An 1-V, 74-dB, sub-Hz Gm-C filter based on a modular transconductance reduction technique

An 1 V 33.2 pS OTA, which consumes power at 5.5 nW, is proposed. This OTA employs the input voltage pre-attenuation technique which based on CMOS common drain circuits with diode connected load to reduce the overall transconductance gain. The linear range of this proposed OTA is 370 mV for 1 % transconductance gain variation. Additionally, the pseudo-differential G_M-C 2^nd order LPF based on this OTA topology which dissipates 82 nW at 1 V supply with 74 dB dynamic range and cutoff frequency from 0.69 Hz - 76 Hz has been demonstrated. With comparison to the original work of the pre-input voltage attenuated OTA; the power dissipation, output voltage swing, IRN and DR are improved. All results of this work are simulated on 0.35 μm standard CMOS process.