An 80.2 dB DR 23.25 mW/Channel 8-Channel Ultrasound Receiver With a Beamforming Embedded SAR ADC

An 8-channel ultrasound receiver compatible with in-probe electronics for 3-D ultrasound imaging is proposed. It has eight analog front-ends for signal conditioning and a beamforming embedded SAR analog-to-digital converter (ADC) for performing both an 8-to-1 analog summation and its digitization in charge mode. By combining the 30-dB programmable gain of the analog front-ends with the 60-dB signal-to-noise ratio of the ADC, the 8-channel receiver achieves the DR of 80.2 dB. The delay is set in increments of 4.17 ns, up to a maximum of 292 ns. Implemented in a 0.18-μm CMOS process, a prototype occupies an active area of 0.525 mm
²
/channel and draws 23.25 mW/channel at a sampling frequency of 20 MHz.