CAT3637

CAT3637 6-Channel Programmable High Efficiency LED Driver Description The CAT3637 is a high efficiency fractional charge pump that can drive up to six LEDs programmable by a 1−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 2.5 V to 5.5 V. The EN/SET logic input functions as a chip enable and a digital programming interface for setting the current in the LED channels. The 1−wire pulse−programming interface supports 15 linear steps from zero current to 30 mA full−brightness in 2 mA steps. The device is available in a tiny 16−pad TQFN 3 x 3 mm package with a maximum height of 0.8 mm. ON Semiconductor’s 1.33x, charge pump switching architecture is patented. Features High Efficiency 1.33x Charge Pump Charge Pump: 1x, 1.33x, 1.5x, 2x Drives 6 LEDs Between 30 mA and 0 mA Each 1−wire EZDimt Interface with 2 mA Step Power Efficiency up to 92% Low Noise Input Ripple in All Modes “Zero” Current Shutdown Mode Soft Start and Current Limiting Short Circuit Protection Thermal Shutdown Protection Tiny 3 mm x 3 mm, 16−pad TQFN Package These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant Applicati...