Background: This paper presents a low noise and low distortion telescopic operational
trans-conductance amplifier (OTA) that is suited to biomedical signal processing. In our proposal,
source degeneration using CMOS transmission gate is introduced in telescopic OTA to realize current-
voltage negative feedback. The negative feedback degenerates Gm, reduces flicker noise and reduces
Methods: The circuit is simulated by using TSMC 90nm CMOS process technology with 1.8V supply
voltage. We obtained promising simulation results that show THD less than -90dB and flicker
noise 60 nV at 4kHz corner frequency.
Result: The frequency response plot reveals that our circuit offers a voltage gain of 63dB with negative
feedback and achieves a phase margin of about 70 degrees. Thus, this topology is a feasible solution
for low noise and low distortion biomedical signal amplifier circuits.
Conclusion: A highly linear and low noise telescopic OTA topology was proposed in this paper. A
simple but efficient technique of source degeneration is used with negative feedback to achieve low
distortion and low noise.