Design and Analysis of Two-Stage Operational Transconductance Amplifier (OTA) using Cadence tool

This paper presents the design and analysis two-stage operational transconductance amplifier (OTA) for use in switched-capacitor (SC) circuits. The existing design methods for two-stage OTAs often lead to sub optimal solutions because they decouple inter-related metrics like noise and settling performance. In our approach, the cadence tool is used to analysis the transient response, AC response and phase plot of the OTA and settling time has been observed on the simulation. For the optimization routine, there is no need to interface with a circuit simulator because all significant devices parasitic are included in the tool. The simulation results show that a 90nm prototype amplifier achieves the settling time of 1.6 ns with reduced integrated noise while consuming 2.4 mW from a 1.2V power supply with phase plot for 175 degree.