Programmable Floating Inverter-Based Digital OTA for Electrochemical Biosensing

In this paper, an ultra-low voltage (ULV), ultra-low power (ULP), programmable Floating Inverter (FI)-based Digital Operational Transconductance Amplifier (FI-DIGOTA) for electrochemical biosensors is presented and demonstrated in 130 nm CMOS technology. The proposed FI-DIGOTA operates at a power supply voltage ranging from 300 mV to 500 mV and drives a capacitive load up to units of µF, which is consistent with the double-layer capacitance of a commercial screen-printed electrode in a physiological solution. The DC gain ranges from 41.18 dB to 62.15 dB, the Gain-Bandwidth Product (GBW) spans from 25.9 Hz to 293 Hz with a power consumption ranging from 3.05 nW to 1,572.55 nW.