2024年9月24日发(作者：张志新)
®
RT9020
500mA, Low Dropout, Low Noise Ultra-Fast With Soft Start
CMOS LDO Regulator
General Description
The RT9020 is a high-performance, 500mA LDO regulator,
offering extremely high PSRR and ultra-low dropout, ideal
for portable RF and wireless applications with demanding
performance and space requirements.
The RT9020 quiescent current is as low as 25μA, further
prolonging the battery life. The RT9020 also works with
low-ESR ceramic capacitors, reducing the amount of board
space necessary for power applications, critical in hand-
held wireless devices.
The RT9020 consumes typical 0.7μA in shutdown mode
and has fast turn-on time less than 70μs (without C
SS
).
The other features include ultra-low dropout voltage, high
output accuracy, current limiting protection, and high ripple
rejection ratio. Tiny packages SOT-23-5 and SC-70-5 are
available.
Features
Wide Operating Voltage Ranges : 2.2V to 5.5V
Low Dropout : 250mV at 500mA
5mA Discharge Current of V
OUT
when IC Shutdown
Ultra-Low-Noise for DSC Application
Ultra-Fast Response in Line/Load Transient
Current Limiting Protection
Thermal Shutdown Protection
High Power Supply Rejection Ratio
Output Only 1
μ
F Capacitor Required for Stability
TTL-Logic-Controlled Shutdown Input
RoHS Compliant and 100% Lead (Pb)-Free
Moisture Sensitivity Level : Level 3
Applications
Digital Still Camera
CDMA/GSM Cellular Handsets
Portable Information Appliances
Laptop, Palmtops, Notebook Computers
Mini PCI & PCI-Express Cards
PCMCIA & New Cards
Ordering Information
RT9020
-
Package Type
B : SOT-23-5
U5 : SC-70-5
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Fixed Output Voltage
12 : 1.2V
15 : 1.5V
16 : 1.6V
:
32 : 3.2V
33 : 3.3V
1B : 1.25V
1H : 1.85V
2H : 2.85V
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Pin Configuration
TOP VIEW
VOUT
5
2
SS
4
3
VIN
GNDEN
SOT-23-5 / SC-70-5
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
1
RT9020
Typical Application Circuit
V
IN
VIN
C
IN
1uF/
X7R
VOUT
RT9020
C
OUT
1uF/
X7R
V
OUT
Chip Enable
EN
GND
SS
C
SS
0.5nF
Functional Pin Description
Pin Number Pin Name Pin Function
1 VIN Supply input.
2 GND Common ground.
Enable input logic, active high. When the EN goes to a logic low, the device will
3 EN
be shutdown.
4 SS Soft start.
5 VOUT Regulator output.
Functional Block Diagram
SS
EN
1µA
POR
OTP
V
REF
Current
Limit
VIN
-
+
MOS
Driver
VOUT
GND
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
2
DS9020-07 July 2017
RT9020
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage------------------------------------------------------------------------------------------------------
EN Input Voltage-----------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-5--------------------------------------------------------------------------------------------------------------------
SC-70-5----------------------------------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
SOT-23-5, θ
JA
---------------------------------------------------------------------------------------------------------------
SC-70-5, θ
JA
----------------------------------------------------------------------------------------------------------------
Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------------
Junction Temperature-----------------------------------------------------------------------------------------------------
Storage Temperature Range--------------------------------------------------------------------------------------------
ESD Susceptibility (Note 3)
HBM (Human Body Model)----------------------------------------------------------------------------------------------
MM (Machine Model)-----------------------------------------------------------------------------------------------------
6V
6V
0.4W
0.3W
250°C/W
333°C/W
260°C
150°C
−
65°C to 150°C
2kV
