A bandwidth-tunable bioamplifier with voltage-controlled symmetric pseudo-resistors. Issue 6 (June 2015)

• Record Type: Journal Article
• Authors: Shiue, Muh-Tian; Yao, Kai-Wen; Gong, Cihun-Siyong Alex
• Is Part Of: Microelectronics journal. Volume 46:Issue 6(2015)
• Page Start: 472
• Page End: 481
• Publication Date: 2015-06
• Subjects: Microelectronics -- Periodicals; Microélectronique -- Périodiques; Microelectronics; Electronic journals; Journals - contents and abstracts; Periodicals; 621.3805
• DOI: 10.1016/j.mejo.2015.03.013
• Languages: English
• ISSNs: 0959-8324

Abstract

<abstract abstract-type="author" id="ab0005"> <title id="sect0005">Abstract</title> <sec> <p id="sp0130">This paper describes a bioamplifier that employs a voltage-controlled-pseudo-resistor to achieve tunable bandwidth and wide operating voltage range for biomedical applications. The versatile pseudo-resistor employed provides ultra-high resistance for ac coupling to cancel the dc offset from electrode–tissue interface. The voltage-controlled-pseudo-resistor consists of serial-connected PMOS transistors working at the subthreshold region and an auto-tuning circuit that makes sure the constant (time-invariant) control-voltage of the pseudo-resistor. This bandwidth-tunable bioamplifier is designed in a 0.18-μm standard CMOS process, achieving a gain of 40.2 dB with 10.35-μW power consumption. The designed chip was also used to develop the proof-of-concept prototype. An operation bandwidth of 9.5 kHz, input-referred noise of 5.2 <inline-formula><alternatives><inline-graphic xlink:href="ark:/27927/pgj24fgpr8x" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="si0013.gif" overflow="scroll" id="d13e834" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi mathvariant="normal">μ</mml:mi><mml:msub><mml:mrow><mml:mi mathvariant="normal">V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">rms</mml:mi></mml:mrow></mml:msub></mml:math></alternatives></inline-formula> from 6.3 Hz to 9.5 kHz and 5.54 <inline-formula><alternatives><inline-graphic xlink:href="ark:/27927/pgj24fgr1pn" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="si0014.gif" overflow="scroll" id="d13e850" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi mathvariant="normal">μ</mml:mi><mml:msub><mml:mrow><mml:mi mathvariant="normal">V</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">rms</mml:mi></mml:mrow></mml:msub></mml:math></alternatives></inline-formula> from 250 Hz to 9.5 kHz, and a tunable cutoff-frequency from 6.3–600 Hz were demonstrated to prove our design.</p> </sec> </abstract>