A 5 V, 6-b, 80 Ms/s BiCMOS flash ADC

A 5 V single supply, 6-bit flash A/D converter (ADC) has been developed that supports sampling rates of up to 80 Ms/s. The converter is optimized to operate in undersampling applications where the ADC has to deliver greater than 5.2 Effective Number Of Bits (ENOB's) with input frequencies well beyond Nyquist. Excellent dynamic linearity performance has been achieved with input frequencies up to 75 MHz and a gain flatness of better than 0.1 dB is obtained over the input signal spectrum of 50 MHz-95 MHz. This ADC is fabricated on a 1.0 μm advanced BiCMOS process that features trench-isolated bipolar devices with an f_t of 10 GHz