Resumo:
This work presents a topology of a low power Transconductance Operational Amplifier (OTA)
for the compensation of Common Mode Rejection Ratio (CMRR), in which the transistors
operate in the strong inversion mode. Initially, a theoretical review of the differential amplifier
and OTA is presented. Then, an OTA architecture was proposed based on a symmetric
differential amplifier structure with additional transistors in parallel to the input MOS
transistors, in order to increase the CMRR rate, as well as the proposed compensation strategy.
The OTA was designed using IBM 130 nm CMOS technology. Monte Carlo and Corner
simulations were performed to analyze the compensation strategy and to obtain a more realistic
assessment. The results obtained demonstrate that the proposed circuit for common mode
control operates correctly, since the proposed OTA enabled common mode control in parallel,
obtaining a CMRR of 87.34 dB and power consumption of 9.65 μW, validating its compatibility
with low power circuits.
