A Monolithic Color Processing Circuit

The application of linear medium scale integration principles to the color TV receiver has led to an economical monolithic integrated circuit which performs the functions of 3.58 MHz color signal reference generation and chroma demodulation. Operation of the circuit in either an APC reference loop, burst injection locked oscillator mode or as a crystal ringing amplifier allows the receiver designer the necessary flexibility to meet his goals. Furthermore, a wide latitude in colorimetry can be achieved by proper choice of relatively few external components. The monolithic circuit, which measures 44 × 58 mils, contains reactance control element, reference amplifier/oscillator, buffering stages to provide signals for phase detector and color kill functions, and two demodulators. Utilization of this IC in the various color TV receiver systems is discussed.