A 12-bit 350[Formula: see text]MS/s ADC with 75[Formula: see text]dB SFDR fabricated in 0.18[Formula: see text][Formula: see text]m SiGe BiCMOS process is presented. To improve the power efficiency, the ADC employs a novel residue amplifier (RA) by exploiting the hetero-junction bipolar transistor (HBT). We also propose a fast comparator to save time for the residue settling of pipeline stages. A fully integrated reference buffer with “negative bootstrap power” (NBP) is proposed to improve both high power supply rejection ratio (PSRR) and ground supply rejection ratio (GSRR). A bandgap reference (BGR) with ultra-low leakage current start-up loop is also presented. The measured results show that with Nyquist input, the SFDR achieves 75[Formula: see text]dB and 63[Formula: see text]dB SNDR up to 350[Formula: see text]MS/s and consumes 180[Formula: see text]mW (only ADC core) with 580[Formula: see text]fj/cov Waldon FOM.