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)
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
Lead Plating System
P : Pb Free
directly or through a Richtek distributor located in your
G : Green (Halogen Free and Pb Free)
area.
Output Voltage
15 : 1.5V
Pin Configurations
16 : 1.6V
:
(TOP VIEW)
49 : 4.9V
50 : 5.0V
VIN
500mA Output Current
300mA Output Current
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.
GND
3
1
2
2
3
VOUT
SOT-23-3
GND
VIN VOUT
(TAB)
SOT-89
1
2
3
GND
VIN VOUT
(TAB)
SOT-223
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RT9161/A
3
2
1
VOUT
GND
VIN
3
2
1
VOUT
VIN
GND
TO-92 (L-Type)
TO-92 (T-Type)
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-35 April 2011
RT9161/A
Absolute Maximum Ratings
Input Voltage ----------------------------------------------------------------------------------------------------------------
−0.3
to 14V
Operating Junction Temperature Range -------------------------------------------------------------------------------
−40°C
to 125°C
Storage Temperature Range ---------------------------------------------------------------------------------------------
−65°C
to 150°C
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-3 --------------------------------------------------------------------------------------------------------------------- 0.4W
SOT-89 ----------------------------------------------------------------------------------------------------------------------- 0.571W
SOT-223 --------------------------------------------------------------------------------------------------------------------- 0.741W
TO-92 ------------------------------------------------------------------------------------------------------------------------- 0.625W
Package Thermal Resistance (Note 1)
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
Current Limit
(Note 3)
Dropout Voltage
Standby Current
(Note 2)
RT9161
RT9161A
(Note 4)
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
Unit
%
PPM/°C
%V
OUT
mV
mA
mV
μA
ΔV
LINE
ΔV
LOAD
I
LIM
V
DROP
I
L
= 1mA, V
IN
= 4.5 to 12V
I
L
= 1mA to 300/500mA, V
IN
= 5V
V
IN
= 5V, V
OUT
= 0V
I
L
= 300/500mA
--
--
350
500
--
--
450/750 600/1000
I
STANDBY
I
L
= 0, V
IN
= 12V
Note 1.
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.
Note 2.
Regulation is measured at constant junction temperature, using pulsed ON time.
Note 3.
Current Limit is measured at constant junction temperature, using pulsed ON time.
Note 4.
The dropout voltage is defined as V
IN
−
V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
−
100mV.
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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
Line Transient Response
7
Input Voltage
Deviation (V)
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
≈
T
T
≈
0
2 >
-100
1 >
-200
Time (100μS/Div)
Time (100μs/Div)
Time (100μS/Div)
Time (100μs/Div)
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DS9161/A-35 April 2011
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
100
Load Current
(mA)
50
1
1
>
≈
Load Current
(mA)
≈
T
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-35 April 2011
Frequency (Hz)
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