| 摘要 |
PURPOSE:To obtain a push-pull amplifier circuit featuring a small amount of notching distortion by connecting the constant current source to the emitter of the transistor and then supplying the signal current to the load via the diode. CONSTITUTION:When the output features the positive half wave, NPN transistor Q1 and diode D1 conduct. And D1 is cut off in the case of the negative half wave, but Q1 keeps the conduction state via constant current source I1. And in case the output features the positive half wave with PNP transistor Q2 and diode D2, D2 is cut off but Q2 is kept under the conduction state via constant current source I2. Both Q2 and D2 conduct in the case of the negative half wave. The notching distortion depends on the delay time of the diode which is caused when diodes D1 and D2 change from the conduction state to the cut-off state and vice versa. And the delay time of the diode is shorter than that of the transistor, thus reducing the notching distortion. |
