SI91871_05 Datasheet, PDF (1/10 Pages) Vishay Siliconix – 300-mA Ultra Low-Noise LDO Regulator With Discharge Option

Si91871
Vishay Siliconix
300-mA Ultra Low-Noise LDO Regulator
With Discharge Option
FEATURES
D Ultra Low Dropout—300 mV at 300-mA Load
D Ultra Low Noise—30 mV_RMS (10-Hz to 100-kHz)
D Shutdown Control
D 130-mA Ground Current at 300-mA Load
D 1.5% Guaranteed Output Voltage Accuracy
D 400-mA Peak Output Current Capability
D Uses Low ESR Ceramic Capacitors
D Fast Start-Up (50 ms)
D Fast Line and Load Transient Response (v 30 ms)
D 1-mA Maximum Shutdown Current
D Output Current Limit
D Reverse Battery Protection
D Built-in Short Circuit and Thermal Protection
Available
DESCRIPTION
The Si91871 is a 300-mA CMOS LDO (low dropout) voltage
regulator. It is the perfect choice for low voltage, low power
applications. An ultra low ground current makes this part
attractive for battery operated power systems. The Si91871
also offers ultra low dropout voltage to prolong battery life in
portable electronics. Systems requiring a quiet voltage
source, such as RF applications, will benefit from the
Si91871’s ultra low output noise. An external noise bypass
capacitor connected to the device’s BP pin can further reduce
the noise level. The Si91871 is designed to maintain regulation
while delivering 400-mA peak current, making it ideal for
systems that have a high surge current upon turn-on.
For better transient response and regulation, an active
D Output, Auto-Discharge In Shutdown Mode
D Fixed 1.2, 1.8, 2.5, 2.6, 2.8, 3.0, 3.3, 5.0-V Output
Voltage Options
D MLP33-5 PowerPAKr Package
APPLICATIONS
D Cellular Phones, Wireless Handsets
D Noise-Sensitive Electronic Systems, Laptop and
Palmtop Computers
D PDAs
D Pagers
D Digital Cameras
D MP3 Player
D Wireless Modem
pull-down circuit is built into the Si91871 to clamp the output
voltage when it rises beyond normal regulation. The Si91871
automatically discharges the output voltage by connecting the
output to ground through a 100-W n-channel MOSFET when
the device is put in shutdown mode.
The Si91871 features reverse battery protection to limit
reverse current flow to approximately 1-mA in the event
reversed battery is applied at the input, thus preventing
damage to the IC.
The Si91871 is available in both the standard and
lead (Pb)-free 5-pin MLP33 PowerPAK packages and is
specified to operate over the industrial temperature range of
−40_C to 85_.
TYPICAL APPLICATION CIRCUIT
V_IN
2.2 mF
SD
Si91871
V_IN
V_OUT
SD
GND
BP
MLP33-5
V_OUT
2.2 mF
10 nF
Document Number: 72012
S-51147—Rev. F, 20-Jun-05
www.vishay.com
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