DS9072AB 01

RT9072A/B
80V, Low Dropout Voltage Linear Regulator
General Description
Features
The RT9072A/B is a high voltage (80V operation), low
quiescent current, low dropout linear regulator. The
device supplies 20mA output current with a maximum
dropout voltage of 230mV. Its low quiescent and
shutdown currents (23A operating and 3A shutdown)
are ideal for use in battery-powered and/or high voltage
systems. Ground current is well-controlled in all
conditions, including dropout.







The RT9072A/B operates with any reasonable output
capacitors including 1F low-ESR ceramic types. It
features excellent line and load transient responses.
Internal protection circuitry includes reverse-battery
protection, current limiting, thermal shutdown, and
reverse current protection. Output voltage accuracy is
±3% over the entire line, load, and temperature range.





The RT9072A/B has an adjustable output voltage
(1.25V to 60V). It is available in the SOT-23-5 package.



2% Initial Output Tolerance
3%Output
Tolerance
over
Line,
Load,
Temperature Range
Stable with 1F Output Capacitor
Stable with Aluminum, Tantalum or Ceramic
Capacitors
No Reverse-Current Protection Diode Needed
80V Reverse-Battery Protection
Internal Current Limit
Internal Thermal Shutdown Protection
Marking Information
RT9072AGB
Applications

Wide Input Voltage Range: 4.5V to 80V
Low Quiescent Current : 23A Operating and 3A
Shutdown
Low Dropout Voltage: 180mV (typical) at 20mA
Adjustable (1.25V to 60V) Output Voltage
4Y=DNN
Low Current, High Voltage Regulators
Battery Powered Applications
Telecom and Datacom Applications
Automotive Applications
4Y= : Product Code
DNN : Date Code
RT9072BGB
4X=DNN
4X= : Product Code
DNN : Date Code
Simplified Application Circuit
RT9072A/B
VIN
VIN
VOUT
VOUT
R1
CIN
CCOMP
COUT
FB
SHDN/
SHDN
R2
GND
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DS9072A/B-01
June 2016
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RT9072A/B
Ordering Information
Pin Configurations
(TOP VIEW)
RT9072A/B
Package Type
B : SOT-23-5
VOUT
Lead Plating System
G : Green (Halogen Free and Pb Free)
A : Low Shutdown
B : High Shutdown
FB
5
4
2
3
VIN GND SHDN/
SHDN
Note :
SOT-23-5
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.
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Power Input. Bypass VIN with a 0.18F or larger capacitor with
adequate voltage rating.
2
GND
Ground.
3
Shutdown Control Input. Connect SHDN of RT9072B high to disable
the output voltage and reduce the IC’s quiescent current to 3A
SHDN
(typical). Connect SHDN low to enable the output. SHDN is a
(RT9072B)
high-voltage pin and can be connected directly to a high-voltage input
less than 60V.
Shutdown Control Input. Connect ̅̅̅̅̅̅̅̅̅
SHDN of RT9072A low to disable
the
output
voltage
and
reduce
the
IC’s quiescent current to 3A
̅̅̅̅̅̅̅̅̅
SHDN
(typical). Connect ̅̅̅̅̅̅̅̅̅
SHDN high to enable the output. ̅̅̅̅̅̅̅̅̅
SHDN is a
(RT9072A)
high-voltage pin and can be connected directly to a high-voltage input
less than 60V.
4
FB
Feedback Voltage Input. Connect to the center tap of a resistor divider
for setting the output voltage.
5
VOUT
Output Voltage Pin. The VOUT pin supplies power to the load. A
minimum output capacitor of 1F is required for stable operation.
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DS9072A/B-01
June 2016
RT9072A/B
Function Block Diagram
VIN
VOUT
Current
Limit
SHDN/
SHDN
- +
OverTemperature
Protection
FB
VREF
GND
Operation
The RT9072A/B is a high input-voltage linear regulator
specifically designed to minimize external components.
The input voltage range is from 4.5V to 80V. The
Over-Temperature Protection
device supplies 20mA of output current with a
maximum dropout voltage of 230mV. Its 23A
temperature exceeds 150°C (typ.). Once the junction
temperature cools down by approximately 20°C, the
quiescent and 3A shutdown currents make it ideal for
use in battery-powered applications. Unlike many PNP
regulator will automatically resume operation.
LDO regulators, ground current does not increase
much in dropout conditions.
Output Transistor
The RT9072A/B includes a built-in PNP output
transistor configured for low dropout voltage. The
output transistor blocks reverse current from output to
input node if the output voltage is held higher than the
input voltage (such as in battery-backup applications).
Error Amplifier
The over-temperature protection function will turn off
the PNP output transistor when the internal junction
Reverse-Battery Protection
The RT9072A/B VIN can withstand reverse voltages as
high as 80V. Both the IC and the load are protected
and no negative voltage will appear at the output.
Reverse-Output Protection
The RT9072A/B protects against current flow to the
input (VIN) when the output voltage exceeds VIN.
If the input is left open circuit or grounded, the FB pin
will act like a resistor (typically 10k) in series with a
The Error Amplifier compares the output feedback
diode when pulled above ground. If the FB pin is
connected to a resistor divider now and the output
voltage at FB to an internal reference voltage and
controls the PNP output transistor's base current to
maintain output voltage regulation.
voltage is held higher than the input voltage, a current
will conduct from output via the resistor divider and FB
Current Limit Protection
The RT9072A/B provides a current limit function to
prevent damage during output over-load or
shorted-circuit conditions. The output current is
detected by an internal current-sense transistor.
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DS9072A/B-01
June 2016
node to ground. Because the current is limited by the
resistor divider and FB internal resistor, no additional
output blocking diode is needed if the limited current is
acceptable.
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RT9072A/B
Shutdown Control
The RT9072B SHDN input is an active-high input that
turns off the output transistor and reduces the
quiescent current to 3A typical. Connect SHDN to a
voltage below 0.4V for normal operation.
The RT9072A ̅̅̅̅̅̅̅̅̅
SHDN input is an active-low input that
turns off the output transistor and reduces the
̅̅̅̅̅̅̅̅̅ to a
quiescent current to 3A typical. Connect SHDN
voltage above 2V for normal operation.
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DS9072A/B-01
June 2016
RT9072A/B
Absolute Maximum Ratings
(Note 1)

