LP3981 Datasheet, PDF (1/11 Pages) National Semiconductor (TI) – Micropower, 300mA Ultra Low-Dropout CMOS Voltage

March 2003
LP3981
Micropower, 300mA Ultra Low-Dropout CMOS Voltage
Regulator
General Description
The LP3981’s performance is optimized for battery powered
systems to deliver ultra low noise, extremely low dropout
voltage and low quiescent current. Regulator ground current
increases only slightly in dropout, further prolonging the
battery life.
Power supply rejection is better than 60 dB at low frequen-
cies. This high power supply rejection is maintained down to
lower input voltage levels common to battery operated cir-
cuits.
The device is ideal for mobile phone and similar battery
powered wireless applications. It provides up to 300 mA,
from a 2.5V to 6V input, consuming less than 1µA in disable
mode.
The LP3981 is available in MSOP-8 package. For LP3981 in
LLP-6 package, contact NSC sales offices. Performance is
specified for −40˚C to +125˚C temperature range. The de-
vice available in the following output voltages; 2.5V, 2.7V,
2.8V, 2.83V, 3.0V, 3.03V and 3.3V as standard. Other output
options can be made available, please contact your local
NSC sales office.
Key Specifications
n 2.5 to 6.0V input range
n 300mA guaranteed output
n 60dB PSRR at 1kHz
n ≤1µA quiescent current when shut down
n Fast Turn-On time: 120 µs (typ.) with C_BYPASS = 0.01uF
n 132mV typ dropout with 300mA load
n 35µVrms output noise over 10Hz to 100kHz
n −40 to +125˚C junction temperature range for operation
n 2.5V, 2.7V, 2.8V, 2.83V, 3.0V, 3.03V, and 3.3V outputs
standard
Features
n Small, space saving MSOP-8
n Low Thermal Resistance in LLP-6 package gives
excellent power capability
n Logic controlled enable
n Stable with ceramic and high quality tantalum capacitors
n Fast turn-on
n Thermal shutdown and short-circuit current limit
Applications
n CDMA cellular handsets
n Wideband CDMA cellular handsets
n GSM cellular handsets
n Portable information appliances
n Tiny 3.3V ± 5% to 2.5V, 300mA converter
Typical Application Circuit
Note: Pin Numbers in parenthesis indicate LLP-6 package.
20020302
© 2003 National Semiconductor Corporation DS200203
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