An 8-bit 22-MHz recycling two-step ASIC ADC with integrating sample and hold

A recycling two-step architecture with a very low input current comparator is presented to implement an 8-b analog-to-digital converter (ADC) with an integrating sample and hold circuit that yields a 22-Msps conversion rate with a 10-MHz input. This two-step recycling architecture makes use of a novel switch circuit design reducing the number of components required for the complete ADC. The ADC is realized using 900 transistors on two-metal, f/sub T/=8.5 GHz, npn bipolar junction transistor (BJT) application-specific integrated circuits.<<ETX>>