LED driver ICs optimise images in backlit LCD TVs

With the AS3695A - a 16-channel white LED driver for direct lighting - and the AS3695C - a 16-channel white LED controller for edge lighting - austriamicrosystems extends its portfolio of LED BLU (backlight unit) drivers and controllers Both ICs feature power management and are said to offer the best available accuracy.

Driver accuracy of +/-0.5 per cent guarantees exact brightness and colour matching, and channel-to-channel current matching is +/-0.2 per cent - resulting in high lighting contrast ratios for the best possible picture quality and 3D effects.

In addition, the high-precision AS3695A and AS3695C include novel power feedback regulation for controlling external power supplies for high system efficiency and reduced power in LED backlit LCD TVs.

The devices are programmable via a SPI (serial peripheral interface) port and provide built-in safety features, including thermal shutdown and open and short LED detection.

Other features include linear current setting using a 10-bit DAC, output slew rate programmability, H-Sync and V-Sync inputs to synchronise with a TV, direct PWM mode, undervoltage auto-turnoff, overvoltage auto-turnoff, temperature shutdown and fault interrupt output.