RT8250 [RICHTEK]
3A, 23V, 340kHz Synchronous Step-Down Converter; 3A , 23V , 340kHz同步降压型转换器型号: | RT8250 |
厂家: | RICHTEK TECHNOLOGY CORPORATION |
描述: | 3A, 23V, 340kHz Synchronous Step-Down Converter |
文件: | 总12页 (文件大小:207K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
RT8250
3A, 23V, 340kHz Synchronous Step-Down Converter
General Description
Features
ꢀ 4.5V to 23V Input Voltage Range
The RT8250 is a high-efficiency synchronous step-down
DC/DC converter that can deliver up to 3Aoutput current
from 4.5V to 23V input supply. The RT8250's current mode
architecture and external compensation allow the transient
response to be optimized over a wide range of loads and
output capacitors. Cycle-by-cycle current limit provides
protection against shorted outputs and soft-start eliminates
input current surge during start-up. The RT8250 also
provides output under voltage protection and thermal
shutdown protection. The low current (<3μA) shutdown
mode provides output disconnection, enabling easy power
management in battery-powered systems.
ꢀ 1.5% High Accuracy Feedback Voltage
ꢀ 3A Output Current
ꢀ Integrated N-MOSFET Switches
ꢀ Current Mode Control
ꢀ Fixed Frequency Operation : 340kHz
ꢀ Output Adjustable from 0.925V to 20V
ꢀ Up to 95% Efficiency
ꢀ Programmable Soft-Start
ꢀ Stable with Low-ESR Ceramic Output Capacitors
ꢀ Cycle-by-Cycle Over Current Protection
ꢀ Input Under Voltage Lockout
ꢀ Output Under Voltage Protection
ꢀ Thermal Shutdown Protection
ꢀ Thermally Enhanced SOP-8 (Exposed Pad) Package
ꢀ RoHS Compliant and Halogen Free
Ordering Information
RT8250
Package Type
SP : SOP-8 (Exposed Pad-Option 1)
Applications
ꢀ Industrial and Commercial Low Power Systems
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
ꢀ Computer Peripherals
Richtek products are :
ꢀ LCDMonitors and TVs
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
ꢀ Green Electronics/Appliances
ꢀ Point of Load Regulation of High-Performance DSPs,
FPGAs and ASICs.
Pin Configurations
Marking Information
(TOP VIEW)
RT8250GSP : Product Number
RT8250
BOOT
VIN
8
7
6
5
SS
YMDNN : Date Code
GSPYMDNN
2
3
4
EN
GND
SW
COMP
FB
9
GND
SOP-8 (Exposed Pad)
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1
RT8250
Typical Application Circuit
1
3
2
V
IN
BOOT
RT8250
VIN
C
4.75V to 23V
C
IN
BOOT
L1
R
100k
EN
10µFx2
10µH
10nF
V
OUT
SW
3.3V/3A
7
8
EN
SS
R1
26.1k
C
OUT
5
6
FB
22µFx2
C
SS
0.1µF
4,
C
C
R
C
R2
3.9nF
Exposed Pad(9)
6.8k
10k
GND
COMP
C
P
NC
Table 1. Recommended Component Selection
V
OUT
(V)
R1 (kΩ)
R2 (kΩ)
R (kΩ)
C
C (nF)
C
L (μH)
C
(μF)
OUT
15
153
97.6
76.8
45.3
26.1
16.9
9.53
3
10
10
10
10
10
10
10
10
30
20
15
13
6.8
6.2
4.3
3
3.9
3.9
3.9
3.9
3.9
3.9
3.9
3.9
33
22
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
10
8
22
5
15
3.3
2.5
1.8
1.2
10
6.8
4.7
3.6
Functional Pin Description
Pin No.
Pin Name
Pin Function
Bootstrap for High Side Gate Driver. Connect a 10nF or greater ceramic capacitor
from the BOOT pin to SW pin.
