A LOW GLITCH 10-BIT 75-MHZ CMOS VIDEO D/A CONVERTER

A low glitch 10-bit 75-MHz CMOS current-output video digital-to-analog converter (DAC) for high-definition television (HDTV) applications is described. In order to achieve monotonicity and low glitch, a special segmented antisymmetric switching sequence and an innovative asymmetrical switching buffer have been used. The video DAC has been fabricated by using 0.8 mu m single-poly double-metal CMOS technology. Experimental results indicated that the conversion rate is above 75 MHz, and nearly 50% of samples have differential and integral linearity errors less than 0.24 LSB and 0.6 LSB, respectively. The glitch has been reduced to be less than 3.9 pV.s and the settling time within +/- 0.1% of the final value is less than 13 ns. The video DAC is operated by a single 5 V power supply and dissipates 170 mW at 75 MHz conversion rate (140 mW in the DAC portion). The chip size of video DAC is 1.75 mm x 1.2 mm (1.75 mm x 0.7 mm for the DAC portion).