| 摘要 |
PROBLEM TO BE SOLVED: To provide a load drive circuit capable of detecting an open-failure state of a load element during energization control.SOLUTION: An LED 1 of a load circuit 4