VIN Pin Voltage -------------------------------------------------------------------------------------------------------- 80V to 90V

̅̅̅̅̅̅̅̅̅ Pin Voltage ------------------------------------------------------------------------------------------ 0.3V to 60V
SHDN/SHDN

VOUT to GND Voltage ----------------------------------------------------------------------------------------------- 80V to 80V

VOUT to VIN Voltage------------------------------------------------------------------------------------------------- 80V to 80V

FB Pin Voltage --------------------------------------------------------------------------------------------------------- 0.3V to 7V

Power Dissipation, PD @ TA = 25C
SOT-23-5 ---------------------------------------------------------------------------------------------------------------- 0.45W

Package Thermal Resistance
(Note 2)
SOT-23-5, JA ---------------------------------------------------------------------------------------------------------- 218.1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 Model) ----------------------------------------------------------------------------------------- 2kV
MM (Machine Model) ------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 4)

Supply Input Voltage ------------------------------------------------------------------------------------------------- 4.5V to 80V

Ambient Temperature Range--------------------------------------------------------------------------------------- 40C to 85C

Junction Temperature Range -------------------------------------------------------------------------------------- 40C to 125C
Electrical Characteristics
(4.5V < VIN < 80V, VSHDN
̅̅̅̅̅̅̅̅̅ = 2V (RT9072A), VSHDN = 0V (RT9072B), FB pin connected to VOUT pin, COUT = 1F (ceramic), TA =
25C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
ILOAD = 20mA
4.5
--
80
V
VIN = 12V, ILOAD = 100A
1.23
1.25
1.27
100A < ILOAD < 20mA
1.21
1.25
1.29
Input Voltage
VIN
FB Pin Voltage
VFB
Line Regulation
VLINE
VIN = 4.5V to 80V, ILOAD = 100A
--
1
10
mV
Load Regulation
VLOAD
VIN = 12V, ILOAD = 100A to 20mA
--
3
25
mV
ILOAD = 100A
--
9
50
ILOAD = 1mA
--
37
100
ILOAD = 10mA
--
130
200
ILOAD = 20mA
--
180
230
ILOAD = 0mA
--
20
30
ILOAD = 20mA
--
750
1200
COUT = 1F, ILOAD = 20mA, BW =
10Hz to 100kHz
--
120
--
VRMS
--
8
100
nA
Dropout Voltage
VDROP
GND Pin Current
IGND
Output Voltage Noise
VON
FB Pin Bias Current
IFB
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DS9072A/B-01
June 2016
V
mV
A
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RT9072A/B
Parameter
Symbol
Test Conditions
Min
Typ
Max
--
2
Unit
VIH
RT9072A Off to On; RT9072B On to
Off
--
VIL
RT9072A On to Off; RT9072B Off to
On
0.4
--
--
ISHDN
VSHDN/V̅̅̅̅̅̅̅̅̅̅̅
SHDN = 0V
--
0
0.1
I̅̅̅̅̅̅̅̅̅̅̅
SHDN
VSHDN/V̅̅̅̅̅̅̅̅̅̅̅
SHDN = 2V
--
0.4
2
Quiescent Current in
Shutdown
ISD
VIN = 6V, V̅̅̅̅̅̅̅̅̅̅̅
SHDN = 2V or VSHDN =
0V
--
3
10
A
Power Supply Rejection
Rate
PSRR
VIN = 7V (Avg), VRIPPLE = 0.5 VP-P,
f RIPPLE = 120Hz, ILOAD = 20mA
--
75
--
dB
Output Current Limit
Input Reverse Leakage
Current
ILIM
VIN = 12V, VOUT = 11V, VFB = 1.2V
25
40
--
mA
IVINr
VIN = –80V, VOUT = 0V
--
--
6
mA
Reverse Output Current
IVOUTr
FB connect to OUT, VOUT = 1.27V,
VIN < 0V
--
19
40
A
Over-Temperature
Protection
TSD
--
150
--
C
Shutdown Threshold
̅̅̅̅̅̅̅̅̅ Pin Current
SHDN/SHDN
V
A
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. JA is measured at TA = 25C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. JC is
measured at the exposed pad of the package.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
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DS9072A/B-01
June 2016
RT9072A/B
