RT8289
®
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Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
Ordering Information
Pin Configurations
(TOP VIEW)
Note :
Richtek products are :
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.
5A, 32V, 500kHz Step-Down Converter
Applications
Distributive Power Systems
LCD TV
DSL Modems
Pre-regulator for Linear Regulators
Battery Charger
Typical Application Circuit
SOP-8 (Exposed Pad)
General Description
The RT8289 is a step-down regulator with an internal Power
MOSFET. It achieves 5A of continuous output current over
a wide input supply range with excellent load and line
regulation. Current mode operation provides fast transient
response and eases loop stabilization.
The RT8289 provides protections such as cycle-by-cycle
current limiting and thermal shutdown. In shutdown mode,
the regulator draws 25μA of supply current.
The RT8289 requires a minimum number of external
components, to provide a compact solution.
The RT8289 is available in a SOP-8 (Exposed Pad)
package.
BOOT
NC
NC
FB
SW
VIN
EN
GND
GND
2
3
45
6
7
8
9
Features
High Output Current up to 5A
Internal Soft-Start
100mΩΩ
ΩΩ
Ω Internal Power MOSFET Switch
Internal Compensation Minimizes External Parts
Count
High Efficiency up to 90%
25μμ
μμ
μA Shutdown Current
Fixed 500kHz Frequency
Thermal Shutdown Protection
Cycle-by-Cycle Over Current Protection
Wide 5.5V to 32V Operating Input Range
Adjustable Output Voltage from 1.222V to 26V
Available in an SOP-8 (Exposed Pad) Package
RoHS Compliant and Halogen Free
5V/5A
VIN
EN
GND
BOOT
FB
SW
5
4
7
8
1
L
10µH
10nF
47µFx2
R1
10k
R2
3.16k
VOUT
4.7µF x 2
Chip Enable
VIN
5.5V to 32V RT8289
D
B550C
6, Exposed Pad (9)
CBOOT
COUT
CIN
Open
= Automatic Startup
(POSCAP)
Package Type
SP : SOP-8 (Exposed Pad-Option 1)
RT8289
Lead Plating System
G : Green (Halogen Free and Pb Free)
RT8289GSP : Product Number
YMDNN : Date Code
RT8289
GSPYMDNN
Marking Information
RT8289
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Functional Pin Description
Function Block Diagram
Pin No. Pin Name Pin Funct ion
1 BOOT
High Side Gate Drive Bootstrap Input. BOOT supplies the drive for the high side
N-MOSFET switch. Connect a 10nF or greater capacitor from SW to BOOT to
power the high side switch.
2, 3 NC No Internal Connection.
4 FB
Feedback Input. FB senses the output voltage to regulate said voltage. Drive FB
with a resistive voltage divider from the output voltage. The value of the divider
resistors also sets loop bandwidth. The feedback threshold is 1.222V.
5 EN
Chip Enable (Active High). EN is a digital input that turns the regulator on or off.
Drive EN higher than 1.4V to turn on the regulator, lower than 0.4V to turn it off.
For automatic startup, leave EN unconnected.
6,
9 (Exposed Pad) GND Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
7 VIN
Power Input. VIN supplies the power to the IC, as well as the step-down
converter switches. Drive VIN with a 5.5V to 32V power source. Bypass VIN to
GND with a suitably large capacitor to eliminate noise on the input to the IC.
8 SW
Power Switching Output. SW is the switching node that supplies power to the
output. Connect the output LC filter from SW to the output load. Note that a
capacitor is required from SW to BOOT to power the high side switch.
