Conventional Function Circuits
Krishnagiri Chinnathambi Selvam · 2021
Most conventional function circuits use a bipolar transistor as a predictable non-linear element. Its base emitter voltage is a logarithmic function of its collector current. Logarithmic amplifiers are used in many functions like multiplying, dividing, squaring, and square rooting. Log-antilog multipliers, field effect transistors (FETs) as voltage variable resistor multipliers, variable trans-conductance multipliers, Gilbert multiplier cells, triangle wave averaging multipliers, and quarter squarer multipliers are conventional multipliers. Log-antilog MCD, MCD using FETs, and MCD using MOSFETs are conventional MCDs. For small source-drain voltages, a FET acts as a controlled resistor whose resistance is inversely proportional to the gate source voltage.