RT9183

Ultra Low Dropout 1.5A Linear Regulator

General Description Features
The RT9183 series are high performance linear voltage z 330mV Dropout @ 1.5A
regulators that provide ultra low-dropout voltage, high output z μA Low Ground Pin Current
380μ
current with low ground current. It operates from an input z Excellent Line and Load Regulation
of 2.3V to 5.5V and provides output current up to 1.5A z μA Quiescent Current in Shutdown Mode
0.1μ
thus is suitable to drive digital circuits requiring low voltage z Guaranteed 1.5A Output Current
at high currents. z Fixed Output Voltages : 1.2V, 1.8V, 2.5V, 3.3V
z Adjustable Output Voltage from 0.8V to 4.5V
The RT9183 has superior regulation over variations in line
z Over-Temperature/Over-Current Protection
and load. Also it provides fast respond to step changes in
z RoHS Compliant and 100% Lead (Pb)-Free
load. Other features include over-current and over-
temperature protection. The adjustable version has enable
Applications
pin to reduce power consumption in shutdown mode.
z Battery-Powered Equipment
The devices are available in fixed output voltages of 1.2V, z Mother Board/Graphic Card
1.8V, 2.5V, 3.3V and as an adjustable device with a 0.8V z Peripheral Cards
reference voltage. The RT9183 regulators are available in z PCMCIA Card
3-lead SOT-223 and TO-263 packages (fixed output only
for the 3-lead option). Also available are 5-lead TO-263 Pin Configurations
and fused SOP-8 packages with two external resistors to (TOP VIEW)
set the output voltage ranges from 0.8V to 4.5V.

Ordering Information
RT9183 - 1 2 3 1 2 3

Package Type
G : SOT-223 VIN GND VOUT GND VOUT VIN
GF : SOT-223 (F-Type) (TAB) (TAB)

S : SOP-8 SOT-223 SOT-223 (F-Type)

M : TO-263
M5 : TO-263-5
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Output Voltage 1 2 3 4 5
1 2 3
Defauit : Adjustable
12 : 1.2V
18 : 1.8V
25 : 2.5V
33 : 3.3V VIN EN VIN VOUT ADJ
VOUT
H : Chip Enable High GND(TAB) GND(TAB)
L : Chip Enable Low TO-263-5
TO-263
Note :
RichTek Pb-free and Green products are : EN 8 GND
`RoHS compliant and compatible with the current require- VIN 2 7 GND
VOUT 3 6 GND
ments of IPC/JEDEC J-STD-020.
ADJ 4 5 GND
`Suitable for use in SnPb or Pb-free soldering processes.
`100%matte tin (Sn) plating. SOP-8

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RT9183
Typical Application Circuit

(SOT-223 & TO-263)

RT9183
VOUT
VIN = 3.3V VIN VOUT
2.5V, 1.5A
CIN GND COUT
10uF 10uF

Figure 1. 3.3V to 2.5V Regulator

(SOP-8 & TO-263-5)

RT9183
VIN VIN VOUT VOUT
R1
Enable EN ADJ COUT
CIN GND
C 10uF
10uF R2
0.1uF

R1 Note: The value of R2 should be less

VOUT = 0.8 × (1 + )Volts
R2 than 80k to maintain
regulation.
Figure 2. Adjustable Operation

(SOP-8 & TO-263-5)

RT9183
VIN VIN VOUT VOUT

COUT
Enable EN GND ADJ
C CIN 10uF
0.1uF 10uF

Figure 3. Fixed Operation with SOP-8 and TO-263-5 packages

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 RT9183
Functional Pin Description
Pin Name Pin Function

Chip Enable Control Input.

EN
Note that the device will be in the unstable state if the pin is not connected.
VIN Supply Input

GND Common Ground

VOUT Regulator Output

The output voltage is set by the internal feedback resistors when this pin
ADJ grounded. If external feedback resistors are applied, the output voltage will be:
VOUT = 0.8 × (1 + R1 ) Volts
R2

Function Block Diagram

VIN
Current Limit
Sensor
+
Error
-
Amplifier
0.8V
-
Reference
+
VOUT
Shutdown Thermal
EN
Logic Shutdown

