We present a 200 MS/s 2x interleaved 14 bit pipelined SAR ADC in 28nm digital CMOS. The ADC uses a new residue amplifier for low noise at low power, and incorporates interleaved channel time-constant calibration. The ADC achieves a peak SNDR of 70.7 dB at 200 MS/s while consuming 2.3 mW from an 0.9 V supply.