RT9164A
1A Fixed and Adjustable Low Dropout Positive Voltage
Regulators
General Description
The RT9164A series of high performance positive voltage
regulators is designed for applications requiring low dropout
performance at fully rated current. Additionally, the RT9164A
series provides excellent regulation over variations in line
and load. Outstanding features include low dropout
performance at rated current, fast transient response,
internal current-limiting, and thermal-shutdown protection
of the output device. The RT9164A series of three terminal
regulators offers fixed and adjustable voltage options
available in space-saving SOT-223, TO-252, and TO-263
packages.
Features
Applications
Ordering Information
RT9164A-
Package Type
G : SOT-223
L: TO-252
LR : TO-252 (R-Type)
M : TO-263
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Output Voltage
Default : Adjustable
15 : 1.5V
18 : 1.8V
25 : 2.5V
28 : 2.85V
30 : 3.0V
33 : 3.3V
35 : 3.5V
Low Dropout Performance, 1.4V Max
Full Current Rating Over Line and Temperature
Fast Transient Response
±2% Output Voltage Accuracy
1.5V, 1.8V, 2.5V, 2.85V, 3.0V, 3.3V, and 3.5V Fixed
Adjustable Output Voltage
SOT-223, TO-252, and TO-263 Packages
RoHS Compliant and 100% Lead (Pb)-Free
Active SCSI Termination
Low Voltage Microcontrollers
Switching Power Supply Post-Regulator
Pin ConFigurations
(TOP VIEW)
3
VIN
2
VOUT (TAB)
1
ADJ/GND
SOT-223
3
2
VIN
VOUT (TAB)
1
ADJ/GND
TO-252
Note :
Richtek products are :
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
3
VOUT
2
ADJ/GND (TAB)
1
VIN
TO-252 (R-Type)
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
3
VIN
2
VOUT (TAB)
1
ADJ/GND
TO-263
DS9164A-15 April 2011
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1
RT9164A
Typical Application Circuit
VIN
VIN = 5V
RT9164A
VOUT
ADJ
10uF
+
+
VREF
CIN
VOUT = 3.45V
R1
133
1%
COUT
10uF
IADJ
R2
232
1%
Tantalum
R2
VOUT = VREF(1+ )+IADJ R2
R1
(1) CIN needed if device is far from filter capacitors.
(2) COUT required for stability.
Figure 1. Adjustable Voltage Regulator
RT9164A-33
VIN
VOUT
VIN = 5V
VOUT
3.3V
GND
+
+
CIN
10uF
IQ
COUT
10uF
Tantalum
(1) CIN needed if device is far from filter capacitors.
(2) COUT required for stability.
Figure 2. Fixed Voltage Regulator
RT9164A-28
VIN
VOUT
VIN = 5V
18 - 27 Lines
GND
COUT
+
+
CIN
10uF
22uF
IQ
Figure 3. Active SCSI Bus Terminator
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DS9164A-15 April 2011
RT9164A
Function Block Diagram
VIN
S.O.A.
Current
Limiting
Amplifier
LIMIT
VOUT
SENSE
Thermal Overload
Voltage
Regulation
Amplifer
VREF
ADJ/GND
Functional Pin Description
Pin Name
Pin Function
ADJ/GND
Adjust Output or Ground.
VOUT
Output Voltage.
VIN
Power Input.
