## Abstract

This article presents a compact analog front-end (AFE) circuit for ultrasound receivers with linear-in-dB continuous gain control for time-gain compensation (TGC). The AFE consists of two variable-gain stages, both of which employ a novel complementary current-steering network (CCSN) as the interpolator to realize continuously variable gain. The first stage is a trans-impedance amplifier (TIA) with a hardware-sharing inverter-based input stage to save power and area. The TIA’s output couples capacitively to the second stage, which is a class-AB current amplifier (CA). The AFE is integrated into an application-specific integrated circuit (ASIC) in a 180-nm high-voltage BCD technology and assembled with a 100 -pitch PZT transducer array of 8 <inline-formula> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 8 elements. Both electrical and acoustic measurements show that the AFE achieves a linear-in-dB gain error below <inline-formula> <tex-math notation="LaTeX">$\pm$</tex-math> </inline-formula>0.4 dB within a 36-dB gain range, which is <inline-formula> <tex-math notation="LaTeX">$>$</tex-math> </inline-formula>2<inline-formula> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> better than the prior art. Per channel, the AFE occupies 0.025 area, consumes 0.8 mW power, and achieves an input-referred noise density of 1.31 .

Original language | English |
---|---|

Pages (from-to) | 1-13 |

Number of pages | 13 |

Journal | IEEE Journal of Solid-State Circuits |

DOIs | |

Publication status | E-pub ahead of print - 2022 |

## Keywords

- Application-specific integrated circuit (ASIC)
- Capacitors
- Gain
- Imaging
- Interpolation
- pitch-matched analog front-end (AFE)
- time-gain compensation (TGC)
- Trajectory
- trans-impedance amplifier (TIA)
- Transducers
- Ultrasonic imaging
- ultrasound imaging
- variable gain amplifier (VGA)