The RT9903 is a complete power-supply solution for digital
still cameras and other hand-held devices. It integrates a
high-efficiency fours step-up DC-DC converters and a
charge pump.
The two Step-up DC-DC converters (CH1,CH2) accept
inputs from 1.5V to 5.5V and regulate a resistoradjustable
output up to 17V. One Step-up DC-DC
converter (CH3) can be regarded as white LED Driver,
which reference voltage is 0.2V and have OVP function.
One step-up DC-DC converter (CH4) regulate a resistoradjustable
output up 5V. An adjustable operating
frequency (up to 1.4MHz) is utilized to get optimum size,
cost, and efficiency.
The feature of the charge pump (CH5) is to deliver few
current to CCD negative voltage.
RT9903 is available in VQFN-24L 4x4 package. Each
DC-DC converters have independent shutdown inputs.