®
RT9078
2μA I
Q
, 300mA Low-Dropout Linear Regulator
μ
General Description
The RT9078 is a low-dropout (LDO) voltage regulator with
enable function that operates from 1.2V to 5.5V. It provides
up to 300mA of output current and offers low-power
operation in miniaturized packaging.
The features of low quiescent current as low as 2μA and
almost zero disable current is ideal for powering the battery
equipment to a longer service life. The RT9078 is stable
with the ceramic output capacitor over its wide input range
from 1.2V to 5.5V and the entire range of output load
current (0mA to 300mA).
Features
μ
2μA Ground Current at no Load
PSRR = 75dB at 1kHz
Adjustable Output Voltage Available by Specific
Application
±
2% Output Accuracy
300mA (V
IN
≥
1.7V) Output Current with EN
Low (0.1μA) Disable Current
μ
1.2V to 5.5V Operating Input Voltage
Dropout Voltage : 0.15V at 300mA when V
OUT
≥
3V
Support Fixed Output Voltage 0.8V, 1.0V, 1.05V, 1.1V,
1.2V, 1.25V, 1.3V, 1.5V, 1.8V, 1.85V, 2.5V, 2.8V, 2.85V,
3V, 3.1V, 3.3V, 3.45V
Stable with Ceramic or Tantalum Capacitor
Current Limit Protection
Over Temperature Protection
TSOT-23-5 and ZQFN-4L 1x1 (ZDFN-4L 1x1) Packages
Available
Pin Configuration
(TOP VIEW)
VOUT
5
2
SNS/NC
4
3
VIN GND EN
Applications
TSOT-23-5
VOUT
1
4
VIN
Portable, Battery Powered Equipment
Ultra Low Power Microcontrollers
Notebook Computers
SGND
GND
2
5
3
EN
ZQFN-4L 1x1 (ZDFN-4L 1x1)
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9078-14 August 2018
www.richtek.com
1
RT9078
Ordering Information
RT9078/N-
Pin 1 Orientation
***
(2) : Quadrant 2, Follow EIA-481-D
Package Type
J5 : TSOT-23-5
QZ : ZQFN-4L 1x1 (Z-Type)
(ZDFN-4L 1x1)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Output Voltage
08 : 0.8V
:
33 : 3.3V
1B : 1.25V
1H : 1.85V
2H : 2.85V
1K : 1.05V
3D : 3.45V (ZQFN-4L 1x1 only)
Special Request : Any voltage between
0.8V and 3.3V under specific business
agreement
Pin Function
RT9078 : Without SNS Pin
RT9078N : With SNS Pin**
Note :
***Empty means Pin1 orientation is Quadrant 1
**Available for output target adjustment (Ex : RT9078N-08GJ5
with 0.8V reference level for output target adjustment)
Richtek products are :
½
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
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.
½
Functional Pin Description
Pin No.
TSOT-23-5 ZQFN-4L 1x1 (ZDFN-4L 1x1)
1
2
3
4
5
--
4
2
3
--
1
5 (Exposed Pad)
Pin Name
VIN
GND
EN
SNS
NC
VOUT
SGND
Supply voltage input.
Ground.
Enable control input.
Output voltage sense. (RT9078N only)
No internal connection.
Output of the regulator.
Substrate of chip. Leave floating or tie to GND.
is a registered trademark of Richtek Technology Corporation.
Pin Function
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
DS9078-14 August 2018
RT9078
Functional Block Diagram
VIN
GND
Current/Thermal
Sense
(without sense
function)
VOUT
SNS
(with sense
function)
R1
EN
R2
+
-
EN
Bandgap
Reference
Operation
Basic operation
The RT9078 is a low quiescent current linear regulator
designed especially for low external components system.
The input voltage range is from 1.2V to 5.5V.
The minimum required output capacitance for stable
operation is 1μF capacitance after consideration of the
temperature and voltage coefficient of the capacitor.
Output Transistor
The RT9078 builds in a P-MOSFET output transistor which
provides a low switch-on resistance for low dropout voltage
applications.
Error Amplifier
The Error Amplifier compares the internal reference voltage
with the output feedback voltage from the internal divider,
and controls the Gate voltage of P-MOSFET to support
good line regulation and load regulation at output voltage.
Enable
The RT9078 delivers the output power when it is set to
enable state. When it works in disable state, there is no
output power and the operation quiescent current is almost
zero.
Current-Limit Protection
The RT9078 provides current limit function to prevent the
device from damages during over-load or shorted-circuit
condition. This current is detected by an internal sensing
transistor.
Over-Temperature Protection
The over-temperature protection function will turn off the
P-MOSFET when the junction temperature exceeds 150°C
(typ.), and the output current exceeds 80mA. Once the
junction temperature cools down by approximately 20°C,
the regulator will automatically resume operation.
