High-Efficiency, Triple-Output System Power Supply Controller for Notebook Computers
The ISL62391, ISL62392 controller generates supply voltages
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 ISL62391, ISL62392 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 and ISL62392 are identical except for how
their overvoltage protection is handled. The ISL62391
utilizes a tri-state overvoltage scheme, whereas the
ISL62392 employs a soft-crowbar method.
The ISL62391, ISL62392 is available in a 28 Ld 4x4 TQFN
package and operates over the extended temperature range
(-10°C to +100°C).