High-Efficiency, Triple-Output System Power Supply Controller for Notebook Computers

The ISL62392C controller generates supply voltage for battery-powered systems. It includes two pulse-width modulation (PWM) controllers, adjustable from 0. 6V to 5. 5V, and a linear regulator (LDO3) that generates a fixed 3. 3V and can deliver up to 100mA. The ISL62392C includes on-board power-up sequencing, a power-good (PGOOD) output, digital soft-start, and internal soft-stop output discharge that prevents negative voltages on shutdown. The patented R3 PWM control scheme provides a low jitter system with fast response to load transients. Light-load efficiency is improved with period-stretching discontinuous conduction mode (DCM) operation. To eliminate noise in audio frequency applications, an ultrasonic DCM mode is included, which limits the minimum switching frequency to 28kHz. The ISL62391, ISL62391C and ISL62392, ISL62392C are identical except for how their overvoltage protection is handled. The ISL62391C utilizes a tri-state overvoltage scheme, whereas the ISL62392C employs a soft-crowbar method. The ISL62392C is available in a 28 Ld 4x4 TQFN package and operates over the extended temperature range (-40°C to +100°C).