DS9164A-15 April 2011
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3
RT9164A
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage -------------------------------------------------------------------------------------------------------- 15V
Power Dissipation, PD @ TA = 25°C
SOT-223 ----------------------------------------------------------------------------------------------------------------------- 0.740W
TO-252 ------------------------------------------------------------------------------------------------------------------------- 1.471W
TO-263 ------------------------------------------------------------------------------------------------------------------------- 2.222W
Package Thermal Resistance (Note 2)
SOT-223, θJA ------------------------------------------------------------------------------------------------------------------ 135°C/W
SOT-223, θJC ----------------------------------------------------------------------------------------------------------------- 19°C/W
TO-252, θJA ------------------------------------------------------------------------------------------------------------------- 68°C/W
TO-252, θJC ------------------------------------------------------------------------------------------------------------------- 7.5°C/W
TO-263, θJA ------------------------------------------------------------------------------------------------------------------- 45°C/W
TO-263, θJC ------------------------------------------------------------------------------------------------------------------- 7.8°C/W
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------------- 260°C
Junction Temperature ------------------------------------------------------------------------------------------------------- 150°C
Storage Temperature Range ---------------------------------------------------------------------------------------------- −65°C to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------------ 8kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------------- 750V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage -------------------------------------------------------------------------------------------------------- 3V to 14V
Junction Temperature Range ---------------------------------------------------------------------------------------------- −40°C to 125°C
Electrical Characteristics
(TA = 25°C, unless otherwise specified)
Parameter
Reference Voltage
(Note 5)
RT9164A
Symbol
VREF
RT9164A -15
RT9164A -18
Output Voltage
(Note 5)
RT9164A -25 VOUT
RT9164A -28
RT9164A -30
Test Conditions
Min
Typ
Max
Unit
IOUT = 10mA, (VIN VOUT) = 2V,
TA = 25C
1.243 1.256 1.281
V
10mA IOUT 1.0A,
1.5V VIN VOUT 10V
1.231 1.256 1.294
V
IOUT = 10mA, VIN = 3.3V, TJ = 25C
1.485
1.5
1.53
10mA IOUT 1.0A, 3.3V VIN 10V 1.470
1.5
1.55
IOUT = 10mA, VIN = 3.3V, TJ = 25C
1.797 1.815
1.85
10mA IOUT 1.0A, 3.3V VIN 10V 1.779 1.815
1.87
IOUT = 10mA, VIN = 4.0V, TJ = 25C
2.475 2.500 2.550
10mA IOUT 1.0A, 4.0V VIN 10V 2.450 2.500 2.575
IOUT= 10mA, VIN= 4.25V, TJ = 25C
V
2.822 2.850 2.910
10mA IOUT 1.0A, 4.25V VIN 10V 2.793 2.850 2.936
IOUT = 10mA, VIN= 4.5V, TJ = 25C
2.970 3.000 3.060
10mA IOUT 1.0A, 4.5V VIN 10V
2.940 3.000 3.090
To be continued
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DS9164A-15 April 2011
RT9164A
Parameter
Symbol
IOUT = 10mA, VIN = 4.75V, T J = 25C
RT9164A -33
Output Voltage
V OUT
(Note 5)
RT9164A -35
Line Regulation
(Note 5)
Dropout Voltage
Min
Typ
Max
10mA IOUT 1.0A, 4.75V V IN 10V 3.234 3.300 3.400
IOUT = 10mA, VIN= 5V, TJ = 25C
3.465 3.500 3.570
--
0.1
0.3
RT9164A -15
IOUT = 10mA, 3.3V VIN 15V
--
1
6
RT9164A -18
IOUT = 10mA, 3.3V VIN 15V
--
1
6
IOUT = 10mA, 4.0V VIN 15V
--
1
6
RT9164A -28
IOUT = 10mA, 4.25V VIN 15V
