Time
Note 3
Note 3
Note 3
60
40
-
150
125
100
250
200
250
ns
ns
ONMIN
t
OFFMIN
MinCI
Minimum Controllable DMOS
Peak Current
mA
MaxCI
MaxCI
Maximum Controllable DMOS
Peak Current
Duty Cycle = 6% to 30%, Note 3
Duty Cycle = 30% to 96%, Note 3
7
5
9.5
8
12
12
A
A
Maximum Controllable DMOS
Peak Current
CURRENT COMPENSATION RAMP
∆I/∆t
Compensation Ramp Rate
Compensation Ramp Delay
∆I
/∆Time, Note 3
-1.4
1.3
-0.85
1.5
-0.45
1.8
A/µs
µs
DRAIN, PEAK
t
Note 3
RD
START-UP
V
Rising V Threshold Voltage
V
V
= 4V
= 4V
9.3
0.3
1.0
10.3
0.45
1.5
10.8
0.6
V
V
V
DDMIN
DDHYS
DD
FB
FB
V
Power-On Hysteresis
V
Enable Comparator Threshold
Voltage
2.0
CEN
R
Power-Up Resistance
4V < V < 10.8V, V = 0.8V
50
500
3000
Ω
VC
DD
C
THERMAL MONITOR
o
T
Substrate Temperature for
Thermal Monitor to Trip
Note 4
Note 4
105
-
-
145
-
C
J
o
T
Temperature Hysteresis
5
C
JHY
NOTES:
1. All Voltages relative to pin 1, GND.
o
2. V = 10V, Starting T = +25 C, L = 4mH, I
= 7A.
D
J
PEAK
3. Test is performed at wafer level only.
4. Determined by design, not a measured parameter.
TABLE 1. CONDITIONS FOR UNCLAMPED ENERGY CIRCUIT
7
1
L
I
L
+
V
(V)
(PEAK AMPS)
L (mH)
40
EAS (mJ)
550
D
HIP5061
IL
VD
-
10
5
7
VARY tP TO OBTAIN
REQUIRED PEAK IL
10
6
4TZ
120
10
12.5
0.33
0.14
18
12V
tP
6
12
NOTE: Device Selected to Obtain Peak Current without Clocking
FIGURE 1. UNCLAMPED ENERGY TEST CIRCUIT
7-55
HIP5061
V
CHYS, VCMAX Hysteresis - The voltage on VC that causes
Definitions of Electrical Specifications
the NMOS transistor to turnoff if it had been turned on by VC
exceeding VCMAX. At this voltage the current out of the Voltage-
to-Current Converter is at roughly three quarters of full-scale.
Refer to the Functional Block Diagram of Figure 1 for loca-
tions of functional blocks and devices.
Device Parameters
IVCOVER, VC Over-Voltage Current - The current drawn
through the VC pin after the NMOS transistor is turned on
due to excessive voltage on VC. The NMOS transistor con-
nected to the VC pin draws more than enough current to
overcome the full scale source current of the Error Amplifier.
IDD, Quiescent Supply Current - Supply current with the
chip disabled. The Clock, Error Amplifier, Voltage-to-Current
Converter, and Current Ramp circuits draw only quiescent
current. The supply voltage must be kept lower than the
turn-on voltage of the VDD clamp or else the supply current
increases dramatically.
Clock
fq, Frequency - The frequency of the DC/DC converter. The
Clock actually runs faster than this value so that various con-
trol signals can be internally generated.
IDD, Operating Supply Current - Supply current with the
chip enabled. The Error Amplifier is drawing its maximum
current because VFB is less than its reference voltage. The
voltage-to-current amplifier is drawing its maximum because
VC is at its maximum. The ramp circuit is drawing its maxi-
mum because it is not being disabled by the DMOS transis-
tor turning off.
DMOS Transistor
rDS(ON), “On” Resistance - Resistance from DMOS transis-
tor Drain to Source at maximum drain current and minimum
Gate Driver voltage, VG.
IVG, Quiescent Gate Driver Current - Gate Drivers supply
current with the IC disabled. The Gate Driver is not toggling
and so it draws only leakage current.
IDSS, Leakage Current - Current through DMOS transistor
at the Maximum Rated Voltage.
Current Controlled PWM
IVG, Operating Gate Driver Current - Gate Drivers supply
current with the IC enabled. The DMOS transistor drain is
loaded with a large resistor tied to 60V so that it is swinging
from 0V to 60V during each cycle.
gm(VC), Transconductance - The change in the DMOS tran-
sistor peak drain current divided by the change in voltage on
VC. When analyzing DC/DC converters the DMOS transistor
and the inductor tied to the drain are sometimes modelled as
a voltage-controlled current source and this parameter is the
gain of the voltage-controlled current source.
VDDC, VDD Clamp - VDD voltage at the maximum allowed
current through the VDD Clamp.
VREF, Reference Voltage - The voltage on FB that sets the
current on VC to zero. This is the reference voltage for the
DC/DC converter.
V/IREF, Current Control Threshold - The voltage on VC
that causes the DMOS transistor to shut off at the minimum
controllable current. This voltage is greater than the Enable
Comparator Threshold (VCEN) so that as VC rises the IC
does not jump from the disabled state to the DMOS transis-
tor conducting a large current.
Amplifiers
|IFB|, Input Current - Current through FB pin when it is at its
normal operating voltage. This current must be considered
when connecting the output of a DC/DC convertor to the FB
pin via a resistor divider.
t
BT, Blanking Time - At the beginning of each cycle there is
a blanking time that the DMOS transistor turns-on and stays-
on no matter how high drain the current. This blanking time
permits ringing in the external parasitic capacitances and
inductances to dampen and for the charging of the reverse
bias on the rectifier diode.
gm(VFB), Transconductance - The change in current
through the VC pin divided by the change in voltage on FB.
The gm times the resistance between VC and ground gives
the voltage gain of the Error Amplifier.
t
ONMIN, Minimum DMOS Transistor “On” Time - The mini-
IVCMAX, Maximum Source Current - The current on VC
when FB is more than a few hundred millivolts less than
mum on-time for the DMOS transistor where small changes
in the VC voltage make predictable changes in the DMOS
transistor peak current. Converters should be designed to
avoid requiring pulse widths less than the minimum on time.
VREF
.
IVCMAX, Maximum Sink Current - The current on VC when
FB is more than a few hundred millivolts more than VREF
.
t
OFFMIN, Minimum DMOS Transistor “Off” Time - The min-
imum off-time for the DMOS transistor that allows enough time
for the IC to get ready for the next cycle. Converters should be
designed to avoid requiring pulse widths so large that the mini-
mum off time is violated. (However, zero off time is allowed, that
is, the DMOS transistor can stay on from one cycle to the next.)
AOL, Voltage Gain - Change in the voltage on VC divided by
the change in voltage on FB. There is no resistive load on
VC. This is the voltage gain of the error amplifier when gm
times load resistance is larger than this gain.
VCMAX, VC Rising Threshold - The voltage on VC that
causes the Voltage-to-Current Amplifier to reach full-scale.
When VC reaches this voltage, the VC NMOS transistor (tran-
sistor with its drain connected to the VC pin in the Functional
Block Diagram of Figure 2) turns on and tries to lower the volt-
age on VC.
MinCI, Minimum Controllable Current - When the voltage
on VC is below V/IREF, the peak current for the DMOS tran-
sistor is too small for the Current Comparator to operate reli-
ably. Converters should be designed to avoid operating the
DMOS transistor at this low current.
