A 0.5 V, 20 µW pseudo differential 500 kHz Gm-C low pass filter in 0.18 µm CMOS technology

Scaling of supply voltage due to shrinking in the device sizes has lead to bulk driven circuit techniques specially for analog circuits that operate at low supply voltages. In this paper we present a bulk driven pseudo differential low power, continuous time Cochlea 2
^nd
order Butterworth low pass filter operating at a supply voltage of 0.5 V. The filter uses Gm-C technique in 0.18 μm n-well standard CMOS process and has a bandwidth of 500 kHz. Simulations results have shown that the filter offers a dynamic range of 48 dB while consuming a power of 20 μW. Simulated Figure of Merit (FOM) is found to be 0.52 fJ and is found to be the lowest among similar low voltage filters found in literature. The percentage change in transconductance is less than ±5% for temperature variation of 0-70°C at 0.5 V supply voltage and across five process corners.