--
1
6
RT9164A -30
IOUT = 10mA, 4.5V VIN 15V
--
1
6
RT9164A -33
IOUT = 10mA, 4.75V VIN 15V
--
1
6
RT9164A -35
IOUT = 10mA, 5.0V VIN 15V
--
1
6
RT9164A
(V IN VOUT) = 3V, 10mA I OUT 1.0A
--
0.2
0.4
RT9164A -15
VIN = 3.3V, 10mA I OUT 1.0A
--
1
10
RT9164A -18
VIN = 3.3V, 10mA I OUT 1.0A
--
1
10
VIN = 4.0V, 10mA I OUT 1.0A
--
1
10
VIN = 4.25V, 10mA I OUT 1.0A
--
1
10
RT9164A -30
VIN = 4.5V, 10mA I OUT 1.0A
--
1
12
RT9164A -33
VIN = 4.75V, 10mA I OUT 1.0A
--
1
12
RT9164A -35
VIN = 5.0V, 10mA I OUT 1.0A
IOUT = 500mA
IOUT = 1.0A
----
1
1.15
1.3
15
1.25
1.4
1.0
1.8
--
RT9164A -28
(Note 6)
Current Limit
V
10mA IOUT 1.0A, 5.0V V IN 10V 3.430 3.500 3.605
IOUT = 10mA,
1.5V VIN V OUT 10V
RT9164A -25
Unit
3.267 3.300 3.365
RT9164A
RT9164A -25
Load Regulation
(Note 5)
Test Conditions
VLINE
VLOAD
V DROP
ILIM
VIN = 5V
%
mV
%
mV
V
A
Minimum Load Current RT9164A
(V IN V OUT) = 2V
--
5
10
Quiescent Current
VIN = 5V
--
5
10
fRIPPLE = 120Hz ,
(V IN V OUT) = 2V, VRIPPLE = 1V P-P
--
72
--
dB
--
65
120
A
--
0.2
5
A
RT9164A -XX IQ
Ripple Rejection
PSRR
Adjust Pin Current
IADJ
Adjust Pin Current Change
IADJ
DS9164A-15 April 2011
10mA IOUT 1.0A, V IN = 5V
mA
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5
RT9164A
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 T A = 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard. The case point of θJC is on the center of the exposed pad. The pad size
is 6mm2 on SOT-223 packages, 100mm2 on TO-252 packages, 125mm2 on TO-263 packages.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Low duty cycle pulse testing with Kelvin connections.
Note 6. The dropout voltage is defined as VIN − VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
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DS9164A-15 April 2011
RT9164A
Typical Operating Characteristics
Output Voltage vs. Temperature
Reference Voltage vs. Temperature
1.27
3.4
Reference Voltage (V)
VOUT = 3.3V
Output Voltage (V)
3
2.6
VOUT = 2.5V
2.2
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL =
1.8
VOUT = 1.5V
1.4
1.26
1.25
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
R1 = R2 = 100Ω
RL =
1.24
1.23
-50
-25
0
25
50
75
100
125
-50
Temperature (° C)
0
50
75
100
125
Quiescent Current vs. Temperature
ADJ Pin Current vs. Temperature
7
60
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
R1 = R2 = 100Ω
RL =
50
Quiescent Current (mA)
70
6
5
VOUT = 2.5V
4
3
2
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL =
1
0
40
-50
-25
0
25
50
75
100
-50
125
-25
0
Temperature (° C)
Current Limit vs. Input Voltage
25
50
75
Temperature(° C)
100
125
Current Limit vs. Temperature
2
3
2.5
1.9
VOUT = 2.5V, RL = 1Ω
2
1.5
1
Current Limit (A)1
Current Limit (A)
25
Temperature (° C)
80
ADJ Pin Current (uA)
-25
1.8
VOUT = 2.5V, RL = 1Ω
1.7
VIN = 5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
1.6
0.5
CIN = 10uF Electrolytic
CO = 10uF Tantalum
0
2
4
6
8
10
Input Voltage (V)
DS9164A-15 April 2011
12
14
1.5
-50
-25
0
25
50
75
100
125
Temperature (° C)
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RT9164A
Current Limit
Dropout Voltage vs. Io
3.5
VOUT = 2.5V
-40°C
3
1.2
25°C
1.1
1.0
125°C
0.9
Current Limit (A)
Dropout Voltage (V)1
1.3
0
0.3
0.6
0.9
1.2
2
1.5
1
0
1.5
Time (2.5ms/Div)
Load Current (A)
20
10
VOUT = 1.5V
CO = 10uF Tantalum
ILOAD = 100mA
0
Line Transient Response
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Line Transient Response
30
Input Voltage
Deviation (V)
6
5
20
0
7
6
5
Line Transient Response
Load Transient Response
VOUT = 3.3V
CO = 10uF Tantalum
ILOAD = 100mA
0
300
200
VIN = 3.3V, VOUT = 1.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
100
0
-100
Load Current (A)
-20
Input Voltage
Deviation (V)
