| 摘要 |
<p>PURPOSE:To lower a necessary input voltage to about half of a conventional voltage and to allow it to have a high input resistance characteristic by constituting a bias circuit of a first and a second transistors in which a base and an emitter are connected in series and which generate a necessary bias voltage, converting one transistor of them to a multi-collector and supplying a necessary base current. CONSTITUTION:A base of a transistor Q2 is connected directly to an input terminal 1, and a transistor Q3 and a multi-connector (collector area is 1:1) transistor Q6 whose polarity is opposite to that of its transistor Q3 is used as a bias circuit. That is, bases of both the transistors Q3, Q6 are connected in common, and also, one of the collector of its transistor Q6 and the other are connected to the base and the input terminal 1, respectively, and to the emitter, a constant-current source 2 is connected. In such a way, the constitution whose input resistance is extremely high can be realized.</p> |