7-56
HIP5061
MaxCI, Maximum Controllable Current - The peak current
VCEN, Enable Comparator Threshold Voltage - The mini-
for the DMOS transistor when the Voltage-to-Current Con- mum voltage on VC needed to enable the IC. The IC can be
verter is at its full scale output. The DMOS transistor current shutdown from an open-collector logic gate by pulling down
may exceed this value during the blanking time so proper the VC pin to GND.
precautions should be taken. This parameter is unchanged
for the first 3/8 of the cycle and then decreases linearly with
time because of the Current Ramp becoming active.
RVC, Power - Up Resistance - When VDD is below VDDMIN
,
the NMOS transistor connected to the VC pin is turned on to
make sure the VC node is low. Thus the voltage on VC can
gradually build up as will the trip current on the DMOS tran-
sistor. This is the only form of “soft start” included on the IC.
The resistance is measured between the VC and GND pins.
Current Compensation Ramp
∆I/∆t, Compensation Ramp Rate - At a given voltage on VC
the DMOS transistor will turn off at some current that stays
constant for about the first 1.5µs of the cycle. After 1.5µs, the Thermal Monitor
turnoff current starts to linearly decrease. This parameter
TJ , Rising Temperature Threshold - The IC temperature
that causes the IC to disable itself so as to prevent damage.
RD, Compensation Ramp Delay - The time into each cycle Proper heat-sinking is required to avoid over-temperature
specifies the change in the DMOS transistor turnoff current.
t
that the compensation ramp turns on. The Current Compen- conditions, especially during start-up when the DMOS tran-
sation Ramp, used for Slope Compensation, is developed by sistor may stay on for a long time if an external soft-start cir-
the Current Ramp block shown in the FUNCTIONAL BLOCK cuit is not added.
DIAGRAM of Figure 2.
T
JHY, Temperature Hysteresis - The IC must cool down
Start-Up
this much after it is disabled by being too hot before it can
resume normal operation.
VDDMIN, Rising VDD Threshold Voltage - The minimum
voltage on VDD needed to enable the IC.
VDDHYS, Power - On Hysteresis Voltage - The difference
between the voltage on VDD that enables the IC and the volt-
age that disables the IC.
VDD
7
VG
6
VDD
CLAMP
RAMP RESET
RAMP ENABLE
BIAS
CIRCUITS
CURRENT
RAMP
BAND GAP
REFERENCE
REGULATOR
DRAIN
5
GND
1
VDD
CONTROL
LOGIC
GATE
DRIVER
-
CLOCK
VREF = 5.1V
10.3V
+
VDD MONITOR
UNDER VOLTAGE
LOCK OUT
VC
2
+
ENABLE
ENABLE
TAB
-
ERROR
AMP
DISABLE
100ns
CURRENT
MONITORING
THERMAL
MONITOR
BLANKING
1.5V
SOURCE
VOLTAGE TO
CURRENT
VDD
FB
3
CURRENT SAMPLE
-
CONVERTER
-
ERROR
AMP
+
+
-
360Ω
360Ω
CURRENT
COMPARE
INTERNAL LEAD
ERROR CURRENT
INDUCTANCE
2KΩ
2KΩ
AND RESISTANCE
+
LIGHT LOAD
COMPARATOR
SOURCE
4
5.1V
VREF
+
SHORT
CIRCUIT
HIP5061
-
7.0V
FIGURE 2. FUNCTIONAL BLOCK DIAGRAM OF THE HIP5061
7-57
HIP5061
Pin Description
TERMINAL
NUMBER
DESIGNATION
DESCRIPTION
1
2
GND
This is the analog ground terminal of the IC.
V
The output of the transconductance amplifier appears at this terminal. Input to the internal
voltage to current converter also appears at this node. Transconductance amplifier gain
C
and loop response are set at this terminal. When the V terminal voltage is below the
DD
starting voltage, V
, this terminal is held low. When the voltage at this terminal
DDMIN
exceeds V
, 7V typical, implying an over-current condition, a typical 10mA current,
CMAX
I
pulls this terminal towards ground. This current remains “ON” until the voltage on
VCOVER
the V terminal falls by V
, typically 1.1V, below the upper threshold, V
. When the
C
CHYS
CMAX
voltage on this terminal falls below V
, typically 1.5V, the IC is disabled.
CEN
3
4
FB
Feedback from the regulator output is applied to this terminal. This terminal is the input to
the transconductance amplifier. The amplifier compares the internal 5.1V reference and
the feedback signal from the regulator output.
SOURCE
DRAIN
The terminal, labeled TAB, has a connection to this terminal, but because of the long lead
length and resulting high inductance of this terminal, it should not be used as a means of
bypassing. Therefore, this terminal is labeled “Do Not Use.”
5
6
Connection to the Drain of the internal power DMOS transistor is made at this terminal.
V
Gate drive supply voltage is provided at this terminal. A 10Ω to 150Ω resistor connected
G
between this terminal and the V terminal provides decoupling and the supply voltage
DD
for the gate drivers.
7
V
External supply input to the IC. A nominal 14V shunt regulator is connected between this
terminal and the TAB. A series resistor should be connected to this terminal from the
external voltage source to supply a minimum current of 33mA and a maximum current of
105mA under the worst cast supply voltage. The series resistor is not required if the
supply voltage is 12V, ±10%.
DD
TAB
SOURCE
This is the internal power DMOS transistor Source terminal. It should be used as the
ground return for the V bypass capacitor. In addition high frequency bypassing for both
DD
the regulator output load voltage and supply input voltage should be returned to this
terminal.
For more information refer to Application Notes AN9208, AN9212, AN9323.
