The MAX8857A PMIC provides a complete power-supply solution for digital still cameras (DSCs) and digital video cameras (DVCs). The MAX8857A improves performance, component count, and board space utilization compared to currently available solutions for 2 AA cell and dual-battery designs. On-chip power MOSFETs provide up to 95% efficiency for critical power supplies. The CCD inverter can operate directly from 2 AA/NiMH batteries without the use of any additional external components.
- Step-up synchronous-rectified DC-DC converter (SU). The MAX8857A is bootstrapped from VSU.
- MAIN synchronous-rectified step-up DC-DC converter (M) with active discharge for DSP I/O supply voltage.
- SDZ synchronous-rectified step-down DC-DC converter (Z) for DSP DDR supply voltage.
- Low-voltage (down to 1V) synchronous-rectified step-down DC-DC converter (SD) for DSP core supply voltage.
- Step-up DC-DC converter with current regulation and PWM dimming control (LEDBST) for up to 6 series white LEDs (WLED).
- High-voltage step-up DC-DC converter (CCDBST) for CCD imagers or positive LCD bias supplies.
- Transformerless inverting DC-DC converter (CCDINV) for CCD imagers or negative LCD bias supplies. This converter can connect directly to 2 AA batteries.
The MAX8857A has an independent/simultaneous power-on sequence of the CCDBST and CCDINV converters. For a preset power-on sequence of CCDBST before CCDINV, contact the factory.
The MAX8857A is available in a 5mm x 5mm, 40-pin thin QFN package and operates over the -40°C to +85°C extended temperature range.
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