Typical Application Circuit
VIN
4.5V to 80V
RT9072A/B
VIN
VOUT
CIN
0.18μF
R1
VOUT
COUT 1.25V to 60V
1μF
CCOMP
FB
SHDN/
SHDN
R2
GND
Figure 1. RT9072A/B Adjustable Output
VIN
4.5V to 80V
RT9072A/B
VIN
VOUT
MJD31C
CIN
0.18μF
R3
100
SHDN/
SHDN
GND
R1
CCOMP
COUT
10μF
VOUT
1.25V to 60V
FB
R2
Figure 2. RT9072A/B External Transistor Application
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June 2016
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RT9072A/B
Typical Operating Characteristics
Quiescent Current vs. Supply Voltage
Output Voltage vs. Load Current
30
0.4
0.32
25
0.16
Quiescent Current (μA)
Output Voltage (%)
0.24
VIN = 12V
VOUT = 3.3V
0.08
0
-0.08
-0.16
-0.24
20
15
10
5
-0.32
-0.4
0
2.5
5
7.5
10
12.5
15
17.5
0
20
0
10
20
30
Load Current (mA)
40
50
60
70
80
Supply Voltage (V)
Output Voltage vs. Temperature
Quiescent Current vs. Temperature
0.5
40
0.4
35
Quiescent Current (µA)
Output Voltage (%)
0.3
0.2
0.1
0
-0.1
-0.2
VIN = 4.5V
VIN = 80V
IOUT = 0.1mA
-0.3
-0.4
30
25
20
15
10
VIN = 12V
5
0
-0.5
-50
-25
0
25
50
75
100
125
-50
150
-25
0
Temperature (℃)
PSRR vs. Frequency
50
75
100
125
150
Shutdown Current vs. Supply Voltage
0
10
-10
9
COUT = 0.47μF
COUT = 4.7μF
8
Shutdown Current (μA)
-20
-30
PSRR (dB)
25
Temperature (°C)
-40
-50
-60
-70
7
6
5
4
3
-80
2
-90
1
-100
10
100
1000
10000
100000
Frequency (Hz)
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1000000
0
0
10
20
30
40
50
60
70
80
Supply Voltage (V)
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DS9072A/B-01
June 2016
RT9072A/B
Output Voltage vs. Supply Voltage
Current Limit vs. Supply Voltage
0.1
80
70
0
Output Voltage (%)
Current Limit (mA)
60
50
40
30
-0.1
-0.2
IOUT
IOUT
IOUT
IOUT
-0.3
20
-0.4
10
0
0
10
20
30
40
50
60
70
80
-0.5
0
10
20
Supply Voltage (V)
30
40
50
60
70
80
Supply Voltage (V)
Reverse Current vs. Temperature
Ground Current vs. Supply Voltage
12
1000
IOUT = 0mA
900
10
IOUT = 0.1mA
800
Reverse Current (μA)
Ground Current (μA)
= 0mA
= 0.1mA
= 1mA
= 20mA
IOUT = 1mA
700
IOUT = 10mA
600
IOUT = 20mA
500
400
300
8
6
4
2
200
VIN = -80V
100
0
0
-50
0
10
20
30
40
50
60
70
-25
0
25
50
75
100
125
150
Temperature (℃)
80
Supply Voltage (V)
Dropout Voltage vs. Temperature
300
VOUT vs. VIN
IOUT
IOUT
IOUT
IOUT
Dropout Voltage (mV)
250
200
= 0.1mA
= 1mA
= 10mA
= 20mA
+80V
IOUT = 20mA
COUT = 1μF
150
VIN (30V/Div)
100
VOUT (2V/Div)
50
-80V
0
-50
-25
0
25
50
75
100
125
Temperature (℃)
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June 2016
150
Time (1msec/Div)
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RT9072A/B
Line Transient Waveform Falling
Line Transient Waveform Rising
IOUT = 20mA
COUT = 1μF
CCOMP = 220pF
VOUT (10V/Div)
VOUT (10V/Div)
VOUT_AC
(100mV/Div)
VOUT_AC
(100mV/Div)
IOUT = 20mA
COUT = 1μF
CCOMP = 220pF
Time (25μsec/Div)
Time (25μsec/Div)
Load Transient Waveform
Line Transient Waveform Full
VOUT (10V/Div)
VOUT_AC
(100mV/Div)
IOUT
(10mA/Div)
IOUT = 20mA
COUT = 1μF
CCOMP = 220pF
VOUT_AC
(20mV/Div)
VIN = 12V
VOUT = 3.3V
Time (50μsec/Div)
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IOUT = 20mA
COUT = 10μF
CCOMP = 220pF
Time (50μsec/Div)
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DS9072A/B-01
June 2016
RT9072A/B
Application Information
The RT9072A/B is a high input-voltage linear regulator
specifically designed to minimize external components.
The input voltage range is from 4.5V to 80V. The
device supplies 20mA of output current with a
maximum dropout voltage of 230mV.
Adjustable Output Voltage and Compensation
The adjustable output may be set to provide from 1.25V
to 80V, using external feedback voltage divider
resistors (Figure 1). To achieve the correct