Foot Print For Soldering
0.523
LIMIT OF SOLDER MASK
FOR HEADER
0.120
OPTIONAL Ø 0.151
0.050 TYP
0.212
0.424
0.050 TYP
0.080 TYP
0.480
0.575
0.675
TO-220 STAGGERED GULL WING SIP
7-58
HIP5061
Typical Performance Curves
26
24
20
18
16
14
12
10
8
VFB = VC = 0V, TA = +25oC
OPERATING CURRENT, VDD = VG = 13.2V, VC = 8.5V, VFB = 4V
22
20
18
16
14
QUIESCENT CURRENT, VDD = VG = 13.2V, VC = 0V, VFB = 4V
6
12
4
10
8
2
0
6
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14
0
10
20
30
40
50
60
70
80
90
100
AMBIENT TEMPERATURE (oC)
VDD (V)
FIGURE 3. TYPICAL SUPPLY CURRENT vs TEMPERATURE
FIGURE 4. TYPICAL SUPPLY CURRENT vs SUPPLY VOLTAGE
26
1.2
1.1
1.0
0.9
24
VDD = 12V, VFB = 6V
22
20
18
16
14
12
10
TA = 0oC
TA = +105oC
0.8
VDD = VG = 12V, VFB = 5.1V, VC = 5V
0.7
0.6
0.5
0.4
0.3
0.2
8
6
4
0
10
20
30
40
50
60
70
80
90 100
0
1
2
3
4
5
6
7
8
9
10 11 12
AMBIENT TEMPERATURE (oC)
VOLTAGE AT VC PIN (V)
FIGURE 5. TYPICAL GATE DRIVER OPERATING
CURRENT vs TEMPERATURE
FIGURE 6. TYPICAL SUPPLY CURRENT vs VOLTAGE
o
o
AT PIN V FOR 0 C AND +105 C
C
15.0
14.8
14.6
5.20
5.18
5.16
5.14
5.12
5.10
5.08
5.06
5.04
5.02
5.00
IDD = 100mA
14.4
VDD = VG = 12V, IVC = 0µA, VC = VFB
14.2
14.0
13.8
13.6
13.4
13.2
13.0
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 7. TYPICAL CLAMP VOLTAGE vs TEMPERATURE
FIGURE 8. TYPICAL REFERENCE VOLTAGE vs
TEMPERATURE
7-59
HIP5061
Typical Performance Curves (Continued)
5.20
-50
-55
-60
-65
-70
-75
-80
-85
-90
-95
-100
5.18
IVC = 0mA, VC = VFB
5.16
VDD = VG = 12V, VC = 5V, VFB = VREF
5.14
TA = +105oC
5.12
5.10
TA = 0oC
5.08
5.06
5.04
5.02
5.00
10.8
11.2
11.6
12.0
12.4
DD (V)
12.8
13.2
13.6 14.0
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
V
FIGURE 9. TYPICAL REFERENCE VOLTAGE vs SUPPLY
FIGURE 10. TYPICAL INPUT CURRENT TO FB PIN vs
TEMPERATURE
o
o
VOLTAGE FOR 0 C AND +105 C
0.5
36
35
0.4
0.3
0.2
0.1
0
34
VDD = VG = 12V, IVC = 500µA
33
32
31
30
29
28
27
26
25
24
23
22
VDD = VG = 12V, VC = 4V, TA = +25oC
-0.1
-0.2
-0.3
-0.4
-0.5
-1
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14
0
10
20
30
40
50
60
70
80
90 100
VOLTAGE ON FB PIN (V)
AMBIENT TEMPERATURE (oC)
FIGURE 11. TYPICAL INPUT CURRENT TO FB PIN vs V
FIGURE 12. TYPICAL ERROR AMPLIFIER
FB
TRANSCONDUCTANCE vs TEMPERATURE
2.5
2.0
2.5
2.0
VDD = VG = 12V, VC = 4V, TA = +25oC
1.5
SINKING CURRENT, VFB = 5.6V
1.5
1.0
0.5
1.0
0.5
VDD = VG = 12V, VC = 5V
0.0
0.0
-0.5
-0.5
-1.0
-1.5
-2.0
-1.0
-1.5
-2.0
-2.5
SOURCING CURRENT, VFB = 4.6V
-2.5
0
10
20
30
40
50
60
70
80
90 100
-175-150-125-100 -75 -50 -25
0
25 50 75 100 125 150 175
VOLTAGE ON FB PIN (mV) CENTERED AROUND 5.1V
AMBIENT TEMPERATURE (oC)
FIGURE 14. TYPICAL ERROR AMPLIFIER SINKING AND
SOURCING CURRENT vs TEMPERATURE
FIGURE 13. TYPICAL V PIN CURRENT IV PIN vs
C
C
VOLTAGE ON FB PIN (SHOWS ERROR
AMPLIFIER TRANSCONDUCTANCE)
7-60
HIP5061
Typical Performance Curves (Continued)
2.5
12
VDD = VG = 12V, VC = 4V, TA = +25oC
2.0
VDD = 9V (UNDER VOLTAGE CONDITION)
TA = 0oC
TA = +105oC
10
8
1.5
1.0
0.5
0.0
-0.5
6
4
2
-1.0
-1.5
-2.0
-2.5
0
0
1
2
3
4
5
6
7
8
9
-1
0
1
2
3
4
5
6
7
8
9
10 11 12 13
VOLTAGE ON VC PIN (V)
VOLTAGE ON FB PIN (V)
FIGURE 15. TYPICAL V PIN CURRENT vs
FIGURE 16. TYPICAL V PIN CURRENT vs VOLTAGE ON
C
C
o
o
VOLTAGE ON FB PIN
V PIN FOR 0 C AND +105 C
C
16
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
VDD = 12V, TA = +25oC
VCMAX
14
FB = 6V
FB = 4V
12
10
8
VDD = VG = 12V
6
4
FB = 6V
2
VCHYS
0
FB = 4V
-2
-4
0
10
20
30
40
50
60
70
80
90 100
0
1
2
3
4
5
6
7
8
9
10 11 12
AMBIENT TEMPERATURE (oC)
VOLTAGE ON VC PIN (V)
FIGURE 17. TYPICAL V PIN CURRENT vs VOLTAGE ON V PIN
FIGURE 18. TYPICAL SHORT CIRCUIT COMPARATOR
THRESHOLD VOLTAGE vs TEMPERATURE
C
C
FOR VOLTAGES ABOVE AND BELOW V
REF
11.0
10.5
10.0
9.5
3.0
2.5
VDD = VG = 10.8V, VC = VCMAX
VDD = VG = 12V, VFB = 5.1V
2.0
1.5
1.0
9.0
0.5
0.0
8.5
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0
8.0
7.5
7.0
6.5
6.0
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 19. TYPICAL OVER-VOLTAGE CURRENT vs
TEMPERATURE
FIGURE 20. TYPICAL CLOCK FREQUENCY PERCENT
CHANGE vs TEMPERATURE
7-61
HIP5061
Typical Performance Curves (Continued)
3.0
0.30
0.25
0.20
0.15
0.10
0.05
0.00
VDD = VG = 12V, VFB = 5.1V
2.5
2.0
1.5
TA = +100oC
VDD = VG = 10.8V, IDRAIN = 5A
1.0
TA = 0oC
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0
10.8
11.2
11.6
12.0
12.4
12.8
13.2
13.6
14.0
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
V
DD (V)
FIGURE21. TYPICALCLOCKFREQUENCYPERCENTCHANGE
FIGURE 22. TYPICAL DMOS TRANSISTOR DRAIN TO SOURCE
RESISTANCE vs TEMPERATURE
o
o
vs SUPPLY VOLTAGE V AT 0 C AND +100 C
DD
0.30
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
0.12
0.10
0.50
0.45
VDD = VG = 10.8V, VFB = 5.1V
TA = +100oC
VDD = 60V
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
TA = 0oC
0
10
20
30
40
50
60
70
80
90 100
0
1
2
3
4
5
6
7
AMBIENT TEMPERATURE (oC)
DMOS TRANSISTOR DRAIN CURRENT (A)
FIGURE 23. TYPICAL DMOS TRANSISTOR DRAIN TO SOURCE
FIGURE 24. TYPICAL DMOS TRANSISTOR DRAIN TO SOURCE
LEAKAGE CURRENT vs TEMPERATURE
RESISTANCE vs DRAIN CURRENT I
AT
DRAIN
o
o
0 C AND +100 C
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
2.90
VDD = VG = 12V
VDD = VG = 12V, IDRAIN = 0.25A
2.88
2.86
2.84
2.82
2.80
2.78
2.76
2.74
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 25. TYPICAL TRANSCONDUCTANCE FROM V PIN TO
FIGURE 26. TYPICAL VOLTAGE TO CURRENT CONVERTER
REFERENCE VOLTAGE vs TEMPERATURE
C
DMOS TRANSISTOR DRAIN (PEAK CURRENT)
vs TEMPERATURE
7-62
HIP5061
Typical Performance Curves (Continued)
180
150
VDD = VG = 12V
VDD = VG = 12V
175
145
140
135
130
125
120
115
170
165
160
155
150
145
140
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 27. TYPICAL MINIMUM DMOS TRANSISTOR “ON”
TIME vs TEMPERATURE
FIGURE 28. TYPICAL MINIMUM DMOS TRANSISTOR “OFF”
TIME vs TEMPERATURE
-0.50
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
-0.55
VDD = VG = 12V
-0.60
-0.65
-0.70
-0.75
-0.80
-0.85
-0.90
-0.95
-1.00
VDD = VG = 12V, DUTY CYCLE = 96%
4.5
4.0
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 29. TYPICAL MAXIMUM CONTROLLABLE PEAK
DMOS DRAIN CURRENT vs TEMPERATURE
FIGURE 30. TYPICAL COMPENSATING RAMP RATE
vs TEMPERATURE
1.80
11
1.75
VDD = VG = 12V
10
VDDMIN
1.70
1.65
1.60
1.55
1.50
1.45
1.40
1.35
1.30
1.25
1.20
9
8
7
6
VFB = 4V
5
4
3
2
VDDHYS
1
0
0
10
20
30
40
50
60
70
80
90 100
0
10
20
30
40
50
60
70
80
90 100
AMBIENT TEMPERATURE (oC)
AMBIENT TEMPERATURE (oC)
FIGURE 31. TYPICAL COMPENSATION RAMP DELAY
TIME vs TEMPERATURE
FIGURE 32. TYPICAL RISING V COMPARATOR THRESHOLD
DD
VOLTAGE vs TEMPERATURE
7-63
HIP5061
Typical Application Circuit
Figure 33 shows a Simplified Block Diagram of the HIP5061 in a
typical Boost converter. A resistor connected from the VIN supply
to the VDD terminal of the IC powers the internal 14V shunt
regulator. The Gate Driver supply is decoupled from the main
supply by a small external resistor connected between VDD and
the VG terminal. A bypass capacitor is connected between the
A 2MHz internal clock provides all the timing signals for the
converter operating at 250kHz. A slope compensation circuit
is also incorporated within the converter IC to eliminate sub-
harmonic oscillation that occurs in continuous-current mode
converters operating with duty cycles greater than 50%.
