A CMOS triple 100-Mbit/s video D/A converter with shift register and color map

A 100-Mb/s CMOS video digital-to-analog converter (VDAC) chip is described. The VDAC provides all output functions for a four-plane color video subsystem. Included in this chip are: direct drivers for 75-/spl Omega/ cables; three 100-MHz 4-bit DACs; a color-map memory; video shift registers; cursor logic and a processor interference. The design approaches for both the analog and digital circuitry are discussed. The bench and automatic testing of this high-speed, high-pin-count, combined analog/digital chip are presented.