LED drivers increase brightness and efficiency

With higher driving capabilities and smaller footprint, Zetex ZXLD132x LED drivers ensure maximum performance from the latest generations of high-brightness LEDs.

Three devices support output capabilities ranging from 700mA at 15V to 1.5A at 18V, enabling designers to drive lighting applications up to 24W.

By integrating the DC/DC converter, high-side current monitor and NPN switching transistor, the ZXLD1320, ZXLD1321 and ZXLD1322 combine the benefits of low cost and small footprint with high efficiency, reliability and LED brightness. Excellent efficiency is achieved by using a variable on- and off-time control scheme with adjustable peakswitch- current limiting and step-down operation.

An external Adjust input is provided, allowing 90% or 99% dimming using a DC or PWM signal respectively. In addition, a Temperature-adjust input and on-chip LED protection circuitry allow output current to be reduced linearly above a predetermined threshold temperature using an external thermistor. There is also a Power-OK output to communicate faults or a low-battery condition to a host microcontroller.

 

FEATURES >80% typical efficiency Adjustable soft-start 12µA typical standby current High output-current stability Shutdown via external Adjust pin

APPLICATIONS Low-voltage halogen lamp replacement High-power LED flashlight LED back-up lighting General LED lighting Automotive lighting

 

 

 

• Avago Technologies’ ASMT-QxBx LEDs, page 080503

 

Zetex ZXLD132x LED Drivers