RT9161/A
300/500mA Low Dropout Linear Voltage Regulator
General Description
The RT9161/A is a 300/500mA fixed output voltage low
dropout linear regulator. Typical ground current is
approximately 110μA, from zero to maximum loading
conditions. Wide range of available output voltage fits most
of applications. Built-in output current-limiting most
thermal-limiting provide maximal protection against any
fault conditions.
For ease of application, the RT9161/A comes in the popular
3-pin SOT-23 (300mA), SOT-89 (300mA), SOT-223
(500mA), or TO-92 packages.
Features
Low Dropout Voltage of 200mV at Output Current
100mA, 450mV at Output Current 300mA, and
750mV at 500mA Output Current
Guaranteed 300/500mA Output Current
Internal 1.5Ω P-MOSFET Draws No Base Current
Ω
μ
Low Ground Current 110μA
2% Accuracy Output Voltage
Input Voltage Range up to 12V
Extremely Tight Load Regulation
Fast Transient Response
Current-limiting and Thermal-limiting
RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9161/A-
Package Type
V : SOT-23-3
X : SOT-89
G : SOT-223
ZL : TO-92 (L-Type)
ZT : TO-92 (T-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Output Voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
500mA Output Current
300mA Output Current
Applications
Voltage Regulator for LAN Card, CD-ROM, and DVD
Wireless Communication Systems
Battery Powered Systems
Marking Information
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
Pin Configurations
(TOP VIEW)
VIN
3
1
GND
2
VOUT
1
2
3
Note :
RichTek Pb-free and Green 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.
100%matte tin (Sn) plating.
SOT-23-3
GND
VIN VOUT
(TAB)
SOT-89
1
2
3
GND
VIN VOUT
(TAB)
SOT-223
DS9161/A-31 March 2007
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RT9161/A
3
2
1
VOUT
GND
VIN
3
2
1
VOUT
VIN
GND
TO-92
RT9161/A-
CZL
TO-92
CZT
RT9161/A-
Typical Application Circuit
RT9161/A
V
IN
C
IN
1uF
VIN
VOUT
GND
C
OUT
10uF
V
OUT
+
+
Electrolytic
Functional Pin Description
Pin Name
VOUT
GND
VIN
Pin Function
Output Voltage
Ground
Power Input
Function Block Diagram
VIN
VOUT
Error Amp
-
+
Current
Limiting
Sensor
Thermal
Shutdown
1.2V
Reference
GND
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DS9161/A-31 March 2007
RT9161/A
Absolute Maximum Ratings
Input Voltage -----------------------------------------------------------------------------------------------------------
Operating Junction Temperature Range -------------------------------------------------------------------------
Storage Temperature Range ---------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-3 ---------------------------------------------------------------------------------------------------------------
SOT-89 ------------------------------------------------------------------------------------------------------------------
SOT-223 ----------------------------------------------------------------------------------------------------------------
−
0.3 to 14V
−
40°C to 125°C
−
65°C to 150°C
0.4W
0.571W
0.741W
TO-92 -------------------------------------------------------------------------------------------------------------------- 0.625W
Package Thermal Resistance (Note 4)
SOT-23-3,
θ
JA
---------------------------------------------------------------------------------------------------------- 250°C/W
SOT-23-3,
θ
JC
--------------------------------------------------------------------------------------------------------- 140°C/W
SOT-89,
θ
JA
------------------------------------------------------------------------------------------------------------ 175°C/W
SOT-89,
θ
JC
------------------------------------------------------------------------------------------------------------ 100°C/W
SOT-223,
θ
JA
----------------------------------------------------------------------------------------------------------- 135°C/W
SOT-223,
θ
JC
---------------------------------------------------------------------------------------------------------- 15°C/W
TO-92,
θ
JA
-------------------------------------------------------------------------------------------------------------- 160°C/W
TO-92,
θ
JC
-------------------------------------------------------------------------------------------------------------- 125°C/W
Electrical Characteristics
(T
A
= 25°C, C
IN
= 1μF, C
OUT
= 10μF, unless otherwise specified.)
Parameter
Output Voltage Accuracy
Output Voltage Temperature
Coefficient
Line Regulation
Load Regulation (Note1)
Current Limit
(Note 2)
RT9161
RT9161A
Symbol
ΔV
OUT
Test Conditions
I
L
= 1mA, V
IN
= 5V
Min
-2
--
Typ
--
50
2
1
580
900
110
Max
+2
150
3
30/50
--
--
180
Units
%
PPM/°C
%V
OUT
mV
mA
mV
μA
ΔV
LINE
ΔV
LOAD
I
LIM
V
DROP
I
L
= 1mA, V
IN
= 4.5 ~ 12V
I
L
= 1mA ~ 300/500mA, V
IN
= 5V
V
IN
= 5V, V
OUT
= 0V
I
L
= 300/500mA
--
--
350
500
--
--
Dropout Voltage (Note 3)
Standby Current
450/750 600/1000
I
STANDBY
I
L
= 0, V
IN
= 12V
Note 1.