compensation (with your external FB divider, use a
lower divider resistor (R2) value below 100k.
Calculate R1 according to the following formula : R2 =
R1 / (VOUT / 1.25V – 1). Then, calculate the
compensation capacitor (CCOMP) value according to
the following formula : CCOMP = 25s/R1
Thermal Considerations
The RT9072A/B’s high input-voltage capability and
high output current capability require careful use to
avoid over-heating the IC and activating the internal
thermal protection. To avoid thermal shutdown, do not
exceed the IC’s maximum operating junction
temperature range of 125C.
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature.
The maximum power dissipation can be calculated by
the following formula :
PD(MAX) = (TJ(MAX)  TA) / JA
Added External NPN for High-Current Applications
where TJ(MAX) is the maximum junction temperature,
TA is the ambient temperature, and JA is the junction to
Higher
ambient thermal resistance.
output
currents and/or
increased
power
dissipation are possible using an external NPN output
transistor. VOUT drives the base of the transistor and
FB monitors the actual output voltage, as in normal
applications. The output (Figure 2) can be used.
Component Selection
A low-ESR capacitor such as ceramic type must be
connected between VIN and GND with short, wide
traces to bypass input noise. RT9072A/B is designed to
work with small input capacitor to reduce the cost from
high-voltage low-ESR requirement. To guarantee a
minimum 0.1F input capacitance, a ceramic 0.18F
input capacitor with an appropriate voltage rating is
recommended.
The RT9072A/B operates with any reasonable output
capacitor including low-ESR ceramic types. Low-ESR
aluminum and tantalum capacitor may also be used. A
minimum of 1F is recommended and much higher
values are also acceptable. Connect the output
capacitor between VOUT and GND with short, wide
traces to keep the circuit stable.
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DS9072A/B-01
June 2016
For recommended operating condition specifications,
the maximum junction temperature is 125C. The
junction to ambient thermal resistance, JA, is layout
dependent. For SOT-23-5 package, the thermal
resistance, JA, is 218.1C/W on a standard JEDEC
51-7 four-layer thermal test board. The maximum
power dissipation at TA = 25C can be calculated by
the following formula :
PD(MAX) = (125C  25C) / (218.1C/W) = 0.45W for
SOT-23-5 package
The maximum power dissipation depends on the
operating ambient temperature for fixed TJ(MAX) and
thermal resistance, JA. The derating curve in Figure 3
allows the designer to see the effect of rising ambient
temperature on the maximum power dissipation.
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RT9072A/B
CCOMP
2
R1
5
0.3
VOUT
3
FB
COUT
4
R2
0.4
VIN GND SHDN/
SHDN
GND
Four-Layer PCB
VOUT
Maximum Power Dissipation (W)1
0.5
GND
CIN
0.2
0.1
Figure 4. PCB Layout Guide
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 3. Derating Curve of Maximum Power
Dissipation
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DS9072A/B-01
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RT9072A/B
Outline Dimension
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.889
1.295
0.035
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.356
0.559
0.014
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.080
0.254
0.003
0.010
L
0.300
0.610
0.012
0.024
SOT-23-5 Surface Mount Package
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.
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
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June 2016
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