S
Q
R
Driver
Bootstrap
Control
-
+
Current Sense
Amplifier
PWM
Comparator
Oscillator
500kHz
Ramp
Generator
Regulator
Reference +
-
12k
Error
Amplifier
30pF
400k
13pF
SW
BOOT
FB
EN
VIN
GND
+
-
OC Limit
Clamp
RT8289
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Electrical Characteristics
Parameter Symbol Test Conditions Min Typ Max Unit
Feedback Reference Voltage VFB 5.5V ≦ VIN ≦ 32V 1.202 1.222 1.239 V
High Side Switch-On Resistance RDS(ON)1 -- 100 -- m
Low Side Switch-On Resistance RDS(ON)2 -- 10 --
Upper Switch Leakage VEN = 0V, VSW = 0V -- 0 10 A
Current Limit ILIM Duty = 90%; VBOOTSW = 4.8V -- 6.8 -- A
Current Sense Transconductance GCS Output Current to VCOMP -- 5.5 -- A/V
Oscillator Frequency fSW -- 500 -- kHz
Short Circuit Oscillation Frequency VFB = 0V -- 120 -- kHz
Maximum Duty Cycle DMAX V
FB = 1V -- 90 -- %
Minimum On-Time tON -- 100 -- ns
Under Voltage Lockout Threshold
Rising -- 4.2 -- V
Under Voltage Lockout Threshold
Hysteresis -- 200 -- mV
Logic Low Voltage VIL -- -- 0.4
En Threshold Logic High Voltage VIH 1.4 -- 5.5
V
Enable Pull Up Current -- 1 -- A
(VIN = 12V, TA = 25°C unless otherwise specified)
Absolute Maximum Ratings (Note 1)
Supply Voltage, VIN ------------------------------------------------------------------------------------------ 0.3V to 34V
Switching Voltage, SW (Note 2) ------------------------------------------------------------------------ −0.6V to (VIN + 0.3V)
BOOT Voltage ------------------------------------------------------------------------------------------------- (VSW − 0.3V) to (VSW + 6V)
Other Pins Voltage ------------------------------------------------------------------------------------------- −0.3V to 6V
Power Dissipation, PD @ TA = 25°C
SOP-8 (Exposed Pad) -------------------------------------------------------------------------------------- 1.333W
Package Thermal Resistance (Note 3)
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 4)
HBM (Human Body Model) --------------------------------------------------------------------------------- 2kV
MM (Machine Model) ---------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 5)
Supply Voltage, VIN ------------------------------------------------------------------------------------------ 5.5V to 32V
Enable Voltage, VEN ----------------------------------------------------------------------------------------- 0V to 5.5V
Junction Temperature Range ------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------- −40°C to 85°C
RT8289
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Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and 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 may
affect device reliability.
Note 2. The low side MOSFET body diode forward current must be lower than 1mA
Note 3. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is
measured at the exposed pad of the package.
Note 4. Devices are ESD sensitive. Handling precaution is recommended.
Note 5. The device is not guaranteed to function outside its operating conditions.
Parameter Symbol Test Conditions Min Typ Max Unit
Shutdown Current ISHDN V
EN = 0V -- 25 -- A
Quiescent Current IQ V
EN = 2V, VFB = 1.5V -- 0.8 1 mA
Soft-Start Period -- 4 -- ms
Thermal Shutdown TSD -- 150 -- C
RT8289
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Output Voltage v s . Output Current
4.980
4.984
4.988
4.992
4.996
5.000
5.004
5.008
012345
Output Current (A)
Output Voltage (V)
Efficiency vs. Output Current
0
10
20
30
40
50
60
70
80
90
100
012345
Output Current (A)
Efficiency (%)
Typical Operating Characteristics
VIN = 8V
VIN = 12V
VIN = 24V
VIN = 32V
VOUT = 5V
VIN = 32V
