A bandwidth-tunable bioamplifier with voltage-controlled symmetric pseudo-resistors

作者：Shiue Muh Tian; Yao Kai Wen^*; Gong Cihun Siyong Alex

来源：Microelectronics Journal, 2015, 46(6): 472-481.

DOI：10.1016/j.mejo.2015.03.013

• Pseudo-resistor
• Bioamplifier
• Subthreshold region
• Dynamic range
• Linearity

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-mu m standard CMOS process, achieving a gain of 40.2 dB with 10.35-mu W 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 mu V-rms from 6.3 Hz to 9.5 kHz and 5.54 mu V-rms from 250 Hz to 9.5 kHz, and a tunable cutoff-frequency from 6.3-600 Hz were demonstrated to prove our design.

• 出版日期2015-6
• 单位中央民族大学; 长春大学