V
DD terminal and ground to reduce coupling between analog and
HIP5061 Description of Operation
digital circuitry. A Schottky diode insures efficient energy transfer
from the DMOS drain circuit inductor to the load. To set the
output voltage, two resistors are used to scale the output supply
voltage down to the 5.1V internal reference.
Figure 2 shows a more detailed Functional Block Diagram of
the HIP5061. An internal 14V shunt regulator in conjunction
with an external series resistor provides internal operating
voltage to the IC in applications where no 12V auxiliary sup-
ply is available. Note that In applications where the input
voltage at VDD is 12V, +/-10%, the regulator is not used. This
regulator is shown as a zener diode on the diagrams of Fig-
ure 2 and Figure 33.
The heart of the IC is the high current DMOS power
transistor with its associated gate driver and high-speed
peak current control loop. A portion of the converters DC
output is applied to a transconductance error amplifier that
compares the fed back signal with the internal 5.1V
reference. The output of this amplifier is brought out at
the VC terminal to provide for soft start and frequency
compensation of the control loop. This same signal is also
applied internally to program the peak DMOS transistor
drain current. To assure precise current control, the
response time of this peak current control loop is less
than 50ns.
The 2MHz clock is processed in the Control Logic block to
provide various timing signals. A cycle of operation begins
when a 100ns pulse (which occurs at a 4µs interval) triggers
the latch that initiates the DMOS transistor on-time. This
pulse also provides a blanking interval in the Current Moni-
toring block to eliminate false turn-offs caused by high tran-
sient pulse currents that occur during turn-on. The output of
VIN
VOUT
VDD
VDD CLAMP
VG
DRAIN
HIP5061
GATE
DRIVER
TAB
(SOURCE)
CONTROL
LOGIC
2MHz
CLOCK
VC
OVER
TEMP
AMP
FB
V/I
2.6V
UNDER
VOLTAGE
SLOPE
COMPENSATION
5.1V
REFERENCE
GND
FIGURE 33. SIMPLIFIED BLOCK DIAGRAM OF THE HIP5061 IN A TYPICAL "BOOST" CONFIGURATION
7-64
HIP5061
the Current Ramp block is summed with the sensed DMOS impedance, ideally infinity. The amplifier gain is typically
transistor current (to provide slope compensation) before 50dB and is not significantly altered when operating into the
being compared with the Error Current signal. The current stages that follow within the IC. To minimize the output stage
ramp, -0.45A/µs, is inhibited for the first 1.5µs (37.5%) of the idling current, while providing high peak currents to insure
duty cycle by the Ramp Enable signal, since ramp is not rapid response to load and input transients, a class B type of
needed for slope compensation during this interval. Inhibit- output stage was used in the amplifier. Placing a 100k
ing of the compensating ramp has the effect of reducing the resistor from the amplifier output terminal, VC, to ground will
peak short-circuit current.
bias the output stage to an active state and still minimize
power consumption. In all cases, the resistor shunting the
transconductance amplifier output must be greater than
10kΩ to insure that the output will rise sufficiently high to
obtain the maximum DMOS transistor drain current.
The output of the power supply is divided down and
monitored at the FB terminal. A transconductance error
amplifier compares the DC level of the fed back voltage with
an internal bandgap reference, while providing voltage loop
compensation by means of external resistors and Start-Up Sequence
capacitors. The Error Amplifier output (the error voltage) is
Upon initial power up of the HIP5061 in a typical application
then converted into a current (the Error Current) that is used
to program the required peak DMOS transistor current that
produces the desired output voltage. When the sum of the
sensed DMOS transistor current and the compensating
ramp exceed the Error Current signal, the latch is reset and
the DMOS transistor is turned off. Current comparison
around this loop takes place in less than 50ns, allowing for
excellent 250kHz converter operation. The latch can also be
reset by an under-voltage (VDD < 10.3V typical), over
temperature (TJ > +125oC typical) or a shutdown signal
externally applied at the VC terminal. See Figure 36.
circuit, the voltage at VC will be zero, and the DMOS transis-
tor will be off. When the voltage at VDD rises above the
10.3V typical threshold, the error amplifier output is enabled
and the VC voltage begins to rise in response to the low volt-
age at the FB terminal. When the VC voltage rises above
1.5V the DMOS transistor begins to switch at the minimum
duty cycle, and when it rises above 2.55V the duty cycle
begins to increase. The VC voltage (and peak DMOS tran-
sistor current) will then continue to rise until the voltage loop
gains control and establishes regulation. Note that the rate
of rise in the VC voltage can be controlled by an external soft
Note that if the error voltage (at the VC pin) is less that start circuit (See Soft Start Implementation).
2.55V, then the output of the Voltage-to-Current Converter
If the VC voltage is unrestricted in its rate of rise, then it will
will be held at zero. This condition will produce the minimum
typically rise quickly to its maximum (peak current) value,
possible pulse width, typically 150ns (100ns blanking pulse
causing the DMOS transistor to turn-on and stay on until it
plus 50ns delay). Error voltages lower than this 2.55V level
reaches the peak current value. At this point, the DMOS
will not produce shorter pulse widths. Under very light loads
transistor begins switching, and the VC voltage (and peak
(when VC goes below 1.5V), the Enable Comparator will
DMOS transistor current) will drop down to the level com-
manded by the voltage loop.
temporarily hold-off the PWM latch (and the DMOS transis-
tor) until the VC voltages rises above 1.5V. This low VC
inhibit circuit results in a burst-mode of operation that main-
tains regulation under light or no loads.
