LP3999 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Low Noise 150mA Voltage Regulator for RF/Analog Applications

November 2005
LP3999
Low Noise 150mA Voltage Regulator for RF/Analog
Applications
General Description
The LP3999 regulator is designed to meet the requirements
of portable wireless battery-powered applications and will
provide an accurate output voltage with low noise and low
quiescent current. Ideally suited for powering RF/Analog
devices this device will also be used to meet more general
circuit requirements.
For battery powered applications the low dropout and low
ground current provided by the device allows the lifetime of
the battery to be maximized.The inclusion of an Enable(dis-
able) control can be used by the system to further extend the
battery lifetime by reducing the power consumption to virtu-
ally zero. Should the application require a device with an
active disable function please refer to device LP3995.
The LP3999 also features internal protection against short-
circuit currents and over-temperature conditions.
The LP3999 is designed to be stable with small 1.0 µF
ceramic capacitors. The small outline of the LP3999 micro
SMD package with the required ceramic capacitors can
realize a system application within minimal board area.
Performance is specified for a −40˚C to +125˚C temperature
range.
The device is available in micro SMD package. For other
package options contact your local NSC sales office.
The device is available in fixed output voltages in the ranges
of 1.5V to 3.3V. For availability, please contact your local
NSC sales office.
Key Specifications
n 2.5V to 6.0V Input Range
n Accurate Output Voltage; ±75mV / 2%
n 60 mV Typical Dropout with 150 mA Load. V_out > 2.5V
n Virtually Zero Quiescent Current when Disabled
n 10 µVrms output noise over 10Hz to 100kHz
n Stable with a 1 µF Output Capacitor
n Guaranteed 150 mA Output Current
n Fast Turn-on Time; 140 µs (Typ.)
Features
n 5 pin micro SMD Package
n Stable with Ceramic Capacitor
n Logic Controlled Enable
n Fast Turn-on
n Thermal-overload and short-circuit protection
n −40 to +125˚C junction temperature range for operation
Applications
n GSM Portable Phones
n CDMA Cellular Handsets
n Wideband CDMA Cellular Handsets
n Bluetooth Devices
n Portable Information Appliances
n Handheld MP3 Devices
Typical Application Circuit
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