| 摘要 |
PURPOSE:To obtain specific base clipping characteristics even to a small-amplitude signal by comparing amplitude values of respective input signals to a specific value, and mixing signal currents which are weighted on the basis of the comparison results with the opposite polarities. CONSTITUTION:The differential amplifier circuit 5 consisting of transistors (TR) 13 and 14 and the differential amplifier circuit 6 consisting of TRs 13 and 14 are supplied with an input signal from a common input terminal 1 and signal currents obtained by the circuits 5 and 6 corresponding to the input signal are mixed together in opposite-polarity relation by the mixing circuit 7 consisting of a TR17 and a resistance 19 and the mixing circuit 8 consisting of a TR18 and a resistance 20. At this time, those signal currents are equal when the input signal a' has a constant voltage and the amplitude of the input signal has the specific amplitude, and different from each other when the amplitude is larger than the specific value, turning on and off switching elements 9 and 10. The values of the resistances 19 and 20 are optional, so clipping width is set between 0 and the sum of the on voltages of both elements. |