Using the Shunt Regulator
The internal 14V shunt regulator in conjunction with an
During an over-current condition, the output of the Error
external series resistor allows the IC to operate from quite
Amplifier will attempt to exceed the 7.0V threshold. At this
high input voltages, limited only by power dissipation in the
point, the Short-Circuit Comparator will pull down on this sig-
external resistor. When only higher voltages are available, a
nal and induce a low-level oscillation about the threshold,
bootstrap or other 12V auxiliary supply can be used to elimi-
serving to clamp the peak error voltage. This clamping
nate this dissipation. The series resistor should be chosen to
action, in turn, will limit the peak current in the DMOS tran-
be as large as possible to reduce power dissipation at high
sistor, reducing the duty ratio of the switch as the demand for
line, while ensuring adequate VDD voltage at low line. The
current continues to increase. This action, in conjunction
maximum value for this resistor, R, is given by:
with the Thermal Monitor, serves to protect the IC from over-
current (short-circuit) conditions.
V
– 10.5
I, MIN
R
(Ω) =
----------------------------------------
Using the Transconductance Error Amplifier
MAX
0.033
A transconductance amplifier with a typical gm of 30mS is
used as the input gain stage where the power supply output
voltage is compared with the internally generated 5.1V
reference voltage. A PNP transistor input structure allows
this amplifier to accommodate large negative going transient
voltages without causing amplifier phase reversal, often
associated with PNP input structures. Negative transients up
to 5V applied to the input though at least 5.1k will not result
in phase reversal. The amplifier output stage has the
customary drain to drain output to help improve the output
Where VI is the input voltage to the power supply. The value
chosen for this resistor must also result in a current, I, into
the VDD clamp that is less than 105mA when the input volt-
age is at its maximum:
V
– 13.3
I, MAX
R
I
(A) =
-------------------------------------------------
MAX
MAX
7-65
HIP5061
TABLE 2. MINIMUM INDUCTANCE FOR STABLE CCM
OPERATION ABOVE 50% DUTY CYCLE
Inductor Selection
The selection of the energy storage inductor(s) LSTOR for a DC to
DC converter has tremendous influence on the behavior of the
converter. It is particularly important in light of the high level of
integration (and necessarily few degrees of freedom) achieved in
the HIP5061. There are several factors influencing the selection
of this inductor. First, the inductance of LSTOR will determine the
basic mode of operation for the converter: continuous or
discontinuous current. In order to maximize the output power
for the given maximum controllable DMOS transistor current, a
converter may be designed to operate in continuous current
mode (CCM). However, this tends to require a larger inductor,
and for many converter topologies results in a feedback loop
tha is difficult to stabilize. For these and other reasons, the
inductor LSTOR may be chosen so as to operate the converter in
discontinuous current mode (DCM). The relative merits of
CCM and DCM operation for various topologies and the
corresponding selection of LSTOR is well documented and will not
be covered here.
CONVERTER TYPE MINIMUM INDUCTANCE
VO + VD – VI, MIN
-------------------------------------------
2MR, MIN
Boost
L =
L1L2
V
O + VD
----------------- ----------------------
L1 + L2 2MR, MIN
SEPIC (Note 1)
Cuk (Note 2)
Flyback
>
L1L2
VO – VD
----------------- > ----------------------
L1 + L2 2MR, MIN
NP (VO + VD)
LP
>
------ ---------------------------
NS 2MR, MIN
NS (VO + VD)
Forward
L >
------ ---------------------------
NP 2MR, MIN
A second factor influencing the selection of LSTOR is the
stability requirement for current-mode control. This constraint is
only applicable for converters operating in CCM, since open-
loop instabilities of this type are not observed in converters
operating in DCM. For marginal stability, the compensating
ramp (internal to the HIP5061) must have a slope that is
greater than one-half the difference between the inductor
current’s down slope and up slope. (To ensure stability for duty
ratios D > 0.8, the slope of the compensating ramp should be
equal to the inductor current downslope.) A generally accepted
goal is to set the slope of the compensating ramp to be at least
one-half of the inductor current down slope. Since there is no
external control over the internal compensating ramp, one must
be sure that the inductor is large enough so that the down slope
of the inductor current is not too large. Table 2 summarizes this
requirement for minimum inductance for several common
topologies.
NOTES:
1. Assumes that L and L are both CCM.
1
2
2. L = Inductance in Henrys, V = Output Voltage,
O
V
= Diode Voltage Drop, V = Input Voltage,
D
I
M
= (∆I/∆t)
= 0.45A/µs, L = Drain Inductor,
MIN 1
R,MIN
L = Secondary Inductor, N = Primary Turns,
2
P
N
= Secondary Turns
S
DMOS Transistor Turn-Off Snubber
In order to reduce dissipation in the DMOS transistor due to
turn-off losses, the turn-off time has been minimized.
However, the rapid reduction of current that occurs in the
drain of the DMOS transistor can result in large transient
voltages being induced across any parasitic inductance in
A third constraint on the size of the inductor is one that is the drain path. For this reason, it is important that such
common among current-mode controlled PWM converters, parasitic inductance be reduced by good, high frequency
and applies to both DCM and CCM operation. The stable layout practices. Nevertheless, there are many instances
generation of the desired DMOS transistor pulse width (e.g., transformer isolated topologies) in which voltages in
depends on the accurate comparison of the error signal and excess of 60V may be developed at the DMOS transistor
the peak LSTOR (DMOS) transistor drain current. Thus, as drain. In some cases, a simple R-C snubber may be added
the peak LSTOR ripple current becomes smaller, immunity to reduce the overshoot of the drain voltage to a safe level.
from noise on the error signal is eventually reduced until the
It is also possible that the large amount of ringing that can
pulse width can no longer be adequately controlled. For the
occur at the DMOS transistor drain at turn-off will induce
HIP5061, the inductor current ripple must be at least 200mA
noise in the IC. This noise may result in false triggering of
peak to peak to ensure proper control of the DMOS
the PWM latch, particularly at high peak DMOS transistor
transistor current. This effectively establishes a maximum
drain currents. Noise related instability can also be elimi-
value for the inductor LSTOR, so as to maintain at least
nated by the addition of a snubber, which will rapidly damp
200mA of ripple. Note that under extremely light or no load
out such turn-off ringing. Good layout practices will reduce
conditions, all converters will eventually operate in DCM,
the need for such protective measures, and ensure that the
and the 200mA requirement will eventually be violated.
DMOS transistor is not overstressed.
Under these conditions, the HIP5061 will continue to
regulate, although the switching of the DMOS transistor will
Under-Voltage Lockout
be in
a burst-mode, controlled by the Light Load
The VDD input voltage is monitored by a comparator that
holds off the DMOS transistor gate drive signal when the
Comparator. (See Figure 2.)
