Design and testing of a PI controller ASIC

This paper describes the design and testing of an application specific integrated circuit (ASIC) which provides the functionality of a digital proportional plus integral error actuated controller with auxillary feedback. The ASIC controller can provide discrete time control of a range of continuous time systems by receiving analogue inputs via a single multiplexed analogue to digital converter and providing an analogue output via a digital to analogue converter. The controller has a fixed sampling rate but allows both proportional and integral gains to be adjustable using a digital control word. The controller functions are performed in hardware on a single ASIC so providing for the same functionality as a software algorithm without the need for embedded software.