The MAX782CBX 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, low dropout, 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 Idle- ModeTM 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 load. Line- and load-transient response are terrific, with a high 60kHz unity-gain crossover frequency allowing output transients to be corrected within four or five clock cycles. Low system cost is achieved through a high level of integration and the use of low-cost, external N-channel MOSFETs. The integral flyback winding controller provides a low-cost, +15V high-side output that regulates even in the absence of a load on the main output. Other features include low-noise, fixed-frequency PWM operation at moderate to heavy loads and a synchronizable oscillator for noise-sensitive applications such as electromagnetic pen-based systems and communicating computers. The MAX782CBX is a monolithic BiCMOS IC available in a fine-pitch, SSOP surface-mount package.
Dual PWM Buck Controllers (+3.3V and +5V)
Dual PCMCIA VPP Outputs (0V/5V/12V)
Three Precision Comparators or Level Translators
420µA Quiescent Current; 70µA in Standby (linear regulators alive)
5.5V to 30V Input Range
Portable Data Terminals
Datasheet Available:Maxim MAX782CBX
SSOP 36 package. Manufactured by Maxim.