1
BOOT
Voltage Supply Input. The input voltage range is from 4.5V to 23V. A suitable large
capacitor must be bypassed with this pin.
2
VIN
3
SW
Switching Node. Connect the output LC filter between the SW pin and output load.
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
4,
GND
9 (Exposed Pad)
Output Voltage Feedback Input. The feedback reference voltage is 0.925V
typically.
5
6
FB
Compensation Node. This pin is used for compensating the regulation control
loop. A series RC network is required to be connected from COMP to GND. If it is
needed, an additional capacitor should be connected from COMP to GND.
Enable Input. A logic high enables the converter, a logic low forces the converter
into shutdown mode reducing the supply current to less than 3μA. For automatic
startup, connect this pin to VIN with a 100kΩ pull up resistor.
COMP
7
8
EN
SS
Soft-Start Control Input. The soft-start period can be set by connecting a capacitor
from the SS to GND. A 0.1μF capacitor sets the soft-start period to 13ms typically.
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DS8250-05 March 2011
RT8250
Function Block Diagram
VIN
Current Sense
Amplifier
Internal
Regulator
Oscillator
340kHz/110kHz
Slope Comp
VA
+
-
Shutdown
Comparator
V
VA
CC
Foldback
Control
+
-
1.2V
BOOT
100mΩ
85mΩ
S
R
Q
Q
5k
-
EN
SS
SW
0.5V
+
+
+
-
2.5V
-
3V
Lockout
Comparator
UV
Comparator
GND
Current
V
CC
Comparator
7µA
0.925V
+
+
-
EA
COMP
FB
Absolute Maximum Ratings (Note 1)
ꢀ Supply Voltage, VIN ------------------------------------------------------------------------------------------ −0.3V to 24V
ꢀ Switching Voltage, SW ------------------------------------------------------------------------------------- −0.3V to (VIN + 0.3V)
<20ns ---------------------------------------------------------------------------------------------------------- −0.3V to (VIN + 3V)
ꢀ BOOT Voltage ------------------------------------------------------------------------------------------------- (VSW − 0.3V) to (VSW + 6V)
ꢀ The Other Pins ------------------------------------------------------------------------------------------------ −0.3V to 6V
ꢀ PowerDissipation, PD @ TA = 25°C
SOP-8 (Exposed Pad) -------------------------------------------------------------------------------------- 1.333W
ꢀ Package Thermal Resistance (Note 2)
SOP-8 (Exposed Pad), θJA --------------------------------------------------------------------------------- 75°C/W
SOP-8 (Exposed Pad), θJC -------------------------------------------------------------------------------- 15°C/W
ꢀ Junction Temperature ---------------------------------------------------------------------------------------- 150°C
ꢀ Lead Temperature (Soldering, 10 sec.)------------------------------------------------------------------ 260°C
ꢀ Storage Temperature Range ------------------------------------------------------------------------------- −65°C to 150°C
ꢀ ESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ----------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 4)
ꢀ Supply Voltage, VIN ------------------------------------------------------------------------------------------ 4.5V to 23V
ꢀ Enable Voltage, VEN ----------------------------------------------------------------------------------------- 0V to 5.5V
ꢀ Junction Temperature Range------------------------------------------------------------------------------- −40°C to 125°C
ꢀ Ambient Temperature Range------------------------------------------------------------------------------- −40°C to 85°C
DS8250-05 March 2011
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RT8250
Electrical Characteristics
(VIN = 12V, TA = 25°C unless otherwise specified)
Parameter
Symbol
Test Conditions
VEN = 0V
Min
--
Typ
0.3
Max
3
Unit
μA
