An Area-Power-Efficient AFE with NS-SAR ADC For High-Frequency Ultrasound Applications

Abstract

This paper presents an integrated ultrasound analog front-end (AFE) featuring wide bandwidth and high area-power-efficiency, which is suitable for high-frequency ultrasound applications. The AFE includes an LNA. VGA, and NS-SAR ADC. The LNA and VGA adopt energy-efficient architecture and achieve more than 100MHz bandwidth. The ADC utilizes a bandpass noise-shaping SAR scheme, improving SNR within the bandwidth of a PMUT transducer. The prototype is fabricated in a 0.18μm HV process, which can further be integrated with HV TX components. The test and simulation results show that this AFE has a channel SNR of 68dB with 28-40dB gain control range and 60MHz sampling rate, occupying 25.68mW power and 0.152 mm2 chip area.