VDD voltage is less that about 10.3V. The typical 0.5V hyster-
7-66
HIP5061
esis of this comparator is intended to reduce oscillation DMOS Transistor Turn-On Noise
when the voltage at VDD is in the vicinity of 10V. Note, how-
Although the large DMOS transistor turn-on current spikes are
ever, that when an external series resistor is used to feed the
shunt regulator, the voltage drop across this resistor (which
sharply decreases when the IC shuts down), effectively
reduces the hysteresis. To reduce the tendency for oscilla-
tion in the vicinity of the 10V threshold, the impedance of the
source that feeds the DC to DC converter input should be
minimized. The addition of a capacitor (1µF-47µF) at the
“blanked over” by the control circuit, it is important to minimize
these current spikes, since they often result in voltage spikes
considerably below the device substrate that can activate par-
asitic devices within the IC. Such activation of parasitic
devices will often result in improper operation of the IC. An
external terminal labeled VG brings out the power supply to
the gate drive circuitry. This allows for the control of the peak
current delivered to the gate of the DMOS transistor, which in
turn establishes the turn-on speed. The VG pin may be exter-
nally bypassed for the fastest possible turn-on, or series resis-
tance may be added with no bypassing capacitor to slow
down the turn-on of the DMOS transistor. Depending upon the
actual layout of the supply, it is generally recommended that a
series resistor be added (10Ω-150Ω) so that the DMOS tran-
sistor turn-on speed is reduced. By properly adjusting the
turn-on speed, undershoot can be avoided while turn-on
switching losses are kept to a minimum.
VDD terminal can also help to provide smooth turn-on or turn-
off of the converter if the input supply rises or falls gradually
through the VDD Comparator threshold.
Peak Controllable DMOS Transistor Current
Figure 34 shows the guaranteed minimum, peak controllable
DMOS transistor current versus duty cycle. This peak cur-
rent value is established by the current limit circuitry, which
effectively clamps the voltage at VC (the error voltage) to
perform current limiting. Since the sensed DMOS transistor
current is summed with a compensating current ramp that
begins its rise 1.5µs after the initiation of a cycle, current lim-
iting will begin to occur at a peak DMOS transistor current
that varies with the operating duty cycle. The highest current
limit threshold occurs for D<0.375, where no ramp is added
to the sensed DMOS transistor current. At higher operating
duty ratios, the onset of current limit will occur at increasingly
lower currents, due to the effect of adding the compensating
ramp to the sensed current. Note that this curve represents
guaranteed minimum values. The guaranteed maximum val-
ues are considerable higher, although they are still limited to
levels that protect the IC.
Soft Start Implementation
It is often desirable to allow the regulator to start up slowly,
Figure 35 shows one means of implementing this action. The
normally high output current from the HIP5061 transconduc-
tance amplifier (when VFB = 0 and VREF = 5.1V) is directed to
an external capacitor through a diode. This slows down the
rate of rise of the voltage at the VC terminal. After the regula-
tor starts, the external capacitor is charged to VDD and is
effectively removed from the frequency compensation net-
work by a reverse biased diode. To ensure rapid recycling of
the capacitor voltage with removal of power, a diode is placed
across the 100kΩ resistor. Logic Shutdown Input (VC Pin).
7
5
3
1
100kΩ
VDD
VC
VG
DRAIN
2mA, TYP
GATE DRIVER
AND CONTROL
CIRCUITRY
20µF
FB
SOFT START
NETWORK
HIP5061
GND
SOURCE
100kΩ
0.1µF
1.0
0.375
0.06
DUTY CYCLE
TYPICAL FREQUENCY
COMPENSATION NETWORK
FIGURE 34. PEAK DMOS TRANSISTOR DRAIN CURRENT vs
DUTY CYCLE
FIGURE 35. SOFT START CIRCUIT FOR THE HIP5061
When the DMOS transistor first turns ON there may be sub-
stantial current spikes exceeding the normal maximum peak
current established by the current control stages within the
IC. To prevent these spurious spikes from conveying errone-
ous information to the Current Comparator, a 100ns blanking
signal is applied to the current monitoring circuitry. Thus,
there is no peak current protection during the first 6% of the
duty cycle (see Figure 36).
The DC to DC converter may be shut down by returning the
VC output terminal to ground. A sinking current greater than
4mA will insure that this output is pulled to ground. It must be
remembered that once switching operation ceases, the drain
of the DMOS transistor is open. When the supply is in the
Boost configuration, the output voltage is not zero but the input
voltage less diode and inductor voltage drops. If the SEPIC
7-67
HIP5061
topology is used, this is not the case. Shutting down the regu- All the capacitors shown with values of 1µF or less are of the
lator via the VC terminal will cut off the output. Figure 36 shows multilayer ceramic type with the X7R dielectric material. This
two methods of shutting down the IC. In each case the current material has a fairly flat voltage and temperature coefficient
sinking circuit must be able to sink at least 4mA, the maximum that assures that the capacitance remains comparatively con-
current from the HIP5061 VC terminal.
stant at extreme operating temperatures and voltages. The
multilayer construction allows for comparatively large values
with good volumetric efficiency and low inductance. Capaci-
tors around the power input and output circuits should be
returned to the device TAB via a low inductance ground plane.
This TAB is internally connected to the DMOS transistor
source. The schematic diagram of Figure 38 was drawn with
the diagonal leads to show the critical paths for the various
high frequency elements. These short interconnects assure
the lowest inductance around the output power circuit.
VDD
VG
DRAIN
FROM CD4049UB
4mA
VC
GATE DRIVER
AND CONTROL
CIRCUITRY
OFF
OFF
FB
Design of a 28V, 1.8A Boost Converter
GND
SOURCE
HIP5061
Figure 38 shows the schematic diagram and a parts list of a
50W supply designed with the HIP5061. Table 3 tabulates
the performance of the power supply.
NOTE: FREQUENCY
COMPENSATION NETWORK
NOT SHOWN
ALTERNATE METHOD
TABLE 3. TYPICAL LABORATORY PERFORMANCE OF
50W, 28V/1.8A REGULATOR
FIGURE 36. TWO METHODS OF SHUTTING DOWN THE HIP5061
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11V to 16V
Line Regulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12mV/V
Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28.0V
Load Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 64mV/A
Mounting, Layout and Component
Selection
The TO-220 package with its gullwing leads was designed to
be surface mounted. To aid in the external reduction of lead
length and hence inductance and resistance, the IC leads
were staggered. To keep the inductance and resistance of
the critical drain terminal as low as possible, it is suggested
that the PC trace to the DMOS transistor drain terminal be
made as wide as possible. The adjacent source terminal is
not recommended to be used and therefore allows the metal
to the drain terminal to be widened beyond the normal
widths for these terminals. Figure 37 illustrates these points.
Output Ripple, FL . . . . . . . . . . . . . . . . . . . . . . . . . . 600mV P-P
(20MHz BW)
Output Ripple, after Filter, FL . . . . . . . . . . . . . . . . . 80mV P-P
(20MHz BW)
Efficiency: V = 11V, I = 0.18A. . . . . . . . . . . . . . . 90%
I
L
V = 11V, I = 1.8A. . . . . . . . . . . . . . . . 89%
I
L
V = 16V, I = 0.18A. . . . . . . . . . . . . . . 73%
I
L
V = 16V, I = 1.8A. . . . . . . . . . . . . . . . 93%
I
L
One of the most important aspects to the proper application
of this device is high frequency bypassing. In a Boost con-
verter, for example, there should be a low-inductance inter-
connect from the DMOS transistor drain, through the output
diode and capacitors, and returning to the TAB (source) of
the HIP5061. Inductance in this line results in large transient
voltages on the DMOS transistor drain terminal which can
result in voltages above the maximum DMOS transistor
drain voltage rating.
