CM3702

PRELIMINARY CALIFORNIA MICRO DEVICES CM3702 Micropower Low-Noise Charge-Pump and Linear Regulator Features Low noise regulator with integrated charge pump voltage-booster 5V output with input voltage as low as 2.8V Charge pump can also power external LDO Low noise in 20Hz to 20kHz audio band Up to 200mA continuous output current Low operating and shutdown currents Stable with low-ESR ceramic or tantalum capacitors 10-Lead MSOP and TDFN packages Lead-free finishing Block Diagram Applications 5V analog supply for audio codec in notebook computers, PDAs, MP3 players, etc. 3.3V to 5V conversion in PCMCIA cards, PCI Express Cards, other applications needing 5V Product Description The CM3702 low-noise charge pump LDO regulator is designed to provide accurate and “clean” power to a subsystem, e.g an audio codec, LED driver, or flash memory. The 5V output provides up to 100mA continuous current for input voltages from 2.8V to 5.5V, and up to 200mA for a narrower range. This is accomplished with an integrated charge pump that boosts the input voltage before feeding it to an internal LDO linear regulator. The charge pump is designed to maintain a nominal 0.8V differential between the input and output of the LDO regulator. This allows the LDO regulator to operate with good power supply ripple rejection across the audio band while maintaining good power efficiency. The charge pump works with two external capacitors and operates at 250kHz, well outside the audi...