150mA LDO Regulator with PGOOD
The RT9181 is a low dropout voltage regulator with an
output 2% accuracy and supply a continuous 150mA
current within operating range from a +3V to +5.5V input.
The power good function monitors the output voltage
and indicates by pulling low the power good output (open
The RT9181 requires a small output capacitor with low
ESR for stabilizing output voltage. The device also
minimizes output overshoot during power up.
The RT9181 uses an internal PMOS as the pass device,
which consumes 160μA supply current independent of
load and dropout conditions. The EN pin controls the
output and consumes no input bias current. Other
features include current limiting, over temperature
protection, and under voltage lockout.
z Low Dropout Voltage Regulator
z Up to 150mA Output Current
z Power Good (PGOOD) Function
z Chip Enable/Shutdown Function
z Load Independent, Low Quiescent Current, 160μA
z Current Limiting and Thermal Protection
z Under Voltage Lockout (UVLO)
z Low Variation Due to Load and Line Regulation
z Output Stable with Low ESR Capacitors
z SOT-23-5 Package
z RoHS Compliant and 100% Lead (Pb)-Free
z Processor Power-Up Sequencing
z Laptop, Notebook, and Palmtop Computers
B : SOT-23-5
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
Default : 1.2V
18 : 1.8V
RichTek Pb-free and Green 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.
`100% matte tin (Sn) plating.
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
VIN 1 5 VOUT
EN 3 4 PGOOD
Typical Application Circuit
1 VIN PGOOD 4
Chip Enable 3 EN VOUT 5
DS9181-14 March 2007