Digital serial loop filter for high speed control systems

摘要

A digital programmable loop filter for high frequency control systems applications utilizing a serial processing technique on pulse densities. The loop filter contains a proportional signal path and an integral signal path. A 4-time-slot sequencer time-multiplexes the serial proportional and integral signals to emulate a 1-pole/1-zero filter. An acquisition speed control circuit controls the acquisition time as well as step sizes of the scaler (proportional path) and the integrator (integral path) to provide loop variable programmability.