The design of an operational transconductance amplifier (OTA)

• Main Author: Yap, Deep
• Other Authors: Siek Liter
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/70770
• Institution: Nanyang Technological University

Operational amplifiers are commonly used in analog circuit designing, especially operational transconductance amplifier (OTA)which is used to convert input voltage signal into an output current. However, OTA could only drive capacitive load, therefore an extra output stage is needed. The OTA is designed using the nested- current mirror technique, which is able to deliver a DC gain of 70dB, phase margin more than 60 degrees and with slew rate of 8mV/μs for a capacitive load of 0.5nF. The output stage is designed in a class AB configuration, which would able to sink and source 1mA current to a 1kΩ resistive load while maintaining output swing with one overdrive voltage less than the supply voltage. The CMOS technology used is 0.18μm.