ULTRA-HIGH-SPEED 8-BIT A/D CONVERTER.

A monolithic type ultra-high-speed 8-bit parallel A/D converter has been developed by using bipolar VLSI technology. To achieve ultra-high-speed and high-accuracy conversion, new bipolar transistors and new circuits are needed. High-speed, high-accuracy bipolar transistors have been developed by using selective oxidation self-aligning and double ion implantation technologies. The distribution of the base-emitter offsets of the transistor pairs is lower than 250 mu v and the maximum value of f//T is 3. 5 GHz. Three-stage comparators with small clock-noise and stable high-speed operation, new clock-drive circuits to reduce ringing, and glitch-suppression circuits have been developed. The bipolar VLSI chip contains 24,000 components with the layout developed by considering the signal propagation delay. A snr of 45 db at a 30 MHz input frequency and a maximum conversion rate of 100 MSPS have been obtained. This A/D converter (AN8108) is applied to high-definition TV systems and digital oscilloscopes.