A CMOS 15-bit 125-MS/s time-interleaved ADC with digital background. calibration

Abstract

A 15-bit 125-MS/s two-channel time-interleaved pipelined ADC is fabricated in a 0.18 mu m CMOS technology, and achieves 91.9 dB SFDR, 69.9 dB SNDR for a 9.99 MHz input. The ADC uses a single sample-and-hold amplifier which employs a precharging circuit technique to mitigate the performance requirements for its opamp. Digital background calibration is applied to maintain the conversion linearity of each AID channel and also correct both gain and offset mismatches between the two channels. Excluding I/O buffers, the chip occupies an area of 4.3 x 4.3 mm(2) and dissipates 909 mW from a 1.8 V supply.