DESIGN AND IMPLEMENTATION OF PID CONTROLLERS USING CM BUILDING BLOCKS

Abstract

Proportional plus Integral plus Derivative (PID) controllers are the mainstay of most of the control systems employed in different process industries. Traditional PID controllers have been implemented using the voltage mode operational amplifiers (VOA). Performance of these VOA based PID controller is limited by the performance of the traditional VOA. In this dissertation, current mode (CM) and voltage mode (VM) analog PID controllers have been studied & implemented. The CM and VM building blocks chosen for study and implementation of the PID controllers are (i) OTA, (ii) DOCC-II, (iii) CFA and (iv) CDBA. The PID controllers have been implemented in PSPICE and closed loop performances of some prototype second order system have been studied to establish the workability of these PID controllers. A novel fully differential current- mode PID controller has also been designed and implemented which uses a fully differential implementation of proportional, integral and differential terms.