General description
The MAX782 is a system-engineered power controller for notebook computers or similar battery-operated devices. It provides two high performance step-down (buck) pulse width modulators (PWM) for +3.3 V and +5 V, VPP output and dual PCMCIA powered by an integral flyback winding controller. Other features include dual, lowdropout, micropower CMOS/RTC backup linear regulators, and triple precision low battery detection comparators. High efficiency (95% at 2A; load greater than 80% from 5mA to 3A) is achieved through synchronous rectification at heavy loads and PWM operation and idle ModeTM operation at light loads. It uses small physical components, and due to the high operating frequency (300kHz/200kHz) and a new current-mode PWM architecture, the output filter capacitors allow as small as 30µF per amp load. Line and load transient response is excellent, with a high 60kHz unity gain crossover frequency will allow output transients to be corrected for 4,5 clock cycles. Low system cost is achieved through a high level of integration and low use cost, external N-channel MOSFETs. This integral-winding flyback controller provides a low-cost, +15 V high-side output even in the absence of regulation for a main output load. Other features include low noise, fixed frequency PWM operation for moderate to heavy loads and a synchronizable oscillator for noise sensitive applications such as electromagnetic pen systems and communication computers. The MAX782 is available in a monolithic BiCMOS fine-pitch, SSOP packaged surface mount package.

Computer Pen Input System Using Notebook Computer Portable Data Terminal Communication