200V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage------------------------------------------------------------------------------------------------------ 2.2V to 5.5V
Junction Temperature Range--------------------------------------------------------------------------------------------
−40°C to 125°C
Ambient Temperature Range--------------------------------------------------------------------------------------------
−40°C to 85°C
Electrical Characteristics
(V
IN
= V
OUT
+ 0.5V, V
EN
= V
IN
, C
IN
= C
OUT
= 1μF (Ceramic), T
A
= 25°C unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
Input Voltage Range
Output Noise Voltage
Output Voltage Accuracy
(Fixed Output Voltage)
Quiescent Current (Note 5)
Standby Current
Current Limit
Dropout Voltage (Note 6)
V
IN
V
ON
V
OUT
I
Q
I
STBY
I
LIM
V
DROP
V
OUT
= 1.5V, C
OUT
= 1F, I
OUT
=
0mA, C
SS
= 1nF
I
OUT
= 10mA
V
EN
= 5V, I
OUT
= 0mA
V
EN
= 0V
R
LOAD
= 0, 2.2V V
IN
< 2.6V
R
LOAD
= 0, 2.7V V
IN
5.5V
I
OUT
= 400mA, 2.2V V
IN
< 2.7V
I
OUT
= 500mA, 2.7V V
IN
5.5V
1mA < I
OUT
< 400mA
2.2V V
IN
< 2.7V
1mA < I
OUT
< 500mA
2.7V V
IN
5.5V
V
OUT
= 2.5V, C
SS
= 1nF
2.2 -- 5.5 V
-- 40 -- V
RMS
2 0 +2 %
--
--
0.4
0.5
--
--
25
0.7
0.7
0.8
160
250
50
1.5
1.05
1.05
320
400
A
A
A
mV
Load Regulation (Note 7)
(Fixed Output Voltage)
Soft Start Time
V
LOAD
-- -- 0.6
%
-- -- 1
-- 0.7 1 ms
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
3
RT9020
Parameter
EN Threshold
Symbol
Test Conditions Min Typ Max Unit
0
1.6
--
--
0.6
5.5
V
Logic-Low Voltage V
IL
Logic-High Voltage V
IH
Enable Pin Current
Power Supply
f = 10kHz
Rejection Rate
Line Regulation
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
I
EN
PSRR
V
LINE
I
OUT
= 10mA
V
IN
= (V
OUT
+0.5) to 5.5V,
I
OUT
= 1mA
0.1 1 5 A
-- 55 -- dB
-- 0.01 0.2 %/V
-- 170 --
C
-- 30 --
T
SD
T
SD
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. θ
JA
is measured at T
A
= 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by I
Q
= I
IN
- I
OUT
under no
load condition (I
OUT
= 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin
current.
Note 6. The dropout voltage is defined as V
IN
-V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
- 100mV.
Note 7. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load
regulation in the load range from 10mA to 500mA.
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
4
DS9020-07 July 2017
RT9020
Typical Operating Characteristics
(C
IN
= C
OUT
= 1uF/X7R, C
SS
= 1nF, unless otherwise specified)
Output Voltage vs. Temperature
3.40
3.35
3.30
3.25
3.20
3.15
3.10
-50-255
Dropout Voltage vs. Load Current
300
250
V
IN
= 5.0V
V
OUT
= 3.3V
T
J
= 125°C
D
r
o
p
o
u
t
V
o
l
t
a
g
e
(
m
V
)
O
u
t
p
u
t
V
o
l
t
a
g
e
(
V
)
200
T
J
= 25°C
150
100
50
0
0500
T
J
= -40°C
Temperature
(°C)
Load Current (mA)
Quiescent Current vs. Temperature
50
Soft Start Time
10000
10
V
IN
= 4.5V, V
OUT
= 3.3V
V
IN
= 5.0V, V
OUT
= 3.3V
Q
u
i
e
s
c
e
n
t
C
u
r
r
e
n
t
(
u
A
)
m
S
o
f
t
S
t
a
r
t
T
i
m
e
(
u
s
s
)
)
40
8000
8
30
6000
6
20
4000
4
10
2000
2
0
-50-255
0
Temperature
(°C)
C
ss
(nF)
Start Up
V
IN
= 4.5V, V
OUT
= 3.1V, C
SS
= 22nF, No Load
EN Pin Shutdown Response
V
IN
= 4.5V, V
OUT
= 3.3V, No Load
V
EN
(5V/Div)
V
EN
(5V/Div)
V
OUT
(1V/Div)
I
IN
(50mA/Div)
Time (10ms/Div)
V
OUT
(2V/Div)
I
IN
(50mA/Div)
Time (5ms/Div)
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
5
RT9020
Load Transient Response
V
IN
= 4.5V, V
OUT
= 3.1V, I
LOAD
= 1mA to 300mA
Load Transient Response
V
IN
= 4.5V, V
OUT
= 3.1V, I
LOAD
= 50mA to 250mA
I
LOAD
(200mA/Div)
I
LOAD
(200mA/Div)
V
OUT
(100mV/Div)
V
OUT
(100mV/Div)
Time (250μs/Div)
Time (10μs/Div)
Line Transient Response
V
IN
= 4V to 5V, V
OUT
= 3.1V, I
LOAD
= 10mA
Line Transient Response
V
IN
= 4V to 5V, V
OUT
= 3.1V, I
LOAD
= 100mA
V
IN
(V)
4
5
V
IN
(V)
4
5
V
OUT
(10mV/Div)
V
OUT
(10mV/Div)
Time (100μs/Div)Time (100μs/Div)
