| 摘要 |
PROBLEM TO BE SOLVED: To provide a transistor output circuit by which the circuit is simplified and economized by reducing the number of parts and also a packaging substrate realized where a mounting space is improved and which is shared by an NPN transistor and a PNP transistor. SOLUTION: The transistor output circuit is provided with a protection circuit constituting a over-current preventing circuit and a latch circuit for the NPN transistor TR2 (an output transistor) of an output circuit, which consists of a diode D2, the NPN transistor QN, the PNP transistor QP, resistors R5, R7 and R8 and a capacitor C2. When an over current IL is made to flow in the NPN transistor TR2, the NPN transistor TR2 is held (latched) to be an off-state so that the NPN transistor TR2 is prevented from being deteriorated and destroyed. |