VIN = 24V
VIN = 12V
VOUT = 5V
Frequency vs. Te m pe rature
450
460
470
480
490
500
510
520
530
540
550
-50 -25 0 25 50 75 100 125
Temperature (°C)
Frequency (kHz) 1
VIN = 8V
VIN = 12V
VIN = 24V
VIN = 32V
VOUT = 5V, IOUT = 0A
Frequency vs. Input Voltage
450
460
470
480
490
500
510
520
530
540
550
4 8 12 16 20 24 28 32
Input Voltage (V)
Frequency (kHz) 1
VOUT = 5V, IOUT = 0A
Reference Voltage vs. Temperature
1.210
1.212
1.214
1.216
1.218
1.220
1.222
1.224
1.226
1.228
1.230
-50 -25 0 25 50 75 100 125
Temperature (°C)
Reference Voltage (V)
IOUT = 0A
VIN = 8V
VIN = 12V
VIN = 24V
VIN = 32V
Reference Voltage vs. Input Voltage
1.210
1.212
1.214
1.216
1.218
1.220
1.222
1.224
1.226
1.228
1.230
4 8 12 16 20 24 28 32
Input Voltage (V)
Reference Voltage (V)
IOUT = 0A
RT8289
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Time (100μs/Div)
Load Transient Response
VOUT
(200mV/Div)
IOUT
(2A/Div) VIN = 12V, VOUT = 5V, IOUT = 0.2A to 5A
Switching
Time (1μs/Div)
IL
(5A/Div)
VSW
(20V/Div)
VOUT
(10mV/Div)
VIN = 12V, VOUT = 5V, IOUT = 5A
Load Transient Response
Time (100μs/Div)
IOUT
(2A/Div)
VOUT
(200mV/Div)
VIN = 12V, VOUT = 5V, IOUT = 2.5A to 5A
Current Limit vs. Temperature
5
6
7
8
9
10
11
12
-50 -25 0 25 50 75 100 125
Temperature (°C)
Current Limit (A)
VIN = 12V, VOUT = 2.5V
Shutdown Current vs . Input Voltage
0
10
20
30
40
50
60
4 8 12 16 20 24 28 32
Input Voltage (V)
Shutdown Current (μA) 1
VEN = 0V
Quiescent Current vs. Temperature
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
-50 -25 0 25 50 75 100 125
Temperature (°C)
Quiescent Current (mA
)
VIN = 8V
VIN = 12V
VIN = 24V
VIN = 32V
RT8289
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Power On from EN
Time (2.5ms/Div)
VEN
(5V/Div)
VOUT
(5V/Div)
IL
(5A/Div)
VIN = 12V, VOUT = 5V, IOUT = 5A
Power Off from EN
Time (2.5ms/Div)
VIN = 12V, VOUT = 5V, IOUT = 5A
VEN
(5V/Div)
VOUT
(5V/Div)
IL
(5A/Div)
RT8289
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Application Information
The RT8289 is an asynchronous high voltage buck
converter that can support the input voltage range from
5.5V to 32V and the output current can be up to 5A.
Output Voltage Setting
The resistive divider allows the FB pin to sense the output
voltage as shown in Figure 1.
Figure 1. Output Voltage Setting
The output voltage is set by an external resistive divider
according to the following equation :
OUT FB R1
V = V1
R2
Where VFB is the feedback reference voltage (1.222V typ.).
Where R1 = 10kΩ.
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.
It is recommended to add an external bootstrap diode
between an external 5V and 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 IN4148 or BAT54. The external 5V
can be a 5V fixed input from system or a 5V output of the
RT8289.
Figure 2. External Bootstrap Diode
Soft-Start
The RT8289 contains an internal soft-start clamp that
gradually raises the output voltage. The typical soft-start
time is 4ms.
Chip Enable Operation
The EN pin is the chip enable input. Pull the EN pin low
(<0.4V) will shutdown the device. During shutdown mode,
the RT8289 quiescent current drops to lower than 25μA.
Drive the EN pin to high (>1.4V, < 5.5V) will turn on the
device again. If the EN pin is open, it will be pulled to high
by internal circuit. For external timing control (e.g.RC),the
EN pin can also be externally pulled to High by adding a
100kΩ or greater resistor from the VIN pin (see Figure 3).
Inductor Selection
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.
RT8289
GND
FB
R1
R2
VOUT
SW
BOOT
5V
RT8289 10nF
OUT OUT
LIN
VV
I = 1
fL V
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.
