A Low Noise TIA with Continuous Time-Gain Compensation for Ultrasound Transducers

Abstract

This paper presents a low noise power-efficient TIA for capacitive-micromachined-ultrasonic transducers (CMUT) to ensure the high-quality ocular ultrasound images. Implemented in CMOS technology, the TIA adopts a source input structure to achieve broadband impedance matching. The use of noise cancellation and capacitive feedback optimizes the noise performance of the amplifier. A continuous time-gain compensation circuit is built in the TIA by adjusting the positive and negative resistance loads, which are composed of the voltage -controlled MOS array. Simulation results show that the TIA achieves a $\boldsymbol{1.9}\mathbf{pA}/\sqrt{}$ Hz input referred noise at 18MHz center frequency of the echoes while consuming only 0.18mW.