The MAX731 and MAX752 are fixed and adjustable CMOS, step-up, DC-DC switch-mode regulators. The MAX731 accepts a positive input voltage between +2.5V and +5.25V and converts it to a fixed +5V at 200mA, guaranteed over temperature. Typical full-load efficiencies are 82% to 87%. It requires a single inductor value of 22µH to function over the entire range, so no inductor related design is necessary. The MAX752 is an adjustable version that converts a minimum of + 1.8V to any higher voltage up to +15V, at up to 200mA. Typical full-load efficiencies are 85% to 95%. A single 50µH inductor is suitable for the entire range of operating conditions, so no inductor-related design is necessary.
The MAX731/MAX752 use current-mode pulse-width modulation (PWM) controllers to provide precise output regulation and low subharmonic noise. Typical no-load supply current is 2mA. A fixed 170kHz oscillator frequency allows easy filtering of ripple and noise, and provides for small external components.
The MAX731/MAX752 feature cycle-by-cycle current limiting, overcurrent limiting, external shutdown, and programmable soft-start protection.
For fixed + 12V and + 15V step-up regulators, refer to the MAX732/MAX733 data sheet. For lower-power step-up applications, refer to the MAX631/632/633 and MAX654-659 data sheets.
APPLICATIONS
- +5V-Logic Supply in +3V-Logic System
- DC-DC Converter Module Replacement
- Portable Instruments
- Laptop Computers
- Distributed Power Systems
- Cellular Phones
- Battery-Powered Equipment