For the ripple current selection, the value of ΔIL = 0.2 (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 :
OUT OUT
L(MAX) IN(MAX)
VV
L = 1
fI V
The inductor's current rating (caused a 40°C temperature
rising from 25°C ambient) should be greater than the
maximum load current and its saturation current should
be greater than the short circuit peak current limit. Please
see Table 2 for the inductor selection reference.
RT8289
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Checking Tran sient Re spon se
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
OUT IN
RMS OUT(MAX) IN OUT
VV
I = I 1
VV
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, two 4.7μF low ESR ceramic
capacitors are recommended. For the recommended
capacitor, please refer to table 3 for more detail.
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.
OUT L OUT
1
VIESR
8fC
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.
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.
Diode Selection
When the power switch turns off, the path for the current
is through the diode connected between the switch output
and ground. This forward biased diode must have a
minimum voltage drop and recovery times. Schottky diode
is recommended and it should be able to handle those
current. The reverse voltage rating of the diode should be
greater than the maximum input voltage, and current rating
should be greater than the maximum load current. For
more detail please refer to Table 4.
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 :
Table 2. Suggested Inductors for Typical
Application Circuit
Component
Supplier Series Dimensions
(mm)
TAIYO
YUDEN NR10050 10 x 9.8 x 5
TDK SLF12565 12.5 x 12.5 x 6.5
The output ripple, ΔVOUT , is determined by :
RT8289
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Figure 3. Reference Circuit with Snubber and Enable Timing Control
recovery time, VOUT can be monitored for overshoot or
ringing that would indicate a stability problem.
EMI Consideration
Since parasitic inductance and capacitance effects in PCB
circuitry would cause a spike voltage on SW pin when
high side MOSFET is turned-on/off, this spike voltage on
SW may impact on EMI performance in the system. In
order to enhance EMI performance, there are two methods
to suppress the spike voltage. One is to place an R-C
snubber between SW and GND and make them as close
as possible to the SW pin (see Figure 3). Another method
is to add a resistor in series with the bootstrap
capacitor, CBOOT. But this method will decrease the driving
capability to the high side MOSFET. It is strongly
recommended to reserve the R-C snubber during PCB
layout for EMI improvement. Moreover, reducing the SW
trace area and keeping the main power in a small loop will
be helpful on EMI performance. For detailed PCB layout
guide, please refer to the section of Layout Consideration.
Thermal Considerations
For continuous operation, do not exceed the maximum
operation junction temperature. 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 :
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.
For recommended operating conditions specification of
RT8289, the maximum junction temperature is 125°C. The
junction to ambient thermal resistance θJA is layout
dependent. For PSOP-8 package, the thermal resistance
θJA is 75°C/W on the standard JEDEC 51-7 four-layers
thermal test board. The maximum power dissipation at
TA = 25°C can be calculated by following formula:
PD(MAX) = (125°C − 25°C) / (75°C/W) = 1.333W
(min.copper area PCB layout)
PD(MAX) = (125°C − 25°C) / (49°C/W) = 2.04W (70mm2
copper area PCB layout)
The thermal resistance θJA of SOP-8 (Exposed Pad) is
determined by the package architecture design and the
PCB layout design. However, the package architecture
design had been designed. If possible, it's useful to
increase thermal performance by the PCB layout copper
design. The thermal resistance θJA can be decreased by
adding copper area under the exposed pad of SOP-8
(Exposed Pad) package.
As shown in Figure 4, the amount of copper area to which
the SOP-8 (Exposed Pad) is mounted affects thermal
performance. When mounted to the standard
SOP-8 (Exposed Pad) pad (Figure 4a), θJA is 75°C/W.
Adding copper area of pad under the SOP-8 (Exposed
Pad) (Figure 4.b) reduces the θJA to 64°C/W. Even further,
increasing the copper area of pad to 70mm2 (Figure 4.e)
reduces the θJA to 49°C/W.
