| 摘要 |
PROBLEM TO BE SOLVED: To provide a short protecting circuit for a semiconductor integrated circuit which prevents an overcurrent from flowing to an output terminal if the output terminal short-circuits to a ground level in error. SOLUTION: This circuit is equipped with a 1st transistor (TR) (Q2) which turns off when the level at an output terminal (50) as an external terminal of the semiconductor integrated circuit varies to below a threshold from a ground level and a 2nd TR (Q4) which turns on when the 1st TR (Q2) turns off, cuts off the operating power supply of an output circuit (45) outputting a signal from the output terminals (50), so when the output terminal (50) reaches the ground level or its nearby level, the 1st TR (Q2) turns off and the 2nd TR (Q4) turns on to cut off the operating power supply to the output circuit (45) and then an overcurrent from flowing from the output circuit to the output terminals (50) is prevented, thereby protecting the output circuit (45). |