PSRR
20
10
0
-10
Noise
V
IN
= 4.5V (By battery), V
OUT
= 3.3V, No Load
300
I
LOAD
= 100mA
200
V
IN
= 4.5V, V
OUT
= 3.3V
V
IN,AC
= 100m V
P-P
N
o
i
s
e
(
μ
V
/
D
i
v
)
I
LOAD
= 10mA
P
S
R
R
(
d
B
)
100
0
-100
-200
-300
-20
-30
-40
-50
-60
-70
0.01 0.1 1 10 100 1000
100
Time (10ms/Div)
Frequency (Hz)
Frequency (kHz)
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
6
DS9020-07 July 2017
RT9020
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9020 must be carefully selected for regulator
stability and performance. The recommended input and
output capacitors should be 1μF or greater X7R/X5R
input capacitor must be located a distance
not more than 0.5 inch from the input pin of the IC and
returned to a clean analog ground. The capacitor with larger
value and lower ESR (equivalent series resistance) provides
better PSRR and line-transient response.
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9020 is designed specifically to work
with low ESR ceramic output capacitor in space-saving
and performance consideration. Using a ceramic capacitor
whose value is at least 1μF with ESR > 20mΩ on the
RT9020 output ensures stability. The RT9020 still works
well with output capacitor of other types due to the wide
stable ESR range. Figure 1. shows the curves of allowable
ESR range as a function of load current for various output
capacitor values. Output capacitor of larger capacitance
can reduce noise and improve load transient response,
stability, and PSRR. The output capacitor should be located
not more than 0.5 inch from the VOUT pin of the RT9020
and returned to a clean analog ground.
Enable
The RT9020 goes into shutdown mode when the EN pin
is in a logic low condition. During this condition, the
RT9020 has an EN pin to turn on or turn off regulator,
When the EN pin is logic high, the regulator will be turned
on. The supply current in shutdown mode is as low as
0.7μA typically. The EN pin may
be directly tied to V
IN
to
keep the part on.
PSRR
The power supply rejection ratio (PSRR) is defined as the
gain from the input to output divided by the gain from the
supply to the output. The PSRR is found to be
PSRR 20log
∆Gain Error
∆Supply
Note that when heavy load measuring, Δsupply will cause
Δtemperature. And Δtemperature will cause Δoutput
voltage change. So the heavy load PSRR measuring
includes temperature effect.
Current limit
The RT9020 contains an independent current limiter, which
monitors and controls the pass transistor's gate voltage,
limiting the output current to 0.7A (typ.). The output can
be shorted to ground indefinitely without damaging the
part.
Thermal Considerations
Region of Stable C
OUT
ESR vs. Load Current
100
R
e
g
i
o
n
o
f
S
t
a
b
l
e
C
O
U
T
E
S
R
(
Ω
)
10
Unstable Range
1
Stable Range
0.1
Thermal protection limits power dissipation in RT9020.
When the operation junction temperature exceeds 170°C,
the OTP circuit starts the thermal shutdown function and
turns the pass element off. The pass element turn on again
after the junction temperature cools by 30°C.
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is :
P
D
= (V
IN
− V
OUT
) x I
OUT
+ V
IN
x I
Q
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junction to ambient. The maximum power dissipation can
0.01
Unstable Range by Simulation
RT9020-33PB, V
IN
= 5V
C
IN
= C
OUT
= 1μF/X7R
0500
0.001
Load Current (mA)
Figure 1
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
7
RT9020
be calculated by following formula :
P
D(MAX)
= ( T
J(MAX)
− T
A
) /θ
JA
Where T
J(MAX)
is the maximum operation junction
temperature, T
A
is the ambient temperature and the θ
JA
is
the junction to ambient thermal resistance.
For recommended operating conditions specification,
where T
J(MAX)
is the maximum junction temperature of the
die (125°C) and T
A
is the operated ambient temperature.