Shutdown Supply Current
Supply Current
VEN = 3 V, VFB = 1V
4.75V ≤ VIN ≤ 23V
ΔIC = ±10μA
--
0.7
1.2
mA
V
Feedback Voltage
VFB
0.911 0.925 0.939
Error Amplifier Transconductance
High-Side Switch On-Resistance
Low-Side Switch On-Resistance
High-Side Switch Leakage Current
GEA
--
--
--
--
1250
100
85
--
--
μA/V
mΩ
mΩ
μA
RDS(ON)1
RDS(ON)2
--
VEN = 0V, VSW = 0V
0
10
Min. Duty Cycle
VBOOT – VSW = 4.8V
Upper Switch Current Limit
--
--
--
5.5
1.4
5.2
--
--
--
A
A
Lower Switch Current Limit
From Drain to Source
COMP to Current Sense
Transconductance
GCS
A/V
Oscillation Frequency
fOSC1
300
--
340
110
90
380
--
kHz
kHz
%
Short Circuit Oscillation Frequency fOSC2
VFB = 0V
Maximum Duty Cycle
Minimum On Time
DMAX
tON
VFB = 0.8V
--
--
--
200
--
--
ns
Logic-High
Logic-Low
VIH
2.7
--
--
EN Threshold
Voltage
V
VIL
--
0.4
Input Under Voltage Lockout
Threshold
Input Under Voltage Lockout
Threshold Hysterisis
VIN Rising
3.8
--
4.2
4.4
--
V
200
mV
Soft-Start Current
Soft-Start Period
Thermal Shutdown
VSS = 0V
--
--
--
7
--
--
--
μA
ms
°C
CSS = 0.1μF
13
TSD
150
Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity four-layer test board of
JEDEC 51-7 thermal measurement standard. The case position of θJC is on the exposed pad of the package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
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RT8250
Typical Operating Characteristics
Efficiency vs. Output Current
Output Voltage vs. Output Current
3.33
3.32
3.31
3.30
3.29
3.28
3.27
3.26
3.25
3.24
3.23
100
90
VIN = 23V
80
VIN = 12V
70
VIN = 4.75V
VIN = 4.75V
60
50
40
30
20
VIN = 12V
VIN = 23V
10
VOUT = 3.3V
VOUT = 3.3V
0
0
0.5
1
1.5
2
2.5
3
0
0.5
1
1.5
2
2.5
3
Output Current (A)
Output Current (A)
Reference Voltage vs. Input Voltage
Reference Voltage vs. Temperature
0.932
0.930
0.928
0.926
0.924
0.922
0.920
0.940
0.935
0.930
0.925
0.920
0.915
0.910
VIN = 6V, VOUT = 3.3V
VOUT = 3.3V, IOUT = 0A
4
6
8
10 12 14 16 18 20 22 24
Input Voltage (V)
-50
-25
0
25
50
75
100
125
(°C)
Temperature
Frequency. vs. Input Voltage
Frequency vs. Temperature
350
345
340
335
330
325
320
315
310
305
300
350
345
340
335
330
325
320
315
310
305
300
VIN = 12V, VOUT = 3.3V, IOUT = 0A
25 50 75 100 125
VOUT = 3.3V, IOUT = 0A
10 12 14 16 18 20 22 24
4
6
8
-50
-25
0
Input Voltage (V)
Temperature (°C)
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RT8250
Current Limit vs. Duty Cycle
Current Limit vs. Temperature
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
VOUT = 3.3V
VIN = 12V, VOUT = 3.3V
0
10 20 30 40 50 60 70 80 90 100
Duty Cycle (%)
-50
-25
0
25
50
75
100
125
Temperature (°C)
Power On from EN
Power Off from EN
VEN
(5V/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
VOUT
(2V/Div)
IOUT
(2A/Div)
IOUT
(2A/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 3A
Time (5ms/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 3A
Time (1ms/Div)
Power On from VIN
Switching
VOUT
(10mV/Div)
VIN
(5V/Div)
VSW
(10V/Div)
VOUT
(2V/Div)
IL
IL
(2A/Div)
(2A/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 3A
Time (5ms/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 3A
Time (1μs/Div)
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DS8250-05 March 2011
RT8250
Load Transient Response
Load Transient Response
VOUT
(200mV/Div)
VOUT
(200mV/Div)
IOUT
IOUT
(2A/Div)
(2A/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 0A to 3A
VIN = 12V, VOUT = 3.3V, IOUT = 0A to 1.5A
Time (100μs/Div)
Time (100μs/Div)
DS8250-05 March 2011
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RT8250
Application Information
can be programed by the external capacitor between SS
pin andGND. The chip provides a 7μAcharge current for
the external capacitor. If a 0.1μF capacitor is used to set
the soft-start and its period will be 13ms(typ.).
