Simple Realizations of Current-Mode and Voltage-Mode PID, PI and PD Controllers

Abstract

This paper presents new circuits for realizing both current-mode and voltage-mode proportional-integral- derivative (PID), proportional-derivative (PD) and proportional-integral (PI) controllers employing second- generation current conveyors (CCIIs) as active elements. All of the proposed PID, PI and PD controllers have grounded passive elements and adjustable parameters. The controllers employ reduced number of active and passive components with respect to the traditional op-amp-based PID, PI and PD controllers. A closed loop control system using the proposed PID controller is designed and simulated with SPICE. I. INTRODUCTION The proportional-integral-derivative (PID), proportional- integral (PI) and proportional-derivative (PD) controllers with adjustable parameters are widely used in many industrial control systems, and usually have been implemented with operational amplifiers (op-amps). PID controller realizations using op-amps employ excessive number of active and passive components. Current conveyors, especially plus-type second-generation current conveyors (CCII+s) have larger bandwidth and dynamic range, and also greater linearity than op-amps (1). Employing only CCII+s simplifies the configuration thus gyrator (2), synthetic floating inductances (3-4), voltage- mode filter (5) and transfer function synthesis (6-7) employing only CCII+s have been reported in the literature. Despite of several circuits such as derivative, integral, proportion and summer constructed with op-amps (8-9) that can be used to implement PID, PI and PD controllers, current conveyors have not been used to realize PID, PD and PI controllers in the literature so far. In this paper, novel current-mode and voltage-mode PID, PI and PD controllers employing CCII+s as active elements are proposed. In the proposed current-mode controllers, output currents are taken from high impedance terminals of the CCII+s. Also input voltages are applied to the Y-terminals of the CCII+s in the presented voltage- mode PID, PI and PD controllers. These properties make the proposed circuit ideal for using in cascaded systems. All the proposed controller realizations employ only grounded passive components, and do not require passive element matching so the circuits are suitable for integration. The PID, PI and PD parameters can be selected independently. Also simulations are performed using SPICE program to verify the theoretical analyzes.