General Description
The MAX768 low-noise, dual-output, regulated charge pump provides a negative output for biasing GaAsFET power amplifiers, and a positive output for powering voltage-controlled oscillators (VCOs) in wireless handsets. The outputs can also be used to power LCDs. Output ripple is less than 2mVp-p. The MAX768 is intended for use in low-voltage systems where a simple charge-pump inverter is inadequate, or where the VCO needs more range to improve its signal-to-noise ratio. The input range is 2.5V to 5.5V, enabling direct power from 1Li+ and 3-cell NiMH/NiCd batteries.
Features
⦠Dual Positive/Negative Regulated Outputs: ±5VOUT from 3VIN
⦠Output-Ready Indicator to Protect GaAsFET PAs
⦠2.5V to 5.5V Input Voltage Range
⦠Low-Noise Output Ripple: < 2mVp-p
⦠Synchronizable Switching Frequency
⦠Uses Only Small, Low-Cost Capacitors
⦠0.1µA Independent Shutdown Controls
⦠Adjustable Output Voltages
⦠Small 16-Pin QSOP Package
Applications
GaAsFET Power Amp Bias
Voltage-Controlled Oscillator (VCO) Supply
Tuner Diode Power Supply
Positive and Negative LCD Supply
Cellular Phone
PCS and Cordless Phone
Wireless Handsets
Wireless Handheld Computers
Wireless PCMCIA Cards
Modems
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