This paper presents a low-voltage nano-power multiple-input operational transconductance amplifier (MI-OTA) with high linearity performance and increased input voltage swing.The enhanced performances are achieved thanks to employing several techniques as the bulk-driven, source-degeneration, self-cascode and Brackets negative conductance along with the concept of the input signal attenuation formed by multiple-input MOS transistor.The MI-OTA is widely tunable that serves for biological signals processing.A 3rd-order Butterworth band-pass filter (BPF) for electrocardiogram (ECG) signal processing with 55.
8 dB dynamic rang is presented.The MI-OTA circuit is designed for 0.5V voltage supply and offers a 0.22% total harmonic distortion (THD) for silicone-toys 0.
2Vpp input signal with total power consumption of 13.4nW.Extensive simulation results including Monte Carlo analysis and process, voltage, temperature (PVT) corners using the $0.18mu ext{m}$ CMOS technology from TSMC confirm the characteristics of the proposed MI-OTA and the filter.