The junction to ambient thermal resistance θ
JA
(θ
JA
is
layout dependent) for SOT-23-5 package is 250°C/W and
SC-70-5 package is 333°C/W on the standard JEDEC
51-3 single-layer thermal test board. The maximum power
dissipation at T
A
= 25°C can be calculated by following
formula :
P
D(MAX)
= (125°C − 25°C) / 250 = 0.400W for SOT-23-5
packages
P
D(MAX)
= (125°C − 25°C) / 333 = 0.300W for SC-70-5
packages
The maximum power dissipation depends on operating
ambient temperature for fixed T
J(MAX)
and thermal
resistance θ
JA
. The Figure 2 of derating curves allows the
designer to see the effect of rising ambient temperature
on the maximum power allowed.
0.7
0.6
Single Layer PCB
P
o
w
e
r
D
i
s
s
i
p
a
t
i
o
n
(
W
)
0.5
SOT-23-5
0.4
0.3
0.2
0.1
0
012.52537.55062.57587.5100113125
SC-70-5
Ambient Temperature
(°C)
Figure 2. Derating Curve of Maximum Power Dissipation
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
8
DS9020-07 July 2017
RT9020
Outline Dimension
H
D
L
C
B
b
A
A1
e
Symbol
A
A1
B
b
C
D
e
Dimensions In Millimeters Dimensions In Inches
Min Max Min Max
0.889
0.000
1.397
0.356
2.591
2.692
0.838
1.295
0.152
1.803
0.559
2.997
3.099
1.041
0.035
0.000
0.055
0.014
0.102
0.106
0.033
0.051
0.006
0.071
0.022
0.118
0.122
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
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
9
RT9020
H
D
L
C
B
b
A
A1
e
Symbol
Dimensions In Millimeters Dimensions In Inches
Min Max Min Max
A 0.800 1.100 0.031 0.044
A1 0.000 0.100 0.000 0.004
B 1.150 1.350 0.045 0.054
b 0.150 0.400 0.006 0.016
C 1.800 2.450 0.071 0.096
D 1.800 2.250 0.071 0.089
e 0.650 0.026
H 0.080 0.260 0.003 0.010
L 0.210 0.460 0.008 0.018
SC-70-5 Surface Mount Package
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1
st
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.
10
DS9020-07 July 2017
2024年9月24日发(作者：张志新)
®
RT9020
500mA, Low Dropout, Low Noise Ultra-Fast With Soft Start
CMOS LDO Regulator
General Description
The RT9020 is a high-performance, 500mA LDO regulator,
offering extremely high PSRR and ultra-low dropout, ideal
for portable RF and wireless applications with demanding
performance and space requirements.
The RT9020 quiescent current is as low as 25μA, further
prolonging the battery life. The RT9020 also works with
low-ESR ceramic capacitors, reducing the amount of board
space necessary for power applications, critical in hand-
held wireless devices.
The RT9020 consumes typical 0.7μA in shutdown mode
and has fast turn-on time less than 70μs (without C
SS
).
The other features include ultra-low dropout voltage, high
output accuracy, current limiting protection, and high ripple
rejection ratio. Tiny packages SOT-23-5 and SC-70-5 are
available.
Features
Wide Operating Voltage Ranges : 2.2V to 5.5V
Low Dropout : 250mV at 500mA
5mA Discharge Current of V
OUT
when IC Shutdown
Ultra-Low-Noise for DSC Application
Ultra-Fast Response in Line/Load Transient
Current Limiting Protection
Thermal Shutdown Protection
High Power Supply Rejection Ratio
Output Only 1
μ
F Capacitor Required for Stability
TTL-Logic-Controlled Shutdown Input
RoHS Compliant and 100% Lead (Pb)-Free
Moisture Sensitivity Level : Level 3
Applications
Digital Still Camera
CDMA/GSM Cellular Handsets
Portable Information Appliances
Laptop, Palmtops, Notebook Computers
Mini PCI & PCI-Express Cards
PCMCIA & New Cards
Ordering Information
RT9020
-
Package Type
B : SOT-23-5
U5 : SC-70-5
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Fixed Output Voltage
12 : 1.2V
15 : 1.5V
16 : 1.6V
:
32 : 3.2V
33 : 3.3V
1B : 1.25V
1H : 1.85V
2H : 2.85V
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Pin Configuration
TOP VIEW
VOUT
5
2
SS
4
3
VIN
GNDEN
SOT-23-5 / SC-70-5
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
1
RT9020
Typical Application Circuit
V
IN
VIN
C
IN
1uF/
X7R
VOUT
RT9020
C
OUT
1uF/
X7R
V
OUT
Chip Enable
EN
GND
SS
C
SS
0.5nF
Functional Pin Description
Pin Number Pin Name Pin Function
1 VIN Supply input.
2 GND Common ground.
Enable input logic, active high. When the EN goes to a logic low, the device will
3 EN
be shutdown.