The RT8250 is a synchronous high voltage buck converter
that can support the input voltage range from 4.5V to 23V
and the output current can be up to 3A.
Output Voltage Setting
Inductor Selection
The resistive divider allows the FB pin to sense the output
voltage as shown in Figure 1.
The inductor value and operating frequency determine the
ripple current according to a specific input and output
voltage. The ripple current ΔIL increases with higher VIN
and decreases with higher inductance.
V
OUT
R1
FB
RT8250
GND
R2
V
f ×L
VOUT
V
IN
⎡
OUT ⎤ ⎡
× 1−
⎥ ⎢
⎤
ΔIL =
⎢
⎣
⎥
⎦
⎦ ⎣
Having a lower ripple current reduces not only the ESR
losses in the output capacitors but also the output voltage
ripple. High frequency with small ripple current can achieve
highest efficiency operation. However, it requires a large
inductor to achieve this goal.
Figure 1. Output Voltage Setting
The output voltage is set by an external resistive divider
according to the following equation :
R1
R2
⎛
⎝
⎞
⎟
⎠
VOUT = VFB 1+
⎜
For the ripple current selection, the value of ΔIL =
0.2375(IMAX) will be a reasonable starting point. The largest
ripple current occurs at the highest VIN. To guarantee that
the ripple current stays below the specified maximum,
the inductor value should be chosen according to the
following equation :
Where VFB is the feedback reference voltage (0.925V typ.).
External Bootstrap Diode
Connect a 10nF low ESR ceramic capacitor between the
BOOT pin and SW pin. This capacitor provides the gate
driver voltage for the high side MOSFET.
⎡
⎤ ⎡
× 1−
⎤
V
f × ΔI
V
OUT
V
IN(MAX)
OUT
L =
⎢
⎥ ⎢
⎥
It is recommended to add an external bootstrap diode
between an external 5V and the BOOT pin for efficiency
improvement when input voltage is lower than 5.5V or duty
ratio is higher than 65%. The bootstrap diode can be a
low cost one such as 1N4148 or BAT54.
L(MAX)
⎣
⎦ ⎣
⎦
Inductor Core Selection
The inductor type must be selected once the value for L
is known. Generally speaking, high efficiency converters
can not afford the core loss found in low cost powdered
iron cores. So, the more expensive ferrite or
mollypermalloy cores will be a better choice.
The external 5V can be a 5V fixed input from system or a
5V output of the RT8250. Note that the external boot
voltage must be lower than 5.5V.
5V
The selected inductance rather than the core size for a
fixed inductor value is the key for actual core loss. As the
inductance increases, core losses decrease. Unfortunately,
increase of the inductance requires more turns of wire
and therefore the copper losses will increase.
BOOT
RT8250
SW
10nF
Figure 2. External Bootstrap Diode
Ferrite designs are preferred at high switching frequency
due to the characteristics of very low core losses. So,
design goals can focus on the reduction of copper loss
and the saturation prevention.
Soft-Start
The RT8250 contains an external soft-start clamp that
gradually raises the output voltage. The soft-start timming
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DS8250-05 March 2011
RT8250
Ferrite core material saturates “hard”, which means that
inductance collapses abruptly when the peak design
current is exceeded. The previous situation results in an
abrupt increase in inductor ripple current and consequent
output voltage ripple.
