MAX782

19-0146; Rev 2; 5/94 InfEorvmalautaiotinonInKcliut ded Triple-Output Power-Supply Controller for Notebook Computers MAX782 _______________General Description The MAX782 is a system-engineered power-supply controller for notebook computers or similar battery-powered equipment. It provides two high-performance step-down (buck) pulse-width modulators (PWMs) for +3.3V and +5V, and dual PCMCIA VPP outputs powered by an integral flyback winding controller. Other functions include dual, lowdropout, micropower linear regulators for CMOS/RTC backup, and three precision low-battery-detection comparators. High efficiency (95% at 2A; greater than 80% at loads from 5mA to 3A) is achieved through synchronous rectification and PWM operation at heavy loads, and IdleModeTM operation at light loads. It uses physically small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM architecture that allows for output filter capacitors as small as 30µF per ampere of l...