| 摘要 |
PURPOSE: To provide a bidirectional current drive circuit which can easily and precisely control a load element by controlling a source transistor Tr and a sink Tr via two TRs of an input drive control means and then supplying a bidirectional current to the load element. CONSTITUTION: An input control signal 23 of a positive voltage form of an input terminal 22 is supplied to the base of a control Tr via a resistor 30, and a Tr Q5 conducts. As a result, the collector-emitter current of the Tr Q5 supplied via the resistor 30 starts the base of a drive current source Tr Q1 to make the Tr Q1 conduct concurrently with a sink Tr Q4 . Therefore, the Tr Q5 functions to turn on the Tr Q1 and at the same time the Tr Q4 completes a circuit path for the drive current flowing toward an arrow A via a load 13. In the same mode, a high-level signal 25 makes a control Tr Q6 conduct at an input terminal 24. At the same time, a current source Tr Q2 and a sink Tr Q3 conduct. Thus, an inverse current path is completed via the load 13 for the current flowing toward an arrow B. In such a constitution, a bidirectional current drive circuit is obtained for execution of the accurate control. |
