| 摘要 |
PURPOSE:To simplify the circuit constitution and also to make the multiplexer suitable for formation of integrated circuit by constituting a processing circuit processing a right signal and a left signal of a stereo with an amplifier circuit and a current mirror circuit. CONSTITUTION:Processing circuits 20, 30 are constituted identically. The processing circuit 20 includes signal amplifier circuits 201, 201 and current mirror circuit 203, 204. In the processing circuit 20, the left signal at a terminal L is amplified by the signal amplifier circuits 201, 202. In this case, since transistor TRQ100 acts like a constant current source, the amplifier circuit 202 amplifies the left signal in response to the level. The amplified left signal is given to a differential amplifier 11 via both the current mirror circuits 203, 204. This is applied similarly to the right signal. Thus, the circuit constitution is simplifed and no bypass capacitor is required. |
