A Single-Chip 64-Channel Ultrasound RX-Beamformer Including Analog Front-End and an LUT for Non-Uniform ADC-Sample-Clock Generation

作者：Kim Yoon Jee; Cho Sung Eun; Um Ji Yong; Chae Min Kyun; Bang Jihoon; Song Jongkeun; Jeon Taeho; Kim Byungsub; Sim Jae Yoon; Park Hong June^*

来源：IEEE Transactions on Biomedical Circuits and Systems, 2017, 11(1): 87-97.

DOI：10.1109/TBCAS.2016.2571739

• ADC sample clock generator
• digital beam-former
• non-uniform sampling
• RX beamformer
• ultrasound

A 64-channel RX digital beamformer was implemented in a single chip for 3-D ultrasound medical imaging using 2-D phased-array transducers. The RX beamformer chip includes 64 analog front-end branches including 64 non-uniform sampling ADCs, a FIFO/Adder, and an on-chip look-up table (LUT). The LUT stores the information on the rising edge timing of the non-uniform ADC sampling clocks. To include the LUT inside the beamformer chip, the LUT size was reduced by around 240 times by approximating an ADC-sample-time profile w.r.t. focal points (FP) along a scanline (SL) for a channel into a piece-wise linear form. The maximum error between the approximated and accurate sample times of ADC is eight times the sample time resolution (Ts) that is 1/32 of the ultrasound signal period in this work. The non-uniform sampling reduces the FIFO size required for digital beamforming by around 20 times. By applying a 9-dot image from Field-II program and 2-D ultrasound phantom images to the fabricated RX beamformer chip, the original images were successfully reconstructed from the measured output. The chip in a 0.13-um CMOS occupies 30.25 mm(2) and consumes 605 mW.

• 出版日期2017-2