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9078-14 August 2018
www.richtek.com
3
RT9078
Absolute Maximum Ratings
(Note 1)
−0.3V
to 6.5V
−6.5V
to 0.3V
0.43W
0.44W
230.6°C/W
VIN, VOUT, SNS, EN to GND -------------------------------------------------------------------------------------------
VOUT to VIN ----------------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
TSOT-23-5 -------------------------------------------------------------------------------------------------------------------
ZQFN-4L 1x1 (ZDFN-4L 1x1) --------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
TSOT-23-5,
θ
JA
-------------------------------------------------------------------------------------------------------------
TSOT-23-5,
θ
JC
------------------------------------------------------------------------------------------------------------- 21.8°C/W
ZQFN-4L 1x1 (ZDFN-4L 1x1),
θ
JA
-------------------------------------------------------------------------------------- 226°C/W
ZQFN-4L 1x1 (ZDFN-4L 1x1),
θ
JC
------------------------------------------------------------------------------------- 43°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
(Note 4)
Recommended Operating Conditions
Input Voltage, VIN --------------------------------------------------------------------------------------------------------- 1.2V to 5.5V
Junction Temperature Range --------------------------------------------------------------------------------------------
−40°C
to 125°C
Ambient Temperature Range --------------------------------------------------------------------------------------------
−40°C
to 85°C
Electrical Characteristics
(V
OUT
+ 1 < V
IN
< 5.5V, T
A
= 25°C, unless otherwise specified)
Parameter
Fixed Output Voltage Range
DC Output Accuracy
SNS Reference Voltage (for
RT9078N-08GJ5 only)
Symbol
V
OUT
Test Conditions
I
LOAD
= 1mA
Min
0.8
2
0.784
--
--
--
--
--
--
--
--
--
--
--
Typ
--
--
0.8
0.7
0.5
0.4
0.3
0.24
0.21
0.18
0.16
0.15
0.16
2
Max
3.45
2
0.816
0.97
0.92
0.57
0.47
0.33
0.3
0.25
0.23
0.2
0.2
4
Unit
V
%
V
V
REF
I
LOAD
= 1mA
0.8V
V
OUT
1.05V
1.05V
V
OUT
1.2V
1.2V
V
OUT
1.5V
1.5V
V
OUT
1.8V
Dropout Voltage
(I
LOAD
= 300mA)
(Note 5)
V
DROP
1.8V
V
OUT
2.1V
2.1V
V
OUT
2.5V
2.5V
V
OUT
2.8V
2.8V
V
OUT
3V
3V
V
OUT
V
Dropout Voltage
(I
LOAD
= 200mA)
(Note 5)
V
DROP
I
Q
1.8V
V
OUT
2.1V
I
LOAD
= 0mA, V
OUT
5.5V
V
IN
V
OUT
+ V
DROP
V
A
V
CC
Consumption Current
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS9078-14 August 2018
RT9078
Parameter
Shutdown GND Current
(Note 6)
Shutdown Leakage Current
(Note 6)
EN Input Current
Line Regulation
Load Regulation
Power Supply Rejection Ratio
I
EN
LINE
LOAD
PSRR
Symbol
V
EN
= 0V
V
EN
= 0V, V
OUT
= 0V
V
EN
= 5.5V
1.2V
V
IN
1.5V
I
LOAD
= 1mA
1.5V
V
IN
1.8V
1.8V
V
IN
5.5V
1mA < I
LOAD
< 300mA
V
IN
= 3V, I
LOAD
= 50mA,
C
OUT
= 1F, V
OUT
= 2.5V, f = 1kHz
C
OUT
= 1F,
I
LOAD
= 150mA,
BW = 10Hz to
100kHz,
V
IN
= V
OUT
+ 1V
I
LIM
V
ENH
V
ENL
T
SD
T
SD
EN = 0V, V
OUT
= 0.1V
V
OUT
= 0.8V
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 3.3V
Test Conditions
Min
--
--
--
--
--
--
--
--
--
--
--
--
350
0.5
0.4
--
--
--
Typ
0.1
0.1
--
0.3
0.15
0.13
0.5
75
38
46
48
51
600
0.7
0.65
150
20
80
Max
0.5
0.5
0.1
0.6
0.3
0.35
1
--
--
--
--
--
--
0.9
0.85
--
--
--
mA
V
C
C
V
RMS
%
dB
%
Unit
A
A
A
Output Voltage Noise
Output Current Limit
Enable Threshold
Voltage
Thermal Shutdown
Temperature
Thermal Shutdown Hysteresis
Discharge Resistance
H-Level
L-Level
V
OUT
= 90%V
OUT(Normal)
V
IN
= 5V
V
IN
= 5V
I
LOAD
= 30mA, V
IN
1.5V
Note 1.
Stresses beyond those listed under
“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 in the natural convection at T
A
= 25°C on a two-layer Richtek Evaluation Board for ZQFN-4L 1x1 (ZDFN-
4L1x1) Package.
θ
JA
is measured at T
A
= 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7 for TSOT-23-
5 Package.
Note 3.
Devices are ESD sensitive. Handling precaution is recommended.
Note 4.
The device is not guaranteed to function outside its operating conditions.
Note 5.
The dropout voltage is defined as V
IN
−
V
OUT
, when V
OUT
is 98% of the normal value of V
OUT
.
For the application under following condition :
1.8V
≤
V
OUT
< 2.1V, I
LOAD
= 200mA, T
A
= 85°C, the maximum dropout voltage is guaranteed by design that not over 0.28V.
Note 6.
The specification is tested at wafer stage and guaranteed by design after assembly.
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9078-14 August 2018
www.richtek.com
5
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