Click to expand full text
CAT3647
3-Channel Ultra High
Efficiency LED Driver with
32 Dimming Levels
Description
The CAT3647 is a high efficiencye fractional charge pump that can drive up to three LEDs programmable by a one wire digital interface. The inclusion of a 1.33x fractional charge pump mode increases device efficiency by up to 10% over traditional 1.5x charge pumps with no added external capacitors.
Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of small external ceramic capacitors. The multi−fractional charge pump supports a wide range of input voltages from 2.4 V to 5.5 V.
The EN/DIM logic input functions as a chip enable and a digital dimming interface for setting the current in all the LED channels.