| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve protective functions for suitably protecting a circuit from a ground fault or a fault due to short-circuiting. <P>SOLUTION: A load driving circuit 10 includes a first transistor Q1 and a second transistor Q2 as bipolar transistors each connected in series between a first fixed voltage Vdd and a second fixed voltage GND, and supplies a driving current Idrv corresponding to the on/off state of the two transistors to a load connected to an output terminal T1 as a connection point between the two transistors. A current supply 12 controls a base current Ib1 to be supplied to the first transistor Q1. A protective circuit 20 compares an output voltage Vout of the output terminal T1 with a predetermined threshold voltage Vth, and further monitors the on/off state of the first transistor Q1. The protective circuit 20 reduces the base current Ib1 of the first transistor Q1 in a state where Vout<Vth and the first transistor Q1 is an on-state. <P>COPYRIGHT: (C)2008,JPO&INPIT |
