Si9181
Vishay Siliconix
Micropower 350-mA CMOS LDO Regulator
With Error Flag/Power-On-Reset
FEATURES
Low 150-mV Dropout at 350-mA Load
Guaranteed 350-mA Output Current
600-mA Peak Output Current Capability
Uses Low ESR Ceramic Output Capacitor
Fast Load and Line Transient Response
Only 100-mV(rms) Noise With Noise Bypass
Capacitor
D
1-mA Maximum Shutdown Current
D
Built-in Short Circuit and Thermal Protection
D
Out-Of-Regulation Error Flag (Power Good or POR)
D
D
D
D
D
D
D
Fixed 1.5-V, 1.8-V, 2.0-V, 2.5-V, 2.8-V, 2.85-V, 2.9 V,
3.0-V, 3.3-V, 5.0-V, or Adjustable Output Voltage
Options
D
Other Output Voltages Available by Special Order
APPLICATIONS
D
Cellular Phones
D
Laptop and Palm Computers
D
PDA, Digital Still Cameras
DESCRIPTION
The Si9181 is a 350-mA CMOS LDO (low dropout) voltage
regulator. The device features ultra low ground current and
dropout voltage to prolong battery life in portable electronics.
The Si9181 offers line/load transient response and ripple
rejection superior to that of bipolar or BiCMOS LDO regulators.
The device is designed to maintain regulation while delivering
600-mA peak current. This is useful for systems that have high
surge current upon turn-on. The Si9181 is designed to drive
the lower cost ceramic, as well as tantalum, output capacitors.
The device is guaranteed stable from maximum load current
down to 0-mA load. In addition, an external noise bypass
capacitor connected to the device’s C
NOISE
pin will lower the
LDO’s output noise for low noise applications.
The Si9181 also includes an out-of-regulation error flag. When
the output voltage is 5% below its nominal output voltage, the
error flag output goes low. If a capacitor is connected to the
device’s delay pin, the error flag output pin will generate a
delayed power-on-reset signal.
The Si9181 is available in both standard and lead (Pb)-free
packages.
TYPICAL APPLICATIONS CIRCUITS
1
2
3
V
IN
2.2
mF
GND
4
8
7
6
5
2.2
mF
V
OUT
V
IN
2.2
mF
GND
1
2
3
4
8
7
6
5
V
OUT
2.2
mF
C
NOISE
DELAY
GND
V
IN
SD
ERROR
SENSE/ADJ
V
OUT
C
NOISE
DELAY
GND
V
IN
SD
ERROR
SENSE/ADJ
V
OUT
Si9181
FIGURE 1.
Fixed Output
Si9181
FIGURE 2.
Adjustable Output
1
0.1
mF
2
0.1
mF
3
4
C
NOISE
DELAY
GND
V
IN
SD
ERROR
8
7
6
5
2.2
mF
1 MW
ON/OFF
POR
V
OUT
SENSE/ADJ
V
OUT
V
IN
2.2
mF
GND
Si9181
FIGURE 3.
Low Noise, Full Features Application
Document Number: 71119
S-40694—Rev. D, 19-Apr-04
www.vishay.com
1
VISHAY [ VISHAY TELEFUNKEN ]
