- Step-up synchronous-rectified DC-DC converter (SU). The MAX8857AETL+ 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.
Feature
- 95% Efficient Synchronous-Rectified DC-DC Converters
- 90% Efficient Boost-Buck Operation
- Up to 85% Efficient, High-Voltage DC-DC Converters
- Inverter Operates Directly from 2 AA Batteries
- Internal Compensation on All Channels
- True Shutdown? on All Step-Up Converters
- Overload Protection
- Startup into Short Protection
- Soft-Start for Controlled Startup Current
- 100% Duty Cycle on Step-Down Converters
- Regulated Current Output for Up to 6 White LEDs
- PWM Dimming of WLED Current
- Adjustable LED Overvoltage Protection Up to 27V
- Transformerless Inverting Converter for CCD
- 2MHz ±2.5% Switching Frequency
- 1μA Shutdown Supply Current
- CCD Voltage Sequencing
- All Internal Power MOSFETs
- SDOK Power-OK Indicator
Applications
- DSCs and DVCs
- PDAs and Portable Media Players