Designing an Inverter‑based Operational Transconductance Amplifer‑capacitor Filter with Low Power Consumption for Biomedical Applications

The operational transconductance amplifer‑capacitor (OTA‑C) flter is one of the best structures for implementing continuous‑time flters. It is particularly important to design a universal OTA‑C flter capable of generating the desired flter response via a single structure, thus reducing the flter circuit power consumption as well as noise and the occupied space on the electronic chip. In this study, an inverter‑based universal OTA‑C flter with very low power consumption and acceptable noise was designed with applications in bioelectric and biomedical equipment for recording biomedical signals. The very low power consumption of the proposed flter was achieved through introducing bias in subthreshold MOSFET transistors. The proposed flter is also capable of simultaneously receiving favorable low‑, band‑, and high‑pass flter responses. The performance of the proposed flter was simulated and analyzed via HSPICE software (level 49) and 180 nm complementary metal‑oxide‑semiconductor technology. The rate of power consumption and noise obtained from simulations are 7.1 nW and 10.18 nA, respectively, so this flter has reduced noise as well as power consumption. The proposed universal OTA‑C flter was designed based on the minimum number of transconductance blocks and an inverter circuit by three transconductance blocks (OTA).