| 摘要 |
A load driving circuit includes a pair of push-pull circuits formed of bipolar transistors. A load is connected between the output terminals of the push-pull circuits and the polarity of a current flowing in the load can be changed to drive the load. The pair of push-pull circuits are controlled by means of an output transistor driving circuit. The output transistor driving circuit includes first and second driving transistors for driving output transistors constituting the push-pull circuits and first and second control transistors for preventing the flow of a through current. The emitter and collector of the first control transistor are respectively connected to the emitter and base of the first driving transistor or the emitter and base of the output transistor arranged on the power source side and constituting one push-pull circuit. The emitter and collector of the second control transistor are respectively connected to the emitter and base of the second driving transistor or the emitter and base of the output transistor arranged on the power source side and constituting another push-pull circuit. The conduction states of the first and second driving transistors are controlled by signals set in an inverted phase. The conduction state of the first and second control transistors are respectively controlled by signals which is in the same phase as the signal for controlling the second and first driving transistors. |
