| 摘要 |
PURPOSE:To secure an assured protection by using the NPN transistor featuring a large current amplification ratio to the PNP output transistor for the protection purpose among the complementary transistors. CONSTITUTION:The emitters of complementary NPN and PNP output transistors Tr12 and Tr13 are connected to the output terminals via resistance respectively; protecting NPNTr15 featuring a large current amplification ratio is connected between the base electrode and the output terminal of PNPTr13; and diode D13 is connected forward between the base electrode and the output terminal of Tr15. Here, Tr15 can control the large current flowing to the output transistor, so the output transistor can be protected assuredly. |
