Band decoder for all-channel digital tuning system
Electronic tuning control system for television
Programming unit for a television tuning phase locked loop
Programmable frequency divider for a television receiver frequency synthesizer Patent #: 4024476
ApplicationNo. 05/695875 filed on 06/14/1976
US Classes:455/180.1, Combined with band selection331/1A, AFC with logic elements455/182.3, Fine tuning455/183.1With frequency synthesizer
ExaminersPrimary: Griffin, Robert L.
Assistant: Ng, Jin F.
Attorney, Agent or Firm
International ClassesH03J 5/02 (20060101)
H03J 5/00 (20060101)
H03L 7/16 (20060101)
H03L 7/193 (20060101)
H03J 7/06 (20060101)
H03J 7/02 (20060101)
AbstractA phase locked loop circuit for use in an automatic frequency synthesizing system. The system includes a programmer circuit which is responsive to a channel number input signal and generates a first digital control signal which is representative of the selected channel number and a second digital control signal which is representative of a predetermined group of channel numbers. A programmable divider is controlled by the programming circuit and generates a digital output signal which causes the phase locked loop circuit to generate a desired system output frequency corresponding to the selected channel number input signal. The phase locked loop circuit includes automatic fine tuning and manual fine tuning features.