30
Time (10us/Div)
20
7
6
5
Time (10us/Div)
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VOUT = 2.5V
CO = 10uF Tantalum
ILOAD = 100mA
Time (10us/Div)
Output Voltage
Deviation (mV)
Input Voltage
Deviation (V)
Output Voltage
Deviation (mV)
7
30
40
-20
-10
40
VIN = 5V, VOUT = 2.5V
CIN = 10uF Electrolytic
CO = 10uF Tantalum
RL = 1Ω
0.5
CIN = 10uF Electrolytic
CO = 10uF Tantalum
0.8
2.5
1
0.5
0
Time (10us/Div)
DS9164A-15 April 2011
RT9164A
300
200
100
VIN = 3.3V, VOUT = 1.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
Load Transient Response
300
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Load Transient Response
Load Current (A)
2
1
0
300
200
100
0
1
0.5
0
Time (10us/Div)
Time (10us/Div)
Load Transient Response
Load Transient Response
VIN = 5V, VOUT = 2.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
300
Load Current (A)
-100
Load Current (A)
100
VIN = 5V, VOUT = 2.5V
CIN = CO = 10uF Tantalum
Preload = 0.1A
-100
Output Voltage
Deviation (mV)
Output Voltage
Deviation (mV)
Load Current (A)
-100
200
2
1
0
Time (10us/Div)
VVININ == 5V,
5V, VVOUT
3.3V
OUT == 3.3V
200 CCININ==CCOO==10uF
10uFTantalum
Tantalum
Preload
Preload==0.1A
0.1A
100
0
-100
1
0.5
0
Time (10us/Div)
Output Voltage
Deviation (mV)
Load Transient Response
300
200
100
VIN = 5V, VOUT = 3.3V
CIN = CO = 10uF Tantalum
Preload = 0.1A
0
Load Current (A)
-100
2
1
0
Time (10us/Div)
DS9164A-15 April 2011
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RT9164A
Application Information
Output voltage adjustment
Output Capacitor
Like most regulators, the RT9164A regulates the output
by comparing the output voltage to an internally generated
reference voltage. On the adjustable version as shown in
Figure 4, the VREF is available externally as 1.25V between
VOUT and ADJ. The voltage ratio formed by R1 and R2
should be set to conduct 10mA (minimum output load).
The output voltage is given by the following equation :
RT9164A requires a capacitor from VOUT to GND to provide
compensation feedback to the internal gain stage. This is
to ensure stability at the output terminal. Typically, 10μF
tantalum or 50μF aluminum electrolytic with 30mΩ to 2Ω
range capacitor is sufficient.
VOUT = VREF (1 +
R2
R1
) + IADJ R2
On fixed versions of RT9164A, the voltage divider is provided
internally.
The output capacitor does not have a theoretical upper
limit and increasing its value will increase stability.
COUT = 100μF or more is typical for high current regulator
design.
Region of Stable COUT ESR vs. Load Current
10
COUT = 100uF
RT9164A
VIN
VOUT
VIN
VOUT
10uF
R1
COUT
10uF
IADJ
+
65uF
+
+
VREF
CADJ
R2
C OUT ESR (Ω)
ADJ
CIN
COUT = 10uF
1
Stable
0.1
Figure 4. Basic Adjustable Regulator
Input Bypass Capacitor
Instable
Instable
0.01
0
0.2
An input capacitor is recommended. A 10μF tantalum on
the input is a suitable input bypassing for almost all
applications.
0.4
0.6
0.8
1
Load Current (A)
Figure 5
Adjust Terminal Bypass Capacitor
Load Regulation
The adjust terminal can be bypassed to ground with a
bypass capacitor (CADJ) to improve ripple rejection. This
bypass capacitor prevents ripple from being amplified as
the output voltage is increased. At any ripple frequency,
the impedance of the CADJ should be less than R1 to prevent
the ripple from being amplified :
When the adjustable regulator is used (Figure 6), the best
load regulation is accomplished when the top of the resistor
divider (R1) is connected directly to the output pin of the
RT9164A. When so connected, RP is not multiplied by
(2π x fRIPPLE x CADJ) < R1
the divider ratio. For Fixed output version, the top of R1 is
internally connected to the output and ground pins can be
connected to low side of the load.
