LED Drivers Fit In 3 mm x 4 mm DFNs

A family of three LED drivers, the ZXLD132X series inductive dc/dc converters drive single or multiple LEDs with currents from 700 mA to 1.5 A, in buck, boost, and buck/boost configurations. The devices combine a dc/dc converter, current monitor, thermal control circuitry, and a 2A NPN switching transistor into DFN packages measuring 3 mm x 4 mm. They also employ a variable on/off time-control scheme with an adjustable peak switch current limit. Both LED current and peak inductor current can be set independently and a feedback control circuit ensures a typical LED current stability of ±3% throughout battery life and across a -40ºC to 125ºC operating temperature range. The ZXLD1320 buck mode driver delivers up to 1.5A continuous LED current for an input voltage range of 4V to 18V and provides a maximum power of 24W. The ZXLD1321 boost mode driver produces 1A for an input voltage of 1V to 12V and the ZXLD1322 buck/boost mode driver produces 700 mA for an input voltage of 2.5V to 15V. Prices are in the range of $1.35 each/1,000 quantities. ZETEX INC., Hauppauge, NY. (631) 360-2222.