Muting amplifier

Abstract

Abstract PURPOSE: To make the muting state possible, and to prevent the occurrence of click tone, by setting a prescribed current, which is applied to the first current Miller, to zero to make both differential input stages into the breaking state. CONSTITUTION: Transistors (TR) Q 18 and Q 19 which constitute a differential stage for switching, bias circuits R 20 and R 21 of the TRQ 19 , a switching control terminal 8, and TRs Q 16 and Q 17 which constitute the second differential input stage are provided newly. When a base voltages VSW of the terminal 8 is lower than a base voltage VB of the TRQ 19 , TRs Q 18 and Q 19 are turned on and off respectively, and the collector current of a TRQ 2 is flowed to first differential input stages TRs Q 3 and Q 4 , and an input voltage VIN of an input terminal 6 is amplified. At this time, input stages TRs Q 16 and Q 17 are turned off together, and an input voltage V'IN is muted. COPYRIGHT: (C)1982,JPO&Japio

Inventors

• 👤 Kinji Kawamoto

Bibliographic Details