The R1 is the resistor between the output and the adjust
pin. Its value is normally in the range of 100-200Ω. For
example, with R1 = 124Ω and fRIPPLE = 120Hz, the CADJ
should be > 11μF.
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DS9164A-15 April 2011
RT9164A
VIN
RT9164A
VIN
VOUT
ADJ
RP Parasitic
Line Resistance
R1
(Connect R1 to VOUT
or case)
RL
R2
Connect R2 to load
Figure 6. Best Load Regulation Using Adjustable
Output Regulator
Thermal Protection
RT9164A has thermal protection which limits junction
temperature to 150°C. However, device functionality is only
guaranteed to a maximum junction temperature of 125°C.
The power dissipation and junction temperature for RT9164A
are given by
PD = (VIN − VOUT) x IOUT
TJUNCTION = TAMBIENT + (PD x θJA)
Note: TJUNCTION must not exceed 125° C
Current Limit Protection
RT9164A is protected against overload conditions. Current
protection is triggered at typically 1.8A.
Thermal Consideration
The RT9164A series contain thermal limiting circuitry
designed to protect itself from over-temperature conditions.
Even for normal load conditions, maximum junction
temperature ratings must not be exceeded. As mention in
thermal protection section, we need to consider all sources
of thermal resistance between junction and ambient. It
includes junction-to-case, case-to-heat-sink interface, and
heat sink thermal resistance itself.
Junction-to-case thermal resistance is specified from the
IC junction to the bottom of the case directly below the
die. Proper mounting is required to ensure the best possible
thermal flow from this area of the package to the heat
sink. The case of all devices in this series is electrically
connected to the output. Therefore, if the case of the device
must be electrically isolated, a thermally conductive spacer
is recommended.
DS9164A-15 April 2011
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11
RT9164A
Outline Dimension
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
1.400
1.800
0.055
0.071
A1
0.020
0.100
0.001
0.004
b
0.600
0.840
0.024
0.033
B
3.300
3.700
0.130
0.146
C
6.700
7.300
0.264
0.287
D
6.300
6.700
0.248
0.264
b1
2.900
3.100
0.114
0.122
e
2.300
0.091
H
0.230
0.350
0.009
0.014
L
1.500
2.000
0.059
0.079
L1
0.800
1.100
0.031
0.043
3-Lead SOT-223 Surface Mount Package
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DS9164A-15 April 2011
RT9164A
D
U
C
D1
R
B
T
V
E
S
L1
L3
b1
b
L2
e
b2
A
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
2.184
2.388
0.086
0.094
B
0.889
2.032
0.035
0.080
b
0.508
0.889
0.020
0.035
b1
1.016 Ref.
0.040 Ref.
b2
0.457
0.584
0.018
0.023
C
0.457
0.584
0.018
0.023
D
6.350
6.731
0.250
0.265
D1
5.207
5.461
0.205
0.215
E
5.334
6.223
0.210
0.245
e
2.108
2.438
0.083
0.096
L1
9.398
10.414
0.370
0.410
L2
L3
0.508 Ref.
0.635
1.016
0.020 Ref.
0.025
0.040
U
3.810 Ref.
0.150 Ref.
V
3.048 Ref.
0.120 Ref.
R
0.200
0.850
0.008
0.033
S
2.500
3.400
0.098
0.134
T
0.500
0.850
0.020
0.033
3-Lead TO-252 Surface Mount Package
DS9164A-15 April 2011
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13
RT9164A
C
D
U
B
V
E
L1
b1
L2
e
b2
b
A
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 Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
5F, No. 95, Minchiuan Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
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.
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DS9164A-15 April 2011