Control (management)

Voltage

Engineering

Biasing

Materials science

Operational amplifier

Amplifier

Computer science

Business

Boosting (machine learning)

Slew rate

Transistor

Transconductance

Electronic engineering

Artificial intelligence

Gain–bandwidth product

Chemistry

Cascode

Control theory (sociology)

Class (philosophy)

CMOS

Operational transconductance amplifier

Optoelectronics

Machine learning

Electrical engineering

IEEE Journal of Solid-State Circuits

A super class-AB version of the recycling folded cascode (RFC) operational transconductance amplifier (OTA) is proposed. The use of an adaptive bias circuit for the input differential pair provides dynamic current boosting and increased gain-bandwidth product (GBW). Moreover, use of local common-mode feedback (LCMFB) at the load of the differential pair further improves these performance parameters and provides high current efficiency. Measurement results of a test chip prototype fabricated in a 0.5-μm CMOS process show an increase in slew rate and GBW by a factor of 34 and 3, respectively, versus the conventional RFC OTA using the same supply voltage and bias currents. Overhead in other performance metrics is small.

Super Class-AB Recycling Folded Cascode OTA