An Ultra-Low Power (86 nW) Low-Voltage (0.6 V) Self-Biased Instrumentation Amplifier for Bio-Medical Applications

In this article, an operational transconductance amplifier (OTA)-based self-biased, ultra-low power instrumentation amplifier is proposed. The design is performed in SCL 0.18 μm technology under 0.6 V power supply. The total current drawn from the supply is 144 nA, resulting in ultra-low power consumption of 86 nW. The entire circuit is self-biased by an in-built current reference circuit. The instrumentation amplifier produces a fixed gain of 61 dB with unity gain bandwidth of 4.1 KHz and input RMS noise voltage of 2.01 μVrms. The amplifier is aimed for bio-medical applications and is capable of amplifying a signal as low as 0.5 μV with an ultra-low frequency of 1 Hz also, serving the range of even the weakest possible bio-potential signal quite efficiently.