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. This ADC incorporates a single sample-and-hold amplifier which employs a precharged circuit configuration to mitigate performance requirements for its opamp. Digital background calibration is applied to maintain the conversion linearity of each A/D 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.