Video-rate D/A converter using reduced rate sigma-delta modulation

Dagnachew Birru, Engel Roza

Abstract: Full 5-MHz-bandwidth video-signal is converted from digital-to-analog by a novel sigma-delta modulation technique at an equivalent PCM-precision of 8 bits. This new type of signal processing allows the sigma-delta modulator to operate at 54-MHz, which is about a quarter of the rate that would be required in equivalent conventional configurations. Owing to the reduced clock frequency, the power dissipation of the D/A converter is as low as 15 mW.