4 SS Soft start.
5 VOUT Regulator output.
Functional Block Diagram
SS
EN
1µA
POR
OTP
V
REF
Current
Limit
VIN
-
+
MOS
Driver
VOUT
GND
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
2
DS9020-07 July 2017
RT9020
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage------------------------------------------------------------------------------------------------------
EN Input Voltage-----------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-5--------------------------------------------------------------------------------------------------------------------
SC-70-5----------------------------------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
SOT-23-5, θ
JA
---------------------------------------------------------------------------------------------------------------
SC-70-5, θ
JA
----------------------------------------------------------------------------------------------------------------
Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------------
Junction Temperature-----------------------------------------------------------------------------------------------------
Storage Temperature Range--------------------------------------------------------------------------------------------
ESD Susceptibility (Note 3)
HBM (Human Body Model)----------------------------------------------------------------------------------------------
MM (Machine Model)-----------------------------------------------------------------------------------------------------
6V
6V
0.4W
0.3W
250°C/W
333°C/W
260°C
150°C
−
65°C to 150°C
2kV
200V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage------------------------------------------------------------------------------------------------------ 2.2V to 5.5V
Junction Temperature Range--------------------------------------------------------------------------------------------
−40°C to 125°C
Ambient Temperature Range--------------------------------------------------------------------------------------------
−40°C to 85°C
Electrical Characteristics
(V
IN
= V
OUT
+ 0.5V, V
EN
= V
IN
, C
IN
= C
OUT
= 1μF (Ceramic), T
A
= 25°C unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
Input Voltage Range
Output Noise Voltage
Output Voltage Accuracy
(Fixed Output Voltage)
Quiescent Current (Note 5)
Standby Current
Current Limit
Dropout Voltage (Note 6)
V
IN
V
ON
V
OUT
I
Q
I
STBY
I
LIM
V
DROP
V
OUT
= 1.5V, C
OUT
= 1F, I
OUT
=
0mA, C
SS
= 1nF
I
OUT
= 10mA
V
EN
= 5V, I
OUT
= 0mA
V
EN
= 0V
R
LOAD
= 0, 2.2V V
IN
< 2.6V
R
LOAD
= 0, 2.7V V
IN
5.5V
I
OUT
= 400mA, 2.2V V
IN
< 2.7V
I
OUT
= 500mA, 2.7V V
IN
5.5V
1mA < I
OUT
< 400mA
2.2V V
IN
< 2.7V
1mA < I
OUT
< 500mA
2.7V V
IN
5.5V
V
OUT
= 2.5V, C
SS
= 1nF
2.2 -- 5.5 V
-- 40 -- V
RMS
2 0 +2 %
--
--
0.4
0.5
--
--
25
0.7
0.7
0.8
160
250
50
1.5
1.05
1.05
320
400
A
A
A
mV
Load Regulation (Note 7)
(Fixed Output Voltage)
Soft Start Time
V
LOAD
-- -- 0.6
%
-- -- 1
-- 0.7 1 ms
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
3
RT9020
Parameter
EN Threshold
Symbol
Test Conditions Min Typ Max Unit
0
1.6
--
--
0.6
5.5
V
Logic-Low Voltage V
IL
Logic-High Voltage V
IH
Enable Pin Current
Power Supply
f = 10kHz
Rejection Rate
Line Regulation
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
I
EN
PSRR
V
LINE
I
OUT
= 10mA
V
IN
= (V
OUT
+0.5) to 5.5V,
I
OUT
= 1mA
0.1 1 5 A
-- 55 -- dB
-- 0.01 0.2 %/V
-- 170 --
C
-- 30 --
T
SD
T
SD
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. θ
JA
is measured at T
A
= 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by I
Q
= I
IN
- I
OUT
under no
load condition (I
OUT
= 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin
current.
Note 6. The dropout voltage is defined as V
IN
-V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
- 100mV.
Note 7. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load
regulation in the load range from 10mA to 500mA.
