| 摘要 |
PURPOSE:To increase the amplifying gain with no lowering of the function of the differential amplifier but by changing the connecting method between the first-step amplifier and the differential amplifier pair, thus increasing the rising speed when the power source is made. CONSTITUTION:Input terminal 1 is connected to the base of the first-step amplifying trnsistor TR14; AC by-pass capacitor 9 is connected to the emitter of TR14; and the collector is connected to power source 17 via load resistance 12. The output signal extracted through the collector of TR14 is connected to output terminal 2 via TR5 for amplification of the next step, and furthermore the voltage of constant current source TRs21 and 22 are connected to emitters of each of differential amplifying pairs TRs 3 and 4. At the same time, DC feedback resistance 20 is connected between emitters of TRs 3 and 4 each, and the collector of TR3 is connected to the emitter of TR14. And then the base of TR14 and the collector of TR4 plus the base of TR4 are connected to reference constant voltage source 15, power source 17 and terminal 2 respectively. And the charging is accelerated for capacitor 9 connected to the emitter of TR14 when the power source is made, and then TR14 is actuated as the DC earth. In this way, the AC gain can be increased. |
