Phase Locked Loops Using Quadrature Detector Integrated Circuits

Phase locked loops built around quadrature detector I.C.'s are extremely simple and low in cost. Using one type of I.C. and a suitable voltage controlled oscillator, phase locked loops for AM detectors, CD-4 record decoders, video player detectors and FM broadcast receiver detectors are easily designed and built. The same design equations apply to all types of loops and necessary constants are easily measured or calculated. Performance in all cases exceeds that of conventional detectors or even I.C.'s designed specifically for the purpose.