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
4
DS9020-07 July 2017
RT9020
Typical Operating Characteristics
(C
IN
= C
OUT
= 1uF/X7R, C
SS
= 1nF, unless otherwise specified)
Output Voltage vs. Temperature
3.40
3.35
3.30
3.25
3.20
3.15
3.10
-50-255
Dropout Voltage vs. Load Current
300
250
V
IN
= 5.0V
V
OUT
= 3.3V
T
J
= 125°C
D
r
o
p
o
u
t
V
o
l
t
a
g
e
(
m
V
)
O
u
t
p
u
t
V
o
l
t
a
g
e
(
V
)
200
T
J
= 25°C
150
100
50
0
0500
T
J
= -40°C
Temperature
(°C)
Load Current (mA)
Quiescent Current vs. Temperature
50
Soft Start Time
10000
10
V
IN
= 4.5V, V
OUT
= 3.3V
V
IN
= 5.0V, V
OUT
= 3.3V
Q
u
i
e
s
c
e
n
t
C
u
r
r
e
n
t
(
u
A
)
m
S
o
f
t
S
t
a
r
t
T
i
m
e
(
u
s
s
)
)
40
8000
8
30
6000
6
20
4000
4
10
2000
2
0
-50-255
0
Temperature
(°C)
C
ss
(nF)
Start Up
V
IN
= 4.5V, V
OUT
= 3.1V, C
SS
= 22nF, No Load
EN Pin Shutdown Response
V
IN
= 4.5V, V
OUT
= 3.3V, No Load
V
EN
(5V/Div)
V
EN
(5V/Div)
V
OUT
(1V/Div)
I
IN
(50mA/Div)
Time (10ms/Div)
V
OUT
(2V/Div)
I
IN
(50mA/Div)
Time (5ms/Div)
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
5
RT9020
Load Transient Response
V
IN
= 4.5V, V
OUT
= 3.1V, I
LOAD
= 1mA to 300mA
Load Transient Response
V
IN
= 4.5V, V
OUT
= 3.1V, I
LOAD
= 50mA to 250mA
I
LOAD
(200mA/Div)
I
LOAD
(200mA/Div)
V
OUT
(100mV/Div)
V
OUT
(100mV/Div)
Time (250μs/Div)
Time (10μs/Div)
Line Transient Response
V
IN
= 4V to 5V, V
OUT
= 3.1V, I
LOAD
= 10mA
Line Transient Response
V
IN
= 4V to 5V, V
OUT
= 3.1V, I
LOAD
= 100mA
V
IN
(V)
4
5
V
IN
(V)
4
5
V
OUT
(10mV/Div)
V
OUT
(10mV/Div)
Time (100μs/Div)Time (100μs/Div)
PSRR
20
10
0
-10
Noise
V
IN
= 4.5V (By battery), V
OUT
= 3.3V, No Load
300
I
LOAD
= 100mA
200
V
IN
= 4.5V, V
OUT
= 3.3V
V
IN,AC
= 100m V
P-P
N
o
i
s
e
(
μ
V
/
D
i
v
)
I
LOAD
= 10mA
P
S
R
R
(
d
B
)
100
0
-100
-200
-300
-20
-30
-40
-50
-60
-70
0.01 0.1 1 10 100 1000
100
Time (10ms/Div)
Frequency (Hz)
Frequency (kHz)
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
6
DS9020-07 July 2017
RT9020
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9020 must be carefully selected for regulator
stability and performance. The recommended input and
output capacitors should be 1μF or greater X7R/X5R
input capacitor must be located a distance
not more than 0.5 inch from the input pin of the IC and
returned to a clean analog ground. The capacitor with larger
value and lower ESR (equivalent series resistance) provides
better PSRR and line-transient response.
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9020 is designed specifically to work
with low ESR ceramic output capacitor in space-saving
and performance consideration. Using a ceramic capacitor
whose value is at least 1μF with ESR > 20mΩ on the
RT9020 output ensures stability. The RT9020 still works
well with output capacitor of other types due to the wide
stable ESR range. Figure 1. shows the curves of allowable
ESR range as a function of load current for various output
capacitor values. Output capacitor of larger capacitance
can reduce noise and improve load transient response,
stability, and PSRR. The output capacitor should be located
not more than 0.5 inch from the VOUT pin of the RT9020
and returned to a clean analog ground.
