| 摘要 |
Controllable audio amplifier for miniature radio receiver, such as paging receiver, provided as a hybrid module which includes a monolithic circuit chip on a circuit providing base. A pre-amplifier on the thick film applies signals to a differential power amplifier on the integrated circuit. The differential amplifier has two balanced sides, each having a plurality of stages and a direct current feedback loop with a voltage reference for providing bias stability for the class B output stages. A voltage regulator on the thick film is controlled by transistors on the integrated circuit to provide operating voltage to the amplifier only when the proper control signal is received. A control circuit turns on the regulator in response to various control signals, and includes a latching circuit for holding the amplifier on subject to reset by multiple means. This can be responsive to a voltage from a decoder or a receiver squelch circuit. Manual on and off operation is also provided. |