Inductor Selection
In order to maximize the output power for the given maxi-
mum controllable DMOS transistor current, this converter
has been designed to operate in continuous current mode
(CCM). In this mode, the inductor value will generally be
large, resulting in a lower inductor ripple current and a lower
peak DMOS current. To ensure that the converter operates
in CCM over the usable range of input voltage and output
current, the value of L2 must be greater than the “critical
inductance,” given by
IC SOLDERED TO PC BOARD
VG PC METAL
VDD PC METAL
WIDER
DRAIN
2
V
V
V
+ V – V
T
PC METAL
FOR LOWER
INDUCTANCE
O I, MAX
O
D
I, MAX
S
L
=
----------------------------------------------------------------------------------------------------------
CRIT
2
2P
2
V
+ V
O, MIN
O
D
HIP5061
NORMAL
PC METAL
FOR FB
(28) (16) (28 + 0.5 – 16) 4×10–6
-------------------------------------------------------------------------------------------------
2
=
AND VC
2 (5.6) (28 + 0.5)
GROUND PC METAL
= 39µH
FIGURE 37. SHOWING WIDER PC BOARD METAL FOR
CRITICAL
7-68
HIP5061
where PO,MIN has been arbitrarily chosen as 5.6W, corre-
D.C. Gain: 20dB-40dB
sponding to an output current of 0.2A, and VD is the forward
voltage of CR1. Thus, for L2 > 39µH, the converter will be in
CCM for VI = 11V to 16V and IL = 0.2A to 1.8A.
Pole at 88Hz-880Hz
LHP Zero at 1MHz
RHP Zero at 11.0kHz-110kHz
Double Pole at 80kHz (from filter)
A second factor influencing the selection of L2 is the stability
requirement for current-mode control. Using the above
equation for LMIN for the Boost converter:
To stabilize the voltage loop, it is necessary to establish the
unity gain crossover frequency well below the RHP zero, since
this zero introduces positive gain and negative phase. A cross-
over of 4kHz is fairly conservative, and is achieved by adding a
1µF capacitor at the VC pin, which provides near infinite DC
gain, and about -5dB of gain at 4kHz. This results in a phase
margin of about 15o at full load. Note that R4 is required for
proper operation of the transconductance amplifier, since it is
providing bias current for the output stage as discussed under
Using the Transconductance Error Amplifier section.
V
+ V – V
O
D
I, MIN
28 + 0.5 – 11
L >
=
= 19µH
-----------------------------------------------------
--------------------------------------------------------
2 × M
6
RAMP, MIN
2 × 0.45×10 A ⁄ S
Thus, L2 must be at least 19µH to ensure good stability of
the current loop, and a choice of L2 = 40µH satisfies this
requirement, while maintaining CCM operation over an
extremely wide load range.
Output Filter Design
Inductor L3 was chosen with C11 to provide at least 15dB of
ripple attenuation at the switching frequency. The corner fre-
quency (80kHz) of this filter is well above the crossover fre-
quency of the voltage loop (4kHz), and has no effect on
stability. This secondary LC filter was used to reduce output
ripple instead of a lower-cost, high-value, low ESR alumi-
num electrolytic capacitor to demonstrate the reduction in
volume possible at this switching frequency. A lower cost
solution could achieve the same output ripple by replacing
C9,10,12 and L3 with one or two large capacitors (e.g.,
The chosen core material for L2 is Kool Mu ferrous alloy pow-
der from Magnetics, Inc. This material was chosen because of
its relatively low cost, while its losses due to AC flux are five to
ten times less than conventional powdered iron.
Loop Compensation
The control to output transfer function for this current-mode
boost converter has the following characteristics over the
specified load and line conditions:
L3, 4µH
1µF,
50V
L2, 40µH
CR1
C4
RA
20Ω, 1W
INPUT
11VDC - 16VDC
C12
47µF,
C3
1µF,
50V
C11
1µF,
50V
R11
50V
C5
R5
10Ω, 1/4W
OUTPUT
28VDC
0A - 1.8A
7.5Ω, 1/2W
C9
6.8µF,
50V
7
6
5
R1
10K,
1%
47µF,
50V
C13
1nF,
100V
VDD
VG
OPTIONAL
FILTER
DRAIN
GATE DRIVERS,
CONTROL CIRCUITRY
AND LOGIC
C10
6.8µF,
50V
TAB
3
1
(SOURCE)
FB
GND
1µF,
50V
R2
2.21K, 1%
C1
2
R4
100K
HIP5061
VC
PARTS LIST
C1, C3, C4 and C11 1µF, 50V, Ceramic - Murata Erie RPE113X7R105050V
C5 and C12 47µF, 50V, Alum - United Chemicon 515D476M050
C9 and C10 6.8µF, 50V, Ceramin - Mallory M60u6r8M50
C13 1nF, 100V, Ceramin - Kemet C322C102K1G5CA
CR1 Schottky Diode - Motorola MBRD360
RA 20Ω, 1W, Wirebound - Dale RWR81S20R0FR or Equivalent
R1 10K, 1%
R2 2.2K, 1%
R4 100K, 1/4W
R5 10Ω, 1/4W
L2 40µH at 5A, Pulse Engineering PE - 53571
R11 7.5Ω, 1/2W, Carbon - Allen Bradley EB75G5
L3 4µH at 5.5A, Pulse Engineering PE - 53570
FIGURE 38. HIP5061 50W, 28V BOOST REGULATOR SCHEMATIC AND PARTS LIST
7-69
HIP5061
390µF, 50V, type 673D from United Chemicon). This change Snubber Network
would also greatly improve load transient response, pro-
A snubber network has been added to reduce the ringing at
vided that the loop compensation is appropriately adjusted.
Note that in the circuit of Figure 38, capacitor C12 does not
significantly affect output ripple, but is necessary to absorb
the energy stored in L2 during severe load transients. In the
event of a step change in load from 1.8A to 0A, C12 will limit
the output voltage overshoot to about 10V and protect the
drain of the DMOS transistor from overvoltage breakdown.
the drain due to parasitic layout inductances. In particular,
under severe load transient conditions, this snubber is nec-
essary to protect the drain from voltage breakdown. A sec-
ond benefit of reducing the noise and ringing at the drain is
that it reduces the tendency of the HIP5061 to exhibit noise-
related instabilities at high peak DMOS transistor currents
(4A-6A). A value of 1000pF was chosen for C13, since this
is adequate to dampen the ringing associated with the
200pF drain capacitance of the DMOS transistor. R11 was
chosen as 7.5Ω to provide the best possible dampening
given the parasitic inductances that exist in the layout. Note
that this snubber may not be necessary if the layout of the
circuit were improved, or if the application did not push the
envelope of DMOS transistor current.
Input and VDD Filters
Since the boost converter is current fed, input filtering is eas-
ily achieved by the addition of a small capacitor C4. This
capacitor provides nearly 40dB of ripple current attenuation
for the input, reducing the AC ripple current flowing into the
converter to less than 200mA.
R5 and C3 have been chosen to provide good filtering of
high frequency pulse currents. R5 provides isolation
Other Power Supply Topologies
between the analog VDD pin and the high pulse current VG Figure 39 shows three other topologies besides the Boost that
pin, and also provides a means to control the turn-on speed may be implemented with the grounded source DMOS power
of the DMOS transistor by limiting the peak current available transistor used in the HIP5061. Other, more complex power
to the internal gate drive circuitry. Thus the output transition supply topologies such as the Quadratic are also possible to
time may be increased to prevent drain voltage undershoot. implement with the HIP5061. One noteworthy feature of the
Undershoot may result in activation of device parasitics and Quadratic topology as shown in Figure 41 is the wide input to
improper circuit operation. For the two-layer board used for output voltage transfer ratio possible with reasonable duty
this design, C3 could be reduced to 0.22µF without affecting cycles. Duty cycles that are not near the Minimum DMOS tran-
circuit operation. C5 was added to provide low-frequency fil- sistor “ON” Time specification shown in the Data Sheet. This
tering at the VDD pin. This reduces the tendency of the circuit permits easier control at the extremes of the transfer ratios.
to oscillate off and on when the voltage at the VDD pin s in Compensating the control loop can pose challenges because
the vicinity of the under voltage lockout threshold, typically of the wider changes in the transfer ratio and hence loop gain.
