A Low-Power, 6-bit Time-Interleaved SAR ADC Using OFDM Pilot Tone Calibration

A low-power analog-to-digital converter (ADC) that exploits communication system resources for continuous self-calibration is presented. The proposed converter employs a time-interleaved array of successive approximation register (SAR) ADCs. The inter-channel offset mismatches are adjusted by a calibration loop that utilizes the outputs of the fast Fourier transform (FFT) block of an orthogonal frequency division multiplexing (OFDM) receiver. The 6-bit prototype ADC, fabricated in a 0.18-mum CMOS technology, achieves an SNDR of 35.4 dB with a power consumption of 6.58 mW at 200 MS/s.