ADJ
-
+
100mV
Output Mode
GND
Comparator

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RT9183
Absolute Maximum Ratings (Note 1)
z Supply Input Voltage ------------------------------------------------------------------------------------------------------ 6V
z Package Thermal Resistance
SOT-223, θJA ---------------------------------------------------------------------------------------------------------------- 115°C/W
SOT-223, θJC --------------------------------------------------------------------------------------------------------------- 15°C/W
SOT-223 (F-Type), θJA ---------------------------------------------------------------------------------------------------- 135°C/W
SOT-223 (F-Type), θJC ---------------------------------------------------------------------------------------------------- 17°C/W
SOP-8, θJA ------------------------------------------------------------------------------------------------------------------ 125°C/W
SOP-8, θJC ------------------------------------------------------------------------------------------------------------------ 20°C/W
TO-263, θJA ----------------------------------------------------------------------------------------------------------------- 45°C/W
TO-263, θJC ----------------------------------------------------------------------------------------------------------------- 8°C/W
z Power Dissipation, PD@TA = 25°C
SOT-223 --------------------------------------------------------------------------------------------------------------------- 0.87W
SOT-223 (F-Type) ---------------------------------------------------------------------------------------------------------- 0.74W
SOP-8 ------------------------------------------------------------------------------------------------------------------------ 0.8W
TO-263 ----------------------------------------------------------------------------------------------------------------------- 2.22W
z Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------- 260°C
z Junction Temperature ----------------------------------------------------------------------------------------------------- 150°C
z Storage Temperature Range -------------------------------------------------------------------------------------------- −65°C to 150°C
z ESD Susceptibility (Note 2)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------------ 200V

Recommended Operating Conditions (Note 3)

z Supply Input Voltage ------------------------------------------------------------------------------------------------------ 2.3V to 5.5V
z Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C

Electrical Characteristics
(VIN = VOUT + 0.7V, CIN =COUT = 10μF (Ceramic), TA = 25°C unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Units

Output Voltage Accuracy

ΔV OUT IOUT = 10mA −2 0 +2 %
(Fixed Output Voltage)

Output Voltage Range (Adjustable) VOUT_ADJ 0.8 -- 4.5 V

Quiescent Current (Note 6) IQ IOUT = 0mA, Enable -- 380 500 μA
Standby Current (Note 7) ISTBY V IN = 5.5V, Shutdown -- 0.1 1 μA
Current Limit ILIM 2 3.2 4.2 A
IOUT = 0.5A -- 110 300
Dropout Voltage (Note 4) VDROP IOUT = 1.0A -- 220 400 mV
IOUT = 1.5A -- 330 500
V OUT + 0.7V < VIN < 5.5V
Line Regulation ΔV LINE -- 0.035 0.18 %/V
IOUT = 10mA

To be continued

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 RT9183
Parameter Symbol Test Conditions Min Typ Max Units

Load Regulation (Note 5)

ΔVLOAD 1mA < IOUT < 1.5A -- 22 45 mV
(Fixed Output Voltage)

Thermal Shutdown Temperature TSD -- 170 -- °C

Thermal Shutdown Hysteresis ΔTSD -- 30 -- °C
Logic-Low Voltage VIL VIN = 5.5V -- -- 0.6
EN Threshold V
Logic-High Voltage VIH VIN = 5.5V 1.8 -- --
Enable Pin Current IEN VIN = 5.5V, Enable -- 0.1 1 μA
ADJ
Reference Voltage Tolerance VREF 0.784 0.8 0.816 V
Adjust Pin Current IADJ VADJ = VREF -- 10 100 nA
Adjust Pin Threshold VTH(ADJ) 0.05 0.1 0.2 V

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. Devices are ESD sensitive. Handling precaution recommended.
Note 3. The device is not guaranteed to function outside its operating conditions.
Note 4. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 5. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are tested for
load regulation in the load range from 10mA to 1.5A.
Note 6. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT
under no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus
the ground pin current.
Note 7. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown
signal (VEN >1.8V ). It is measured with VIN = 5.5V.
Note 8. θJA is measured in natural convection (still air) at TA = 25°C with the component mounted on a low effective
thermal conductivity test board of JEDEC 51-3 thermal measurement standard. And the cooper area of PCB
layout is 4mm x 2.5mm on SOT-223, 14mm x 14mm on TO-263 for thermal measurement.

