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