10V, and the output power is high (30W - 50W).
The SEPIC topology[11,13] does not have quite as wide input-
Shunt Regulator Resistor
output voltage range with reasonably controlled duty cycles
as the Quadratic converter mentioned above, but it does
allow both voltage increase and decrease with the same cir-
cuit. This is particularly advantageous when a power supply
is being used in the stabilizing mode and isolation is not
required. For example, in an application where a regulated
24V output is required and the input voltage varies ±20%
from a nominal 24V. The SEPIC supply can provide both the
Boost and Buck functions.
Resistor RA has been chosen to be as large as possible to
reduce power dissipation at high line, while ensuring ade-
quate VDD voltage at low line. Note that the guaranteed
range of input voltage for proper operation of this circuit is
11.2V to 15.3VDC, based upon data sheet limits. However,
the circuit was found to perform well at room temperature for
VI = 10.7VDC to 17VDC. The maximum value for RA is
V
– 10.5
Another outstanding advantage of the SEPIC topology is its
fault isolation of the input and output voltage. All energy is
transferred via the coupling capacitor. Moreover if the clock
stops, voltage transfer stops. If the switching transistor shorts
there is no output. The Buck circuit will apply full input voltage
to the load with a shorted transistor. This is reason that the
SEPIC topology is referred to as the fail-safe Buck.
I, MIN
R
=
= 21Ω
----------------------------------------
MAX
0.033
RA has been chosen as 20Ω, which results in a current into
the VDD clamp that is less than 105mA when the input volt-
age is at its maximum:
V
– 13.3
I, MAX
I
=
= 100mA < 105mA
-------------------------------------------------
MAX
20.0
7-70
HIP5061
+
+
+
+
VOUT
-
VDD
VG
DRAIN
GATE DRIVER
AND CONTROL
CIRCUITRY
VIN
VOUT
VC
FB
VDD
VG
DRAIN
HIP5061
VIN
GATE DRIVER
AND CONTROL
CIRCUITRY
GND
SOURCE
-
-
VC
COUPLING
MEANS
FB
ISOLATED
OR DIRECT
HIP5061
GND
SOURCE
-
FIGURE 39A. SEPIC (FAIL-SAFE BUCK) CONVERTER
+
-
FIGURE 40. FLYBACK CONVERTER
VDD
VG
DRAIN
It should be noted that when the Cuk topology is imple-
mented, a transistor current source is used to convert the
negative output voltage of the Cuk converter to a current that
is level shifted to the FB terminal on the HIP5061.
GATE DRIVER
VIN
AND CONTROL
CIRCUITRY
VC
FB
VOUT
HIP5061
GND
Two other useful topologies that may be used are the For-
ward and the Flyback as shown in Figure 40 and Figure 41.
As shown, they may either be operated as an isolated or
non-isolated converter.
SOURCE
FIGURE 39B. CUK CONVERTER
+
+
+
VOUT
+
-
VDD
VG
DRAIN
VDD
VG
DRAIN
GATE DRIVER
AND CONTROL
CIRCUITRY
VOUT
VIN
VIN
GATE DRIVER
AND CONTROL
CIRCUITRY
VC
FB
VC
COUPLING
MEANS
FB
HIP5061
ISOLATED
OR DIRECT
GND
SOURCE
HIP5061
-
-
GND
SOURCE
-
FIGURE 39C. QUADRATIC CONVERTER
FIGURE 39. THREE OTHER TOPOLOGIES
FIGURE 41. FORWARD CONVERTER
7-71
HIP5061
Both the SEPIC and the Boost topologies may be operated
References
at high voltages with the addition of a high voltage cascode .
Figure 42 shows the Cascode SEPIC converter that is
essentially limited by the selection of the external power
transistor. The burden of voltage, and power is placed upon
the external transistor. The HIP5061 still performs the drain
current sampling and the control function is the same as the
non cascode configuration.
[1] Cassani, John C.; Hurd, Jonathan J. and Thomas, David
R., Wittlinger, H.A.; Hodgins, Robert G.; Sophisticated
Control IC Enhances 1MHz Current Controlled Regulator
Performance, High Frequency Power Conversion (HFPC)
conference proceedings, May 1992, pp. 167-173
[2] Smith, Craig D. and Cassani, Distributed Power Systems Via
ASICs Using SMT, Surface Mount Technology, October 1990
[3] Maksimovic and Cuk, Switching Converters With Wide DC
Conversion Range, High Frequency Power Conversion
(HFPC) conference record, May 1989
+
+
[5] Maksimovic and Cuk, General Properties and Synthesis of
PWM DC-to-DC Converters, IEEE Power Electronics
Specialists Conference (PESC) record, June 1989
VOUT
160V
VIN
VDD
VG
DRAIN
[6] Sokal and Sokal, Class E - A New Class of High Efficiency
Tuned Single-Ended Switching Power Amplifiers, IEEE
Journal of Solid-State Circuits, June 1975, pp. 168-176
GATE DRIVER
AND CONTROL
CIRCUITRY
VC
FB
[7] Mansmann, Jeff; Shafer, Peter and Wildi, Eric, Maximizing
the Impact of Power ICs Via a Time-to-Market CAD Driven
Power ASIC Strategy, Applied Power and Electronics
Conference and Exposition (APEC) proceedings, Febru-
ary 1992, pp. 23-27
HIP5061
GND
SOURCE
-
-
[8] Severns and Bloom, Modern DC-to-DC Switchmode
Power Converter Circuits, Van Nostrand Reinhold, 1985
FIGURE 42. OFF LINE CASCODE SEPIC
[9] Sum, K., Switch Mode Power Conversion - Basic Theory
and Design, Marcel Dekker, In., 1984
Figure 43 shows the voltage transfer as a function of duty
cycle for the power supply topologies discussed.
[10] Pressman, A., Switching and Linear Power Supply,
Power Converter Design, Hayden Book Co., 1977
100
[11] Massey, R.P. and Snyder, E.C., High Voltage Single-
Ended DC-DC Converter, IEEE Power Electronics Spe-
cialists Conference (PESC) record, 1977, pp. 156-159
BUCK-BOOST, CUK AND SEPIC
M = D/(1-D)
10
[12] Clarke, P., A New Switched-Mode Power Conversion
Topology Provides Inherently Stable Response, POWER-
CON 10 proceedings, March 1983, pp. E2-1 through E2-7
M = 1/(1 - D) BOOST
1
[13] Intersil Application Notes AN9208 and AN9212.1
0.1
BUCK
M = D
QUADRATIC
M = D2/(1 - D)2
0.01
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
DUTY CYCLE (D)
FIGURE 43. VOLTAGE TRANSFER AS A FUNCTION OF DUTY
CYCLE FOR VARIOUS TOPOLOGIES
All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate
and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which
may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see web site http://www.intersil.com
7-72
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