| 摘要 |
PURPOSE:To prevent an excess current from flowing to an output stage transistor (TR) even when the level of an output terminal of a binary signal voltage is controlled externally by adopting a constitution that an object binary signal voltage is obtained from the output terminal of a current mirror circuit. CONSTITUTION:TRs Q11, Q12 constitute a current mirror circuit. A binary signal current Ii/0 is given to the input terminal of the current mirror circuit, that is, the collector of the TR Q12 of diode connection from a current source I11. On the other hand, a load resistor RL is inserted between a power supply Vcc and the collector of the TR Q11 being an output terminal. The current source I11 is a voltage/current conversion circuit and an emitter follower TR Q13 and a resistor R11 convert an input binary signal voltage Vi/0 into a binary signal current Ii/0. |
