A 16-bit 250-MS/s IF Sampling Pipelined ADC With Background Calibration

This paper describes a 16-bit 250 MS/s ADC fabricated on a 0.18 BiCMOS process. The ADC has an integrated input buffer with a new linearization technique that improves its distortion by 5-10 dB and lowers its power consumption by 70% relative to the state of the art. It demonstrates a new background calibration technique to correct the residue amplifier (RA) gain errors and lower its power consumption. This summing node sampling (SNS) calibration technique is based on sampling the summing-node voltage of the residue amplifier and using it with the corresponding residue to estimate the amplifier open loop gain. The ADC achieves an SNDR of 76.5 dB and consumes 850 mW from a 1.8 V supply, while the input buffer consumes 150 mW from a 3 V supply. Up to 125 MS/s, the SFDR is greater than 100 dB for input frequencies up to 100 MHz and 90 dB up to 300 MHz input frequency. At 250 MS/s, the SFDR is greater than 95 dB up to 100MHz and 85 dB up to 300 MHz.