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RT9183
Typical Operating Characteristics
Output Voltage vs. Temperature Output Voltage vs. Temperature
1.9 2.6
VIN = 5V, RL = ∞ VIN = 5V, RL = ∞
CIN = COUT = 10uF (Ceramic,Y5V) CIN = COUT = 10uF (Ceramic,Y5V)

1.85 2.55
Output Voltage (V)

Output Voltage (V)

1.8 2.5

1.75 2.45

RT9183H-18CS RT9183-25CG
1.7 2.4
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
Temperature (°C) Temperature (°C)

Quiescent Current vs. Temperature Quiescent Current vs. Temperature

400 400
Quiescent Current (uA) 1
Quiescent Current (uA) 1

380 380

360 360

340 340

320 VIN = 5V, RL = ∞ 320 VIN = 5V, RL = ∞

CIN = COUT = 10uF CIN = COUT = 10uF
(Ceramic,Y5V) RT9183H-18CS (Ceramic,Y5V) RT9183-25CG
300 300
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
Temperature (°C) Temperature (°C)

Current Limit vs. Temperature Current Limit vs. Temperature

4 4
VIN = 5V, CIN = COUT = 10uF(Ceramic,Y5V) VIN = 5V, CIN = COUT = 10uF(Ceramic,Y5V)

3.8 3.8
Current Limit (A)

Current Limit (A)

3.6 3.6

3.4 3.4

3.2 3.2

RT9183-25CG RT9183L-33CM5
3 3
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
Temperature (°C) Temperature (°C)

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 RT9183

Dropout vs.
Dropout Voltage Voltage
Load Current Dropout Voltage
Dropoutvs. Load Current
Voltage
500 500

TJ = 125°C
TJ = 125°C
Dropout Voltage (mV) 1

400 400

Dropout Voltage (mV)

300 300
TJ = +25°C TJ = +25°C

200 200

TJ = -40°C TJ = -40°C
100 100

RT9183-25CG RT9183L-33CM5
0 0
0 0.3 0.6 0.9 1.2 1.5 0 0.3 0.6 0.9 1.2 1.5
Load Current (A) Load Current (A)

Dropout Voltage vs. Load Current Load Transient Response

400
RT9183H-CS COUT = 47uF/Low ESR, ILOAD = 1mA to 750mA
VOUT = 3.3V TJ= 125°C
Current (A)

1
Load
Dropout Voltage (mV)

300 0.5
TJ= 25°C
0

200
Output Voltage
Deviation(mV)

20
TJ= -40°C
100 0

-20
RT9183H-18CS
0
0 0.3 0.6 0.9 1.2 1.5
Time (100us/Div)
Load Current (A)

Load Transient Response Load Transient Regulation

RT9183-12CGF
Output Voltage

COUT = 47uF/Low ESR, ILOAD = 1mA to 1.5A

Deviation(mV)

2 20
Current (A)
Load

1 0

50
Load Current (mA)
Output Voltage
Deviation(mV)

0 500
-50 0

RT9183H-18CS ILOAD = 1mA to 750mA COUT = 47uF/Low ESR

Time (100us/Div) Time (100us/Div)

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RT9183

Line Transient Regulation Line Transient Response

Input Voltage
Deviation(V)
ILOAD = 100mA COUT = 47uF/Low ESR COUT = 47uF/Low ESR, ILOAD = 100mA
Input Voltage
Deviation(V)

5 4

Output Voltage
Deviation(mV)
10
Output Voltage
Deviation(mV)

10 0

0 -10

RT9183-12CGF RT9183H-18CS

Time (100us/Div) Time (100us/Div)

EN Pin Shutdown Threshold vs. Temperature EN Pin Shutdown Response

1.1
Shutdown Threshold Voltage (V) 1

CIN = COUT = 10uF (Ceramic,Y5V)

Voltage (V)

ILOAD = 100mA, VIN = 5V, TA =25°C

EN

1 5

VOUT Off to On 0

0.9
Voltage (V)

2
VOUT On to Off
Output

0.8 1

0
RT9183L-33CM5 RT9183H-18CS
0.7
-50 -25 0 25 50 75 100 125
Time (500us/Div)
Temperature (°C)

Reference Voltage vs. Temperature

0.85
VIN = 5V,CIN = COUT = 10uF (Electrolysis)

0.83
Reference Voltage (V)

0.81

0.79

0.77

RT9183H-CS
0.75
-50 -25 0 25 50 75 100 125
Temperature (°C)

