Multichannel receiver

Abstract

Abstract PURPOSE:To prevent the outputting of a click noise generated at a changing-over time in a receiver using a PLL frequency synthesizer, by detecting the transient state at the channel changing-over tme by a clock detection circuit which operates by the output of a phase comparator. CONSTITUTION:In the multichannel receiver which employs as a local oscillator the PLL frequency synthesizer composed of voltage control oscillator 8, reference frequency oscillator 11, programable divider 9, phase somparator 12, charge pump 13, LPF15, etc., the unlock state at the channel changing-over time is detected by the FF, logical gate circuit and lock detection circuit 14 provided to comparator 13, and the output of this detection circuit is applied to the switching method of muting circuit 6, so that the muting operation will stop the click noise at the changing-over time outputted from sound amplifier 7.

Inventors

• 👤 Noriaki Kato

Bibliographic Details