SI91821 Datasheet, PDF (1/10 Pages) Vishay Siliconix – Micropower 300-mA CMOS LDO Regulator With Error Flag

Si91821
Vishay Siliconix
Micropower 300-mA CMOS LDO Regulator With Error Flag
FEATURES
D Input Voltage: 2.35−6.0 V
D Fixed 1.8-V, 2.5-V, 2.8-V, 3.0-V, 3.3-V, 5.0-V, or
Adjustable Output Voltage Options
D Low 120-mV Dropout at 300-mA Load
D Guaranteed 300-mA Output Current
D 500-mA Peak Output Current Capability
D Uses Low ESR Ceramic Output Capacitor
D Fast Load and Line Transient Response
D Only 100-mV(rms) Noise With Noise Bypass
Capacitor
Available
D 1-mA Maximum Shutdown Current
D Built-in Short Circuit and Thermal Protection
D Out-Of-Regulation Error Flag (Power_Good)
APPLICATIONS
D Cellular Phones
D Laptop and Palm Computers
D PDA, Digital Still Cameras
DESCRIPTION
The Si91821 is a 300-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 Si91821 offers line and load transient response and ripple
rejection superior to that of bipolar or BiCMOS LDO regulators.
The device is designed to maintain regulation while delivering
500-mA peak current. This is useful for systems that have high
surge current upon turn-on. The Si91821 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 Si91821 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.
The Si91821 is available in both standard and lead (Pb)-free
MSOP-8 packages and is specified to operate over the
industrial temperature range of −40 _C to 85 _C.
TYPICAL APPLICATIONS CIRCUITS
V_IN
2.2 mF
GND
7 _SD
ERROR ⁸
2 _VIN
6 _CNOISE
V_OUT ^{1, 4}
SET ⁵
3 _GND
Si91821
Optional
V_OUT
2.2 mF
Figure 1. Fixed Output
V_IN
2.2 mF
GND
7 _SD
2 _VIN
6 _CNOISE
3 _GND
ERROR ⁸
V_OUT ^{1, 4}
SET ⁵
Si91821
Figure 2.. Adjustable Output
V_OUT
2.2 mF
ON/OFF
V_IN
2.2 mF
GND
Document Number: 71614
S-51147–Rev. E, 20-Jun-05
0.033 mF
7 _SD
2 _VIN
6 _CNOISE
3 _GND
ERROR ⁸
V_OUT ^{1, 4}
SET ⁵
1 MW
POWER_GOOD
V_OUT
2.2 mF
Si91821
Figure 3. Fixed Output, Low Noise, Full Features Application
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