VIN
EN
GND
BOOT
FB
SW
5
4
7
8
1
L
10µH
10nF
R1
10k
R2
3.16k
VOUT
5V/5A
4.7µF x 2
VIN
5.5V to 32V RT8289
D
B550C
6, Exposed Pad (9)
CBOOT
COUT
CIN
RBOOT*
RS*
CS*
REN*
CEN*
* : Optional
47µFx2
(POSCAP)
RT8289
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Layout Consideration
Follow the PCB layout guidelines for optimal performance
of the RT8289.
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 (VIN and GND).
LX node is with high frequency voltage swing and should
be kept at small area. Keep analog components away
from the LX node to prevent stray capacitive noise pick-
up.
Connect feedback network behind the output capacitors.
Keep the loop area small. Place the feedback
components near the RT8289.
Connect all analog grounds to a command node and
then connect the command node to the power ground
behind the output capacitors.
An example of PCB layout guide is shown in Figure 6 for
reference.
(a) Copper Area = (2.3 x 2.3) mm2, θJA = 75°C/W
(b) Copper Area = 10mm2, θJA = 64°C/W
(c) Copper Area = 30mm2 , θJA = 54°C/W
(d) Copper Area = 50mm2 , θJA = 51°C/W
(e) Copper Area = 70mm2 , θJA = 49°C/W
Figure 4. Thermal Resistance vs. Copper Area Layout
Design
Figure 5. Derating Curves for RT8289 Package
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
0 255075100125
Ambient Temperature
P
ower
Di
ss
i
pat
i
on
(W)
(°C)
Copper Area
70mm2
50mm2
30mm2
10mm2
Min.Layout
Four Layer PCB
The maximum power dissipation depends on operating
ambient temperature for fixed TJ (MAX) and thermal
resistance θJA. For the RT8289, the Figure 5 of derating
curves allows the designer to see the effect of rising
ambient temperature on the maximum power dissipation
allowed.
RT8289
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Figure 6. PCB Layout Guide
Table 3. Suggested Capacitors for CIN and COUT
Component Supplier Series VRRM (V) IOUT (A) Package
DIODES B550C 50 5 SMC
PANJIT SK55 50 5 SMC
Table 4. Suggested Diode
Location Component Supplier Part No. Capacitance (F) Case S ize
CIN MURATA GRM32ER71H475K 4.7 1206
CIN T AIYO YUDEN UMK325BJ475MM-T 4.7 1206
COUT SANYO 16IQC47M 47 D2
COUT SANYO 10TPE47MAIB 47 B2
COUT MURATA GRM31CR60J476M 47 1206
BOOT
NC
NC
FB
SW
VIN
EN
GND
GND
2
3
45
6
7
8
9CIN
VOUT
GND
VOUT R1
R2
SW
CBOOT
D1
The feedback components
should be connected as close
to the device as possible.
SW should be connected to inductor by
wide and short trace. Keep sensitive
components away from this trace.
L
COUT
CIN
COUT
Input capacitor should be
placed as close to the IC
as possible.
RT8289
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Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek 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 Richtek or its subsidiaries.
Outline Dimension
A
B
J
F
H
M
C
D
I
Y
X
EXPOSED THERMAL PAD
(Bottom of Package)
8-Lead SOP (Exposed Pad) Plastic Package
Dimensions In Millimeters Dimensions In Inches
Symbol Min Max Min Max
A 4.801 5.004 0.189 0.197
B 3.810 4.000 0.150 0.157
C 1.346 1.753 0.053 0.069
D 0.330 0.510 0.013 0.020
F 1.194 1.346 0.047 0.053
H 0.170 0.254 0.007 0.010
I 0.000 0.152 0.000 0.006
J 5.791 6.200 0.228 0.244
M 0.406 1.270 0.016 0.050
X 2.000 2.300 0.079 0.091
Option 1
Y 2.000 2.300 0.079 0.091
X 2.100 2.500 0.083 0.098
Option 2
Y 3.000 3.500 0.118 0.138
