LP3986 Datasheet, PDF (1/13 Pages) National Semiconductor (TI) – Dual Micropower 150 mA Ultra Low-Dropout CMOS Voltage Regulators in micro SMD Package

May 2003
LP3986
Dual Micropower 150 mA Ultra Low-Dropout CMOS
Voltage Regulators in micro SMD Package
General Description
The LP3986 is a 150 mA dual low dropout regulator de-
signed for portable and wireless applications with demand-
ing performance and board space requirements.
The LP3986 is stable with a small 1 µF ±30% ceramic output
capacitor requiring smallest possible board space.
The LP3986’s performance is optimized for battery powered
systems to deliver ultra low noise, extremely low dropout
voltage and low quiescent current independent of load cur-
rent. Regulator ground current increases very slightly in
dropout, further prolonging the battery life. Optional external
bypass capacitor reduces the output noise further without
slowing down the load transient response. Fast start-up time
is achieved by utilizing a speed-up circuit that actively pre-
charges the bypass capacitor. Power supply rejection is
better than 60 dB at low frequencies and 55 dB at 10 kHz.
High power supply rejection is maintained at low input volt-
age levels common to battery operated circuits.
The LP3986 is available in a micro SMD package. Perfor-
mance is specified for a −40˚C to +125˚C temperature
range. For single LDO applications, please refer to the
LP3985 datasheet.
Features
n Miniature 8-I/O micro SMD package
n Stable with 1µF ceramic and high quality tantalum
output capacitors
n Fast turn-on
n Two independent regulators
n Logic controlled enable
n Over current and thermal protection
Key Specifications
n Guaranteed 150 mA output current per regulator
n 1nA typical quiescent current when both regulators in
shutdown mode
n 60 mV typical dropout voltage at 150 mA output current
n 115 µA typical ground current
n 40 µV typical output noise
n 200 µs fast turn-on circuit
n −40˚C to +125˚C junction temperature
Applications
n CDMA cellular handsets
n GSM cellular handsets
n Portable information appliances
n Portable battery applications
Typical Application Circuit
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