Enable
The RT9020 goes into shutdown mode when the EN pin
is in a logic low condition. During this condition, the
RT9020 has an EN pin to turn on or turn off regulator,
When the EN pin is logic high, the regulator will be turned
on. The supply current in shutdown mode is as low as
0.7μA typically. The EN pin may
be directly tied to V
IN
to
keep the part on.
PSRR
The power supply rejection ratio (PSRR) is defined as the
gain from the input to output divided by the gain from the
supply to the output. The PSRR is found to be
PSRR 20log
∆Gain Error
∆Supply
Note that when heavy load measuring, Δsupply will cause
Δtemperature. And Δtemperature will cause Δoutput
voltage change. So the heavy load PSRR measuring
includes temperature effect.
Current limit
The RT9020 contains an independent current limiter, which
monitors and controls the pass transistor's gate voltage,
limiting the output current to 0.7A (typ.). The output can
be shorted to ground indefinitely without damaging the
part.
Thermal Considerations
Region of Stable C
OUT
ESR vs. Load Current
100
R
e
g
i
o
n
o
f
S
t
a
b
l
e
C
O
U
T
E
S
R
(
Ω
)
10
Unstable Range
1
Stable Range
0.1
Thermal protection limits power dissipation in RT9020.
When the operation junction temperature exceeds 170°C,
the OTP circuit starts the thermal shutdown function and
turns the pass element off. The pass element turn on again
after the junction temperature cools by 30°C.
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is :
P
D
= (V
IN
− V
OUT
) x I
OUT
+ V
IN
x I
Q
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junction to ambient. The maximum power dissipation can
0.01
Unstable Range by Simulation
RT9020-33PB, V
IN
= 5V
C
IN
= C
OUT
= 1μF/X7R
0500
0.001
Load Current (mA)
Figure 1
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
7
RT9020
be calculated by following formula :
P
D(MAX)
= ( T
J(MAX)
− T
A
) /θ
JA
Where T
J(MAX)
is the maximum operation junction
temperature, T
A
is the ambient temperature and the θ
JA
is
the junction to ambient thermal resistance.
For recommended operating conditions specification,
where T
J(MAX)
is the maximum junction temperature of the
die (125°C) and T
A
is the operated ambient temperature.
The junction to ambient thermal resistance θ
JA
(θ
JA
is
layout dependent) for SOT-23-5 package is 250°C/W and
SC-70-5 package is 333°C/W on the standard JEDEC
51-3 single-layer thermal test board. The maximum power
dissipation at T
A
= 25°C can be calculated by following
formula :
P
D(MAX)
= (125°C − 25°C) / 250 = 0.400W for SOT-23-5
packages
P
D(MAX)
= (125°C − 25°C) / 333 = 0.300W for SC-70-5
packages
The maximum power dissipation depends on operating
ambient temperature for fixed T
J(MAX)
and thermal
resistance θ
JA
. The Figure 2 of derating curves allows the
designer to see the effect of rising ambient temperature
on the maximum power allowed.
0.7
0.6
Single Layer PCB
P
o
w
e
r
D
i
s
s
i
p
a
t
i
o
n
(
W
)
0.5
SOT-23-5
0.4
0.3
0.2
0.1
0
012.52537.55062.57587.5100113125
SC-70-5
Ambient Temperature
(°C)
Figure 2. Derating Curve of Maximum Power Dissipation
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
8
DS9020-07 July 2017
RT9020
Outline Dimension
H
D
L
C
B
b
A
A1
e
Symbol
A
A1
B
b
C
D
e
Dimensions In Millimeters Dimensions In Inches
Min Max Min Max
0.889
0.000
1.397
0.356
2.591
2.692
0.838
1.295
0.152
1.803
0.559
2.997
3.099
1.041
0.035
0.000
0.055
0.014
0.102
0.106
0.033
0.051
0.006
0.071
0.022
0.118
0.122
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
Copyright 2017 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
©
DS9020-07 July
9
RT9020
H
D
L
C
B
b
A
A1
e
Symbol
Dimensions In Millimeters Dimensions In Inches
Min Max Min Max
A 0.800 1.100 0.031 0.044
A1 0.000 0.100 0.000 0.004
B 1.150 1.350 0.045 0.054
b 0.150 0.400 0.006 0.016
C 1.800 2.450 0.071 0.096
D 1.800 2.250 0.071 0.089
e 0.650 0.026
H 0.080 0.260 0.003 0.010
L 0.210 0.460 0.008 0.018
SC-70-5 Surface Mount Package
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1
st
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.
10
DS9020-07 July 2017