Regulation is measured at constant junction temperature, using pulsed ON time.
Note 2.
Current Limit is measured at constant junction temperature, using pulsed ON time.
Note 3.
The dropout voltage is defined as V
IN
-V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
−
100mV.
Note 4.
θ
JA
is measured in the natural convection at T
A
= 25°C on a low effective
single layer thermal conductivity test board of
JEDEC 51-3 thermal measurement standard.
DS9161/A-31 March 2007
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RT9161/A
Typical Operating Characteristics
Temperature Stability
3.4
Quiescient Current vs. Temperature
0.14
0.12
Quiescient Current (mA)
Output Voltage (V)
3.2
V
OUT
= 3.3V
0.10
0.08
0.06
0.04
0.02
3
2.8
2.6
V
OUT
= 2.5V
V
IN
= 5V
2.4
-50
-25
0
25
50
75
100
125
0.00
-30
0
30
60
90
120
Temperature
(°C)
Temperature
(°C)
Dropout Voltage (V
IN
-V
OUT
)
1
1.4
Short Circuit Current
125°C
125°C
Short Circuit Current (A)
Dropout Voltage (V)
0.8
1.2
1
0.8
0.6
0.4
0.2
0
25°C
0.6
25°C
0.4
0.2
V
OUT
= 3.3V
0
0
100
200
300
400
500
0
2
4
6
8
10
I
Load
(mA)
Input/Output Differential (V)
Line Transient Response
7
Input Voltage
Deviation (V)
6
5
4
Input Voltage
Deviation (V)
Line Transient Response
7
6
5
4
C
OUT
= 10μF Electrolytic
I
OUT
= 0.1A
T
V
OUT
= 3.3V
T
A
= 25°C
C
OUT
= 10μF Electrolytic
I
OUT
= 0.1A
T
V
OUT
= 2.5V
T
A
= 25°C
≈
Output Voltage
Deviation (mV)
100
0
2 >
-100
1 >
-200
T
T
≈
Output Voltage
Deviation (mV)
≈
100
0
2 >
-100
1 >
-200
T
T
≈
Time (100μS/Div)
Time (100μs/Div)
Time (100μS/Div)
Time (100μs/Div)
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DS9161/A-31 March 2007
RT9161/A
Load Transient Response
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Load Transient Response
150
60
C
IN
= 1μF
40
C
OUT
= 10μF
20
T
A
= 25°C
2
0
>
V
IN
= 5V
V
OUT
= 3.3V
C
IN
= 1μF
100
C
OUT
= 10μF
50
T
A
= 25°C
0
2 >
-50
T
T
V
IN
= 5V
V
OUT
= 3.3V
T
T
-20
Load Current
(mA)
≈
T
Load Current
(mA)
100
50
1
-50
1>
≈
≈
T
200
100
1
10
>
≈
-100
Time (100μs/Div)
Time (100μS/Div)
Time (100μS/Div)
Time (100μs/Div)
Load Transient Response
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
60
Load Transient Response
150
C
IN
= 1μF
40
C
OUT
= 10μF
T
A
= 25°C
20
0
2 >
-20
T
T
V
IN
= 5V
V
OUT
= 2.5V
C
IN
= 1μF
100
C
OUT
= 10μF
T
A
= 25°C
50
0
2 >
-50
T
T
V
IN
= 5V
V
OUT
= 2.5V
≈
T
≈
Load Current
(mA)
≈
T
≈
100
Load Current
(mA)
50
1
1
>
200
100
1
10
>
-50
Time (100μS/Div)
Time (100μs/Div)
-100
Time (100μS/Div)
Time (100μs/Div)
0
-10
-20
-30
-40
-50
PSRR
C
IN
= 1uF
C
OUT
=
10uF
Tantalum
V
IN
= 5V
V
OUT
= 3.3V
T
A
= 25°C
0
-10
PSRR
C
IN
= 1uF
C
OUT
=
10uF
Tantalum
V
IN
= 5V
V
OUT
= 2.5V
T
A
= 25°C
100mA
100mA
PSRR (dB)
PSRR (dB)
10mA
-20
-30
-40
-50
10mA
-60
10
100
-60
10
100
1000
1K
10000
10K
100000
100K
1000000
1M
1K
1000
10K
10000
100K
100000
1M
1000000
Frequency (Hz)
DS9161/A-31 March 2007
Frequency (Hz)
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