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 RT9183
Application Information
Like any low-dropout regulator, the RT9183 series requires No Load Stability
input and output decoupling capacitors. These capacitors The device will remain stable and in regulation with no
must be correctly selected for good performance (see external load. This is specially important in CMOS RAM
Capacitor Characteristics Section). Please note that linear keep-alive applications.
regulators with a low dropout voltage have high internal
Input-Output (Dropout) Voltage
loop gains which require care in guarding against
A regulator's minimum input-to-output voltage differential
oscillation caused by insufficient decoupling capacitance.
(dropout voltage) determines the lowest usable supply
Input Capacitor voltage. In battery-powered systems, this determines the
An input capacitance of ≅10μF is required between the useful end-of-life battery voltage. Because the device uses
device input pin and ground directly (the amount of the a PMOS, its dropout voltage is a function of drain-to-source
capacitance may be increased without limit). The input on-resistance, RDS(ON), multiplied by the load current:
capacitor MUST be located less than 1 cm from the device VDROPOUT = VIN - VOUT = RDS(ON) × IOUT
to assure input stability (see PCB Layout Section). A lower
ESR capacitor allows the use of less capacitance, while Current Limit
higher ESR type (like aluminum electrolytic) require more The RT9183 monitors and controls the PMOS' gate
capacitance. voltage, minimum limiting the output current to 2A . The
output can be shorted to ground for an indefinite period of
Capacitor types (aluminum, ceramic and tantalum) can be
time without damaging the part.
mixed in parallel, but the total equivalent input capacitance/
ESR must be defined as above to stable operation. Short-Circuit Protection
There are no requirements for the ESR on the input The device is short circuit protected and in the event of a
capacitor, but tolerance and temperature coefficient must peak over-current condition, the short-circuit control loop
be considered when selecting the capacitor to ensure the will rapidly drive the output PMOS pass element off. Once
capacitance will be ≅10μF over the entire operating the power pass element shuts down, the control loop will
temperature range. rapidly cycle the output on and off until the average power
dissipation causes the thermal shutdown circuit to respond
Output Capacitor
to servo the on/off cycling to a lower frequency. Please
The RT9183 is designed specifically to work with very refer to the section on thermal information for power
small ceramic output capacitors. The recommended dissipation calculations.
minimum capacitance (temperature characteristics X7R or
X5R) are 10μF to 47μF range with 10mΩ to 25mΩ range Capaacitor Characteristics
ceramic capacitors between each LDO output and GND for It is important to note that capacitance tolerance and
transient stability, but it may be increased without limit. variation with temperature must be taken into consideration
Higher capacitance values help to improve transient. when selecting a capacitor so that the minimum required
The output capacitor's ESR is critical because it forms a amount of capacitance is provided over the full operating
zero to provide phase lead which is required for loop temperature range. In general, a good tantalum capacitor
stability. will show very little capacitance variation with temperature,
but a ceramic may not be as good (depending on dielectric
type). Aluminum electrolytics also typically have large
temperature variation of capacitance value.

