| 摘要 |
PURPOSE:To set optionally a clipping level with a simple constitution by providing a constant current supply circuit regulating the lower limit of the clipping level and a control means limiting an output current of an output transistor(TR) so as to regulate the upper limit of the clipping level. CONSTITUTION:When an input signal is applied to a base of the TRQ1, an output signal corresponding to an input signal is generated at an output terminal 15. When a voltage level of the output signal is low, the minimum value of a current flowing to resistors R1, R2 is regulated by a constant current source I2 and the lower limit of the output signal is clipped by the voltage level V2 being I2 (R1+R2). When the voltage level of the output signal is high and the collector current of a TRQ6 is larger than the output current of a constant current source I3, the TRQ6 is driven to control an output current of a current mirror circuit 14, and the collector current of the TRsQ6, Q5 is controlled so as not to flow more than the output current of the constant current source I3, and the upper limit of the output signal is clipped by a voltage level V1 being (I3-I2).(R1+R2). |
