Background:
Operational Transconductance Amplifier (OTA) plays an essential role
in many analog and mixed-signal applications that encourages the researchers to contribute their
work to design suitable structures of OTA for their applications with acceptable performance
parameters.
Methods:
The linearity of an OTA is one of its key performance parameters, which affects the performance
of the overall system whereas the transconductance value of OTA (Gm) contributes to decide
its application area. Low transconductance OTA finds its application in biomedical and neural
networks while OTA with higher transconductance is suitable for wireless communication. In any
system, it is desirable to obtain a linear voltage-to-current conversion, i.e., OTA, hence various linearization
techniques have been reported to linearize the OTA.
Results:
In the last two decades, various OTA structures have been reported with linear voltage-tocurrent
conversion. Some researchers used attenuation by means of different circuit approaches to
linearize the OTA or some used cancellation of nonlinearity terms by using different circuit implementation
techniques. Researchers used some other methods also to linearize the OTA viz
source degeneration, square root technique and mobility compensation.
Conclusion:
The purpose of this paper is to provide a brief survey of various popular linearization
techniques reported in the past.