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RT9183
Equally important to consider is a capacitor's ESR change The increasing ESR at lower temperatures can cause
with temperature: this is not an issue with ceramics, as oscillations when marginal quality capacitors are used (if
their ESR is extremely low. However, it is very important the ESR of the capacitor is near the upper limit of the
in tantalum and aluminum electrolytic capacitors. Both stability range at room temperature).
show increasing ESR at colder temperatures, but the
increase in aluminum electrolytic capacitors is so severe Aluminum:
they may not be feasible for some applications. This capacitor type offers the most capacitance for the
money. The disadvantages are that they are larger in
Ceramic: physical size, not widely available in surface mount, and
For values of capacitance in the 10μF to 100μF range, have poor AC performance (especially at higher
ceramics are usually larger and more costly than tantalums frequencies) due to higher ESR and ESL.
but give superior AC performance for by-passing high
Compared by size, the ESR of an aluminum electrolytic is
frequency noise because of very low ESR (typically less
higher than either Tantalum or ceramic, and it also varies
than 10mΩ). However, some dielectric types do not have
greatly with temperature. A typical aluminum electrolytic
good capacitance characteristics as a function of voltage
can exhibit an ESR increase of as much as 50X when going
and temperature.
from 25°C down to -40°C.
Z5U and Y5V dielectric ceramics have capacitance that It should also be noted that many aluminum electrolytics
drops severely with applied voltage. A typical Z5U or Y5V only specify impedance at a frequency of 120Hz, which
capacitor can lose 60% of its rated capacitance with half indicates they have poor high frequency performance. Only
of the rated voltage applied to it. The Z5U and Y5V also aluminum electrolytics that have an impedance specified
exhibit a severe temperature effect, losing more than 50% at a higher frequency (between 20kHz and 100kHz) should
of nominal capacitance at high and low limits of the be used for the device. Derating must be applied to the
temperature range. manufacturer's ESR specification, since it is typically only
valid at room temperature.
X7R and X5R dielectric ceramic capacitors are strongly
Any applications using aluminum electrolytics should be
recommended if ceramics are used, as they typically
thoroughly tested at the lowest ambient operating
maintain a capacitance range within ± 20% of nominal
temperature where ESR is maximum.
over full operating ratings of temperature and voltage. Of
course, they are typically larger and more costly than Z5U/ Thermal Considerations
Y5U types for a given voltage and capacitance. Thermal protection limits power dissipation in RT9183.
Tantalum: When the operation junction temperature exceeds 170°C,
the OTP circuit starts the thermal shutdown function and
Solid tantalum capacitors are recommended for use on
turns the pass element off. The pass element turns on
the output because their typical ESR is very close to the
again after the junction temperature cools by 30°C.
ideal value required for loop compensation. They also work
well as input capacitors if selected to meet the ESR For continuous operation, do not exceed absolute
requirements previously listed. maximum operation junction temperature 125°C. The
power dissipation definition in device is:
Tantalums also have good temperature stability: a good
quality tantalum will typically show a capacitance value PD = (VIN − VOUT) x IOUT + VIN x IQ
that varies less than 10~15% across the full temperature
range of 125°C to -40°C. ESR will vary only about 2X going
from the high to low temperature limits.

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 RT9183
The maximum power dissipation depends on the thermal Good board layout practices must be used or instability
resistance of IC package, PCB layout, the rate of can be induced because of ground loops and voltage drops.
surroundings airflow and temperature difference between The input and output capacitors MUST be directly
junction to ambient. The maximum power dissipation can connected to the input, output, and ground pins of the
be calculated by following formula: device using traces which have no other currents flowing
PD(MAX) = ( TJ(MAX) - TA ) /θJA through them.

Where T J(MAX) is the maximum operation junction The best way to do this is to layout CIN and COUT near the
temperature 125°C, TA is the ambient temperature and device with short traces to the VIN, VOUT, and ground pins.
the θJA is the junction to ambient thermal resistance. The regulator ground pin should be connected to the
For recommended operating conditions specification of external circuit ground so that the regulator and its
RT9183, where T J(MAX) is the maximum junction capacitors have a“ single point ground” .
temperature of the die (125°C) and TA is the maximum It should be noted that stability problems have been seen
ambient temperature. The junction to ambient thermal in applications where “ vias ” to an internal ground plane
resistance (θJA is layout dependent) for SOT-223 package were used at the ground points of the device and the input
is 115°C/W, SOT-223 package (F-Type) is 135°C/W, and output capacitors. This was caused by varying ground
SOP-8 package is 125°C/W, and TO-263 package is potentials at these nodes resulting from current flowing
45°C/W on standard JEDEC 51-3 thermal test board. through the ground plane. Using a single point ground
The maximum power dissipation depends on operating technique for the regulator and it's capacitors fixed the
ambient temperature for fixed TJ(MAX) and thermal resistance problem. Since high current flows through the traces going
θJA. For RT9183 packages, the Figure 4 of derating curves into VIN and coming from VOUT, Kelvin connect the capacitor
allows the designer to see the effect of rising ambient leads to these pins so there is no voltage drop in series
temperature on the maximum power allowed. with the input and output capacitors.
Optimum performance can only be achieved when the
PCB Layout device is mounted on a PC board according to the diagram
2400 below:
TO-263
Maximum power dissipation (mW)

