A 16b 250MS/s IF-sampling pipelined A/D converter with background calibration

Wireless communication applications have driven the development of high-resolution A/D converters (ADCs) with high sample rates, good AC performance and IF sampling capability to enable wider cellular coverage, more carriers, and to simplify the system design. We describe a 16b ADC with a sample rate up to 250MS/s that employs background calibration of the residue amplifier (RA) gain errors. The ADC has an integrated input buffer and is fabricated on a 0.18µm BiCMOS process. When the input buffer is bypassed, the SNR is 77.5dB and the SFDR is 90dB at 10MHz input frequency. With the input buffer, the SNR is 76dB and the SFDR is 95dB. The ADC consumes 850mW from a 1.8V supply, and the input buffer consumes 150mW from a 3V supply. The input span is 2.6Vp-p and the jitter is 60fs.