A 0.816 nW 12.3 pS Tunable Low-Gm Transconductor for Bio-electrical Signal Acquisition
Abstract
A transconductance amplifier with low-Gm is indispensable for applications that acquire low-frequency bioelectric signals. This paper proposes a subthreshold bootstrapped low-Gm transconductor based on body-input. The input topology of the transconductor consists of two transistors with body inputs and a source degeneration resistor. The outputs of the two transistors are connected to the resistor to bootstrap the voltages at these terminals and increase the equivalent resistance. An area-efficient serial-parallel current division network is further adopted to reduce the Gm of the transconductor. Meanwhile, programming the bias voltage can tune the G m value. The circuit is designed using a standard 0.18 μm CMOS process. Simulations verify the characteristics of the proposed transconductor. The post-layout simulation results show that the transconductor’s Gm value is tunable within a range of a few hundred pS. The minimum achievable Gm is 12.3 pS, and the linear input range is ±150 mV. The input referred noise power spectral density (PSD) of the transconductor is 13.7 μV/√Hz. It consumes 0.816 nW of power with 0.8 V supply voltage and occupies an area of 0.0057 mm^2.
Feng Yan
PhD Student
My research interests include circuit design of analog front end for biomedical applications and sensor interfaces.
Bingjun Xiong
PhD Student
My research interests include circuit design of optical receivers and references.
Wenji Mo
Master’s Student
My research interests include circuit design of low-power RISC-V processors and self-powered SoCs.
Kangkang Sun
PhD Student
My research interests include circuit design of analog to digital converter for biomedical applications and SAR ADC.
Jian Guan
PhD Student
My research interests include the design of solar cells and energy harvesting circuits.
Jingjing Liu
Associate Professor
My research interests include low-power smart micro-sensor integrated circuit design, image sensors, biomedical sensors, and energy harvesting circuits.