Intersil's Backlight LED Drivers Improve Energy Efficiency and Increase Battery Life of Tablets, Mobile Devices
With a minimum input voltage of just 2.4V, and quiescent current of only 0.8mA, the new ISL97692/3/4A series of LED drivers makes the most of the limited capacity of Li-Ion batteries in portable devices. The ISL97692 incorporates four channels with up to 40mA each, while the ISL97693 and ISL97694A provide six channels with up to 30mA each. All the drivers feature output current phase shifting which maximizes efficiency during PWM dimming and increases the effective output current frequency to eliminate audible noise. Additionally, when operating from a single cell Li-Ion battery, the drivers do not require any input voltage other than the battery, reducing board size and component count.
Features and Specifications
- 90% efficient with 3.7V input, driving 6-parallel, 5-series LED configuration at 20mA/LED
- 0.8mA supply current and phase shifted PWM dimming improve energy efficiency and extend battery life
- 2.4V minimum input voltage allows operation from a single cell Li ion battery and reduces component count
- Wide dimming range down to 0.025% duty cycle at 5kHz frequency
- Phase shifting multiplies the effective dimming frequency by the number of channels, permitting ultrasonic PWM dimming with 10-bit dimming resolution