Designing an Inverter-based Operational Transconductance Amplifi er-capacitor Filter with Low Power Consumption for Biomedical Applications

The operational transconductance amplifi er-capacitor (OTA-C) fi lter is one of the best structures for implementing continuous-time fi lters. It is particularly important to design a universal OTA-C fi lter capable of generating the desired fi lter response via a single structure, thus reducing the fi lter circuit power consumption as well as noise and the occupied space on the electronic chip. In this study, an inverter-based universal OTA-C fi lter 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 fi lter was achieved through introducing bias in subthreshold MOSFET transistors. The proposed fi lter is also capable of simultaneously receiving favorable low-, band-, and high-pass fi lter responses. The performance of the proposed fi lter 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 fi lter has reduced noise as well as power consumption. The proposed universal OTA-C fi lter was designed based on the minimum number of transconductance blocks and an inverter circuit by three transconductance blocks (OTA).