AN 8-B ADC WITH OVER-NYQUIST INPUT AT 300-MS/S CONVERSION RATE

This paper describes an 8-b flash A/D converter (ADC) LSI for high-speed data acquisition systems such as digital oscilloscopes and wave digitizers. This converter can convert analog input signals over the Nyquist frequency (up to 200 MHz) at a conversion rate of 300 megasamples per second (Ms/s) without glitch errors. In addition, it can be operated at up to 440 Ms/s when input frequency is as low as 100 kHz. This ADC is fabricated by a 2.5-mu-m, 10-GHz f(T), Si bipolar technology, called the advanced sidewall base contact structure (advanced SICOS) technology. For high-performance glitch error suppression, a new inhibitory circuit and a comparator design with an inner clock buffer are developed. Both techniques require few hardware additions.