Design of Electronic Tunable CMOS OTA : A Comparative Study

The design of tunable operational transconductance amplifier with wide linear range has become increasingly challenging with the scaling in the power supply voltage. Use of control voltage for the purpose of tunability often results in narrow linear range. With the reduction in supply voltage in recent years the use of voltage as the control parameter has even become more difficult. Bias current can be used for controlling gain but it requires high supply voltage. This paper is a study of various techniques that can be used to achieve electronic tunability in CMOS OTA