DESCRIPTION
The LTC®1682/LTC1682-3.3/LTC1682-5 are doubler charge pumps with an internal low noise, low dropout (LDO) linear regulator. These parts are designed to provide a low noise boosted supply voltage for powering noise sensitive devices such as high frequency VCOs in wireless applications.

FEATURES
■ Low Output Noise: 60µVRMS (100kHz BW)
■ Adjustable or Fixed Boosted Output
■ Adjustable Output Voltage Range: 2.5V to 5.5V
■ Fixed Output Voltages: 3.3V, 5V
■ Wide Input Voltage Range: 1.8V to 4.4V
■ Uses Small Ceramic Capacitors
■ No Inductors Required
■ Output Current up to 50mA
■ 550kHz Switching Frequency
■ Low Operating Current: 150µA
■ Low Shutdown Current: 1µA
■ Internal Thermal Shutdown and Current Limiting
■ Available in 8-Pin MSOP and SO Packages

APPLICATIONS
■ VCO Power Supplies in Cellular Phones
■ 2-Way Pagers
■ Wireless PCMCIA Cards
■ Portable Medical Instruments
■ Low Power Data Acquisition
■ Remote Transmitters