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Title An Analog Front-end Amplifier with Seamless Discrete Time-gain Compensation for Ultrasound Scanner
Authors (Min-Hyeong Son) ; (Ji-Yong Um)
DOI https://doi.org/10.5573/JSTS.2023.23.6.389
Page pp.389-395
ISSN 1598-1657
Keywords Analog front-end amplifier; programmable gain amplifier; seamless time-gain compensation; operational amplifier; ultrasound scanner
Abstract This paper proposes an analog front-end (AFE) amplifier with seamless discrete time-gain compensation (TGC) for ultrasound scanners. The AFE amplifier consists of a preamplifier and a programmable gain amplifier (PGA). A real-time TGC operation is typically accomplished with gradual gain increments in PGA. To achieve a seamless gain transition in PGA, this work proposes a preset switching scheme for an initialization of operating points in PGA. In addition, current-reuse operational amplifiers with dynamic push-pull current sources are deployed in the AFE amplifier to further enhance a transient response. The proposed AFE implemented in a 180-nm BCD process occupies 0.19 mm2, and consumes 2.3 mW. The AFE achieves a gain range from 34.3 dB to 50.5 dB with four gain steps, and a transient interval less than 18 ns during a gain transition.