RT9901 pdf datasheet (4 Channe

The RT9901 is a complete power-supply solution for digital
still cameras and other hand-held devices. It integrates a
high-efficiency main step-up DC-DC converter, two highefficiency
step-down converters, a charge pump, and
voltage detector. The RT9901 is targeted for applications
that use either two or three AA cells or a single lithiumion
battery.
The main step-up DC-DC converter accepts inputs from
1.5V to 5.5V and build in 2.6A Internal switch. The two
step-down DC-DC converters (CH2, CH3) accept inputs
from 1.5V to 5.5V and regulate a resistor-adjustable output
from 0.8V to 5.5V. Each DC-DC converters have
independent shutdown inputs.
The feature of the charge pump is to deliver few current
to micro-controller when the system operates in the
standby mode. RT9901 include a low battery detector with
0.8V detection voltage. An adjustable operating frequency
(up to 1.4MHZ) is utilized to get optimum size, cost, and
efficiency.
RT9901 is available in VQFN-32L 5x5 package.