2000 GND

1600

1200
SOT-223
SOP-8
800
+ ADJ
EN
SOT-223
400
(F-Type)

0 VOUT
0 25 50 75 100 125
(°C)
Ambient temperature (℃)
+

Figure 4
GND VIN
GND

SOP-8 Board Layout

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RT9183
Adjustable Operation
The adjustable version of the RT9183 has an output voltage
range of 0.8V to 4.5V. The output voltage is set by the
ratio of two external resistors as shown in Figure 2. The
value of R2 should be less than 80k to maintain regulation.
In critical applications, small voltage drop is caused by
the resistance (RT) of PC traces between the ground pin of
the device and the return pin of R2 (See Figure 5 shown on
next page). Note that the voltage drop across the external
PC trace will add to the output voltage of the device.
Optimum regulation will be obtained at the point where
the return pin of R2 is connected to the ground pin of the
device directly.

(SOP-8 & TO-263-5)

RT9183
VIN VIN VOUT VOUT

R1
Enable EN ADJ COUT
GND
C CIN 10uF
0.1uF R2
10uF RT

Figure 5. Return Pin of External Resistor Connection

Referring to Figure 3 the fixed voltage versions for both

SOP-8 and TO-263-5 packages, the ADJ pin is the input
to the error amplifier and MUST be tied the ground pin of
the device directly otherwise it will be in the unstable state
if the pin voltage more than 0.1V with respect to the ground
pin itself.

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 RT9183
Outline Dimension

D
D1 H

C B

L
L1

e e

A
A1
b

Dimensions In Millimeters Dimensions In Inches

Symbol
Min Max Min Max
A 1.450 1.803 0.057 0.071
A1 0.020 0.100 0.0008 0.0047
b 0.610 0.787 0.024 0.031
B 3.302 3.708 0.130 0.146
C 6.706 7.290 0.264 0.287
D 6.299 6.706 0.248 0.264
D1 2.896 3.150 0.114 0.124
e 2.261 2.362 0.089 0.093
H 0.229 0.330 0.009 0.013
L 1.550 1.950 0.061 0.077
L1 0.800 1.100 0.009 0.013

3-Lead SOT-223 Surface Mount Package

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RT9183

H
A

J B

C
I
D

Dimensions In Millimeters Dimensions In Inches

Symbol
Min Max Min Max
A 4.801 5.004 0.189 0.197
B 3.810 3.988 0.150 0.157
C 1.346 1.753 0.053 0.069
D 0.330 0.508 0.013 0.020
F 1.194 1.346 0.047 0.053
H 0.170 0.254 0.007 0.010
I 0.050 0.254 0.002 0.010
J 5.791 6.200 0.228 0.244
M 0.400 1.270 0.016 0.050

8-Lead SOP Plastic Package

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 RT9183

C
D U
B

V
E

L1

b1
L2

e b b2

Dimensions In Millimeters Dimensions In Inches

Symbol
Min Max Min Max
A 4.064 4.826 0.160 0.190
B 1.143 1.676 0.045 0.066
b 0.660 0.914 0.026 0.036
b1 1.143 1.397 0.045 0.055
b2 0.305 0.584 0.012 0.023
C 1.143 1.397 0.045 0.055
D 9.652 10.668 0.380 0.420
E 8.128 9.652 0.320 0.380
e 2.286 2.794 0.090 0.110
L1 14.605 15.875 0.575 0.625
L2 2.286 2.794 0.090 0.110
U 6.223 Ref. 0.245 Ref.
V 7.620 Ref. 0.300 Ref.

3-Lead TO- 263 Surface Mount

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RT9183

C
D U
B

V
E

L1

L2

e b
b2

Dimensions In Millimeters Dimensions In Inches

Symbol
Min Max Min Max
A 4.064 4.826 0.160 0.190
B 1.143 1.676 0.045 0.066
b 0.660 0.914 0.026 0.036
b2 0.305 0.584 0.012 0.023
C 1.143 1.397 0.045 0.055
D 9.652 10.668 0.380 0.420
E 8.128 9.652 0.320 0.380
e 1.524 1.829 0.060 0.072
L1 14.605 15.875 0.575 0.625
L2 2.286 2.794 0.090 0.110
U 6.223 Ref. 0.245 Ref.
V 7.620 Ref. 0.300 Ref.

5-Lead TO-263 Plastic Surface Mount Package

Richtek Technology Corporation Richtek Technology Corporation

Headquarter Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com

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