A Low-Power Current-Reuse LNA for 3D Ultrasound Beamformers

Yohei NAKAMURA
Shinya KAJIYAMA
Yutaka IGARASHI
Takashi OSHIMA
Taizo YAMAWAKI

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E104-A    No.2    pp.492-498
Publication Date: 2021/02/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.2020GCP0011
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
amplifier,  current-reuse,  driver,  ultrasound,  LNA,  

Full Text: FreePDF(2.3MB)
Summary: 
3D ultrasound imagers require low-noise amplifier (LNA) with much lower power consumption and smaller chip area than conventional 2D imagers because of the huge amount of transducer channels. This paper presents a low-power small-size LNA with a novel current-reuse circuitry for 3D ultrasound imaging systems. The proposed LNA is composed of a differential common source amplifier and a source-follower driver which share the current without using inductors. The LNA was fabricated in a 0.18-μm CMOS process with only 0.0056mm2. The measured results show a gain of 21dB and a bandwidth of 9MHz. The proposed LNA achieves an average noise density of 11.3nV/√Hz, and the 2nd harmonic distortion below -40dBc with 0.1-Vpp input. The supply current is 85μA with a 1.8-V power supply, which is competitive with conventional LNAs by finer CMOS process.

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