Evaluation Board For High Efficiency LED Driver

The KIT34844AEPEVBE Evaluation board supports the 34844/A, which is a high efficiency, LED driver for use in backlighting LCD displays from 10" to 20"+. Operating from supplies of 7.0 to 28V, the MC34844/A is capable of driving up to 160 LEDs in 10 parallel strings. Current in the 10 strings is matched to within ±2%, and can be programmed via the I2C/SM Bus interface. The 34844/A also includes a Pulse Width Monitor (PWM) generator for LED dimming. The LEDs can be dimmed to one of 256 levels, programmed through the I2C/SM Bus interface. Up to 65,000:1 (256:1 PWM, 256:1 Current DAC) dimming ratio. The integrated boost converter generates the minimum output voltage required to keep all LEDs illuminated with the selected current, providing the highest efficiency possible.

Input voltage of 7.0 to 28V

2.5A integrated boost FET

Up to 50 mA on the 34844 LED current per channel

Up to 80 mA on the 34844A LED current per channel

90% efficiency (DC:DC)

I2C/SM Bus interface

10 channel current mirror with ±2% current matching

Boost output voltage up to 60V, with Dynamic Headroom Control (DHC)

PWM frequency programmable or synchronizable from 100 to 25,000 Hz for the 34844

PWM frequency programmable or synchronizable from 110 to 27,000 Hz for the 34844A

32-Ld 5x5x1.0mm TQFN Package