RS3221
REV A.2
1 / 15
www.run-ic.com
Low Power, Low Dropout,
200mA Linear Regulators
FEATURES
Low Dropout Voltage
Thermal-Overload Protection
Output Current Limit
10nA Logic-Controlled Shutdown
1μA Low Supply Current
1.7V to 7.5V Input Voltage Range
200mA Output Current
-40°C to +85°C Operating Temperature Range
Available in Green UTDFN-1x1-4, SOT23-5，
SOT23-3, SOT353(SC70-5) and SOT89-3L
(L-Type) Package
APPLICATIONS
• Cellular Telephones
• Camera Modules
• Modems
• HiFi Audio Radio Transceivers
• PLL/Synthesizer, Clocking
• Medium-Current, Noise-Sensitive
Applications
DESCRIPTION
The RS3221 series low-power, low-dropout, CMOS
LDO operate from 1.7V to 7.5V input voltage that can
supply up to 200 mA of output current. Designed to
meet the requirements of analog circuits, the RS3221
series device provides low noise, high PSRR, low
quiescent current, and low line and load transient
response.
The device is designed to work with a 1-µF input and
a 1-µF output ceramic capacitor (no separate noise
bypass capacitor required). An external noise bypass
capacitor connected to the device’s BP pin can further
reduce the noise level.
Other features include a 10nA logic-controlled
shutdown mode, foldback current limit and thermal
shutdown protection.
The RS3221 series is available in Green UTDFN-1x1-
4, SOT23-3, SOT23-5, SOT353(SC70-5) and
SOT89-3L(L-Type) package. It operates over an
ambient temperature range of -40°C to +85°C .
Thermal
Shutdown
Internal
Controller
VREF
Current
Limit
Error
amp
IN
EN BP
OUT
GND
Copyright © 2017,
RUNIC Technology
Thermal
Shutdown
Internal
Controller
VREF
Current
Limit
Error
amp
IN
EN FB
OUT
GND
Copyright © 2017,
RUNIC Technology
RS3221
2 / 15
www.run-ic.com
Pin Configuration and Functions (Top View)
(TOP VIEW)
(TOP VIEW)
3
1
5
IN
EN
OUT
2
GND
4
BP/FB
UTDFN-1×1-4
SOT23-5/SOT353(SC70-5)
UTDFN-1×1-4
I/O
DESCRIPTION
NUMBER
NAME
1
OUT
O
Regulator Output.
2
GND
G
Ground.
3
EN
I
Enable Input. A logic low reduces the supply current to 10nA. Connect to IN for
normal operation.
4
IN
I
Regulator Input. Supply voltage can range from 1.7V to 7.5V. Bypass with a 1μF
capacitor to GND.
Thermal Pad
-
-
Connect the thermal pad to a large-area ground plane. This pad is not an electrical
connection to the device ground.
SOT23-5
/SOT353(SC70-5)
I/O
DESCRIPTION
NUMBER
NAME
1
IN
I
Regulator Input. Supply voltage can range from 1.7V to 7.5V. Bypass with a 1μF
capacitor to GND.
2
GND
G
Ground.
3
EN
I
Enable Input. A logic low reduces the supply current to 10nA. Connect to IN for
normal operation.
4
BP
O
Reference-Noise Bypass (fixed voltage version only). Bypass with a low-leakage
0.01μF ceramic capacitor for reduced noise at the output. The capacitor is
recommended to be placed very close to the pin for high PSRR.
FB
Feedback Pin (adjustable voltage version only). This is used to set the output voltage
of the device.
5
OUT
O
Regulator Output.