Open AccessDesign of Two-Stage Fully-Differential Operational Transconductance Amplifier Using a Standard 0.35µm CMOS Process
Author(s) -
T. V. F. Abaya,
Frederick Ray I. Gomez
Publication year - 2019
Publication title -
asian journal of engineering and technology
Language(s) - English
Resource type - Journals
ISSN - 2321-2462
DOI - 10.24203/ajet.v7i1.5680
Subject(s) - operational transconductance amplifier , fully differential amplifier , operational amplifier , phase margin , direct coupled amplifier , electronic engineering , transconductance , cascode , cmos , differential amplifier , amplifier , electrical engineering , computer science , engineering , transistor , voltage
The paper presents a design of a two-stage fully-differential operational transconductance amplifier (OTA) for a 10-bit 40-Msamples/s Nyquist rate analog-to-digital converter (ADC) using  a standard 0.35µm complementary metal-oxide semiconductor (CMOS) process. A telescopic cascode topology is implemented as main stage, with common source amplifiers as output stage for the differential outputs. The open loop amplifier achieved a gain of 108dB, while the closed loop gain is at 12dB with settling time of less than 11ns for an accuracy of 0.5%. Total output noise achieved is 63.4uVrms. Loop unity gain bandwidth is 205MHz with phase margin of 77.6°. The design has a dynamic range of 88.3dB, and power consumption of 26.6mW from a 3V supply.