Design of 0.4V, 386nW OTA using DTMOS technique for biomedical applications

An ultra-low-voltage ultra-low-power operational transconductance amplifier (OTA) using dynamic threshold MOS (DTMOS) technique is presented in this paper. The proposed topology is based on a bulk and gate driven input differential pair employs a gain-stage in the Miller capacitor feedback path to improve the pole-splitting effect. The circuit is designed in the 0.18μm CMOS technology. The simulation results show that the amplifier has a 91dB open-loop DC gain and a unity gain-bandwidth of 111.4 kHz while operating at 0.4V supply voltage. This technique show remarkable enhancement in unity gain-bandwidth and also in DC gain compared to the bulk driven input differential pair technique. The total power consumption is as low as 386nW which makes it suitable for low-power bio-medical applications.