PT4302 Datasheet | Powtech

DESCRIPTION The PT4302 is a 2-channel 1×/1.5× auto-adjust charge pump white LED driver with LED fault detection. The auto-adjust charge pump achieves high efficiency for an Li-lion battery supply. LED fault detection feature allows the PT4302 to be self-adjusted to normal operation if an open or short occurs. The PT4302 needs few external ponents, which makes it an ideal choice for portable applications where a smaller board space is critical. The LED current is programmable from 3m A to 25m A in a 3m A step by applying digital codes at the EN/SET pin. A built-in soft-start circuit prevents a high inrush current from being drawn from the supply source during power on and 1×/1.5× mode switching. The thermal shutdown and current limiter prevents the PT4302 from being damaged by short to ground or overload conditions. The ultra small shut-down current of less than 1µA significantly prolongs the battery life. The PT4302 is available in small MSOP-10 and QFN-10 packages. FEATURES z 2.7V-5.5V input range z 1x/1.5x auto-adjust charge pump z LED fault detection z Programmable 8 level LED currents from 3m A to 25m A z < ±2% LED maximum current mismatch between channels z Less than 1µA shut down current z Built-in soft-start and mode soft-switching z Miniature MSOP-10 and QFN-10 package APPLICATIONS z Cell phones z PDAs z Digital cameras z Small LCD displays z Programmable current sink PACKAGES Vin C1+ Vin C1+ C2- Vout C2- Vout C1- C2+ C1- C2+ Gnd led2 Gnd led2 En/Set led1 En/Set led1 MSOP-10 Top View QFN-10 Top View TYPICAL APPLICATION 3V to 5.5V Cin Vin 1u F C1+ C1 1u F C1- C2+ C2 1u F C2- En/Set Vout All capacitors are ceramic capacitors D1 led1 Gnd...