| 摘要 |
PURPOSE:To enable the observation of a signal waveform at an input terminal or an output terminal of a linear amplification circuit from an output signal thereof, by forming the linear amplification circuit having a high load driving capacity on a chip on which a logical circuit with a high input impedance with the input terminal connected to an input terminal or an output terminal of the logical circuit. CONSTITUTION:When observing a waveform at the input or output of a logical IC circuit 1, the terminal 3 corresponding to the observation of the desired waveform is connected to a wire section 5 for connecting wires linked to the input terminal 4 of a linear amplification circuit 2, a coaxial cable is connected between the wire section 5 and a GND pad 8 and the cable is extended to be connected to an observation unit. The waveform observation at the input or output of the logical IC circuit 1 done in this way permits a better observation of waveforms avoiding troubles involved in the conventional waveform observation technique. Such a waveform observation can be executed because the differential amplification circuit 23 and an emitter follower circuit 24 composing the linear amplification circuit 2 are high in the input impedance but low in the output impedance. |
