LED drivers with PWM dimming for LCD backlight

The device drives strings of either RGB LEDS or multiple strings of white LEDs and boost or SEPIC converters in either continuous-conduction mode (CCM) or discontinuous-conduction mode (DCM).

The HV9989 is powered by a built-in 40V linear regulator.

It features independent short- and open-circuit protection for each channel and three 1MHz transconductance amplifiers with tri-state outputs to close feedback loops and accurately control the LED current, noted Supertex. It is powered by a built-in 40V linear regulator, added the company.

"HV9989 can operate with very high dimming frequency and deliver an over 10,000:1 dimming ratio because of its patented PWM dimming method," said Stephen Lin, VP of marketing at Supertex. "The IC combines excellent line and load regulation in a multichannel driver IC to reduce board space and system cost in LCD backlighting applications like flat screen TVs and monitors."

The HV9989 is available in a 40-lead QFN package (HV9989K6-G) at $3.78 for 1K quantities. Samples are available from stock. Lead-time for production quantities is 4-6 weeks ARO.