The output ripple will be highest at the maximum input
voltage since ΔIL increases with input voltage. Multiple
capacitors placed in parallel may be needed to meet the
ESR and RMS current handling requirement.Dry tantalum,
special polymer, aluminum electrolytic and ceramic
capacitors are all available in surface mount packages.
Special polymer capacitors offer very low ESR value.
However, it provides lower capacitance density than other
types. Although Tantalum capacitors have the highest
capacitance density, it is important to only use types that
pass the surge test for use in switching power supplies.
Aluminum electrolytic capacitors have significantly higher
ESR. However, it can be used in cost-sensitive applications
for ripple current rating and long term reliability
considerations. Ceramic capacitors have excellent low
ESR characteristics but can have a high voltage coefficient
and audible piezoelectric effects. The high Q of ceramic
capacitors with trace inductance can also lead to significant
ringing.
Do not allow the core to saturate!
Different core materials and shapes will change the size/
current and price/current relationship of an inductor.
Toroid or shielded pot cores in ferrite or permalloy materials
are small and do not radiate energy. However, they are
usually more expensive than the similar powdered iron
inductors. The rule for inductor choice mainly depends
on the price vs. size requirement and any radiated field/
EMI requirements.
CIN and COUT Selection
The input capacitance, CIN, is needed to filter the
trapezoidal current at the source of the high side MOSFET.
To prevent large ripple current, a low ESR input capacitor
sized for the maximum RMS current should be used. The
RMS current is given by :
Higher values, lower cost ceramic capacitors are now
becoming available in smaller case sizes. Their high ripple
current, high voltage rating and low ESR make them ideal
for switching regulator applications. However, care must
be taken when these capacitors are used at input and
output. When a ceramic capacitor is used at the input
and the power is supplied by a wall adapter through long
wires, a load step at the output can induce ringing at the
input, VIN. At best, this ringing can couple to the output
and be mistaken as loop instability. At worst, a sudden
inrush of current through the long wires can potentially
cause a voltage spike at VIN large enough to damage the
part.
V
V
V
IN
V
OUT
OUT
I
= I
−1
RMS
OUT(MAX)
IN
This formula has a maximum at VIN = 2VOUT, where
IRMS = IOUT/2. This simple worst-case condition is
commonly used for design because even significant
deviations do not offer much relief.
Choose a capacitor rated at a higher temperature than
required. Several capacitors may also be paralleled to
meet size or height requirements in the design.
For the input capacitor, a 10μF x 2 low ESR ceramic
capacitor is recommended. For the recommended
capacitor, please refer to table 3 for more detail.
Checking Transient Response
The regulator loop response can be checked by looking
at the load transient response. Switching regulators take
several cycles to respond to a step in load current. When
a load step occurs, VOUT immediately shifts by an amount
equal to ΔILOAD (ESR) also begins to charge or discharge
COUT generating a feedback error signal for the regulator
to return VOUT to its steady-state value.During this recovery
time, VOUT can be monitored for overshoot or ringing that
would indicate a stability problem.
The selection of COUT is determined by the required ESR
to minimize voltage ripple.
Moreover, the amount of bulk capacitance is also a key
for COUT selection to ensure that the control loop is stable.
Loop stability can be checked by viewing the load transient
response as described in a later section.
The output ripple, ΔVOUT , is determined by :
1
⎡
⎤
ΔVOUT ≤ ΔIL ESR +
⎢
⎣
⎥
⎦
8fCOUT
DS8250-05 March 2011
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RT8250
Thermal Considerations
Layout Consideration
For continuous operation, do not exceed the maximum
operation junction temperature 125°C. The maximum
power dissipation depends on the thermal resistance of
IC package, PCB layout, the rate of surroundings airflow
and temperature difference between junction to ambient.
The maximum power dissipation can be calculated by
following formula :
Follow the PCB layout guidelines for optimal performance
of the RT8250.
` Keep the traces of the main current paths as short and
wide as possible.
` Put the input capacitor as close as possible to the device
pins (VINandGND).
` SW node is with high frequency voltage swing and
should be kept at small area. Keep sensitive
components away from the SW node to prevent stray
capacitive noise pick-up.
PD(MAX) = ( TJ(MAX) − TA ) / θJA
Where TJ(MAX) is the maximum operation junction
temperature, TA is the ambient temperature and the θJA is
the junction to ambient thermal resistance.
` Place the feedback components to the FB pin and
For recommended operating conditions specification of
RT8250, the maximum junction temperature is 125°C. The
junction to ambient thermal resistance θJA is layout
dependent. For PSOP-8 package, the thermal resistance
COMP pin as close as possible.
` TheGNDpin and Exposed Pad should be connected to
a strong ground plane for heat sinking and noise
protection.
θ
JA is 75°C/W on the standard JEDEC 51-7 four-layers
Input capacitor must be placed
as close to the IC as possible.
thermal test board. The maximum power dissipation at TA
= 25°C can be calculated by following formula :
SW
GND
V
IN
C
S
The feedback
PD(MAX) = (125°C − 25°C) / (75°C/W) = 1.333W for
PSOP-8 package
components must be
connected as close to
the device as possible.
C
IN
BOOT
VIN
8
SS
C
C
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA. For RT8250 package, the Figure 3 of
derating curve allows the designer to see the effect of
rising ambient temperature on the maximum power
dissipation allowed.
2
3
4
7
6
5
EN
GND
L1
V
SW
COMP
FB
OUT
R
C
C
P
C
GND
OUT
R1
V
OUT
R2
SW should be connected to inductor by
wide and short trace. Keep sensitive
components away from this trace.
GND
1.6
Four-Layer PCB
Figure 4. PCB Layout Guide
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0
25
50
75
100
125
(°C)
Ambient Temperature
Figure 3.Derating Curve for RT8250 Package
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RT8250
Table 2. Suggested Inductors for Typical Application Circuit
Component Supplier
TDK
Series
Dimensions (mm)
10 x 9.7 x 4.5
8x8x4
VLF10045
NR8040
TAIYO YUDEN
Table 3. Suggested Capacitors for CIN and COUT
Component Supplier
MURATA
TDK
Part No.
Capacitance (μF)
Case Size
1206
GRM31CR61E106K
C3225X5R1E106K
TMK316BJ106ML
GRM31CR60J476M
C3225X5R0J476M
EMK325BJ476MM
GRM32ER71C226M
C3225X5R1C226M
10
10
10
47
47
47
22
22
1206
TAIYO YUDEN
MURATA
TDK
1206
1206
1210
1210
TAIYO YUDEN
MURATA
TDK
1210
1210
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RT8250
Outline Dimension
H
A
Y
M
EXPOSED THERMAL PAD
(Bottom of Package)
J
B
X
F
C
I
D
Dimensions In Millimeters Dimensions In Inches
Symbol
Min
Max
5.004
4.000
1.753
0.510
1.346
0.254
0.152
6.200
1.270
2.300
2.300
2.500
3.500
Min
Max
A
B
C
D
F
H
I
4.801
3.810
1.346
0.330
1.194
0.170
0.000
5.791
0.406
2.000
2.000
2.100
3.000
0.189
0.150
0.053
0.013
0.047
0.007
0.000
0.228
0.016
0.079
0.079
0.083
0.118
0.197
0.157
0.069
0.020
0.053
0.010
0.006
0.244
0.050
0.091
0.091
0.098
0.138
J
M
X
Option 1
Y
X
Y
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
Richtek Technology Corporation
Headquarter
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
5F, No. 95, Minchiuan Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)86672399 Fax: (8862)86672377
Email: marketing@richtek.com
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
www.richtek.com
12
DS8250-05 March 2011
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