3-bit, 8 GSPS flash ADC

Abstract

A 3-bit multi-Gigasamples/sec (Gs/s) flash analog-to-digital converter (ADC) for high-speed data acquisition systems is reported in this paper. Nyquist operation up to 8 Gs/s has been achieved. The quantizer can convert analog input signals beyond fs/2 up to fs at a sampling rate of 5 Gs/s. In addition, the converter can be operated up to 12.7 Gs/s when the input signal is at low frequencies. This ADC is fabricated in an AlInAs-GaInAs HBT process fabricated on InP substrates with an f/sub T/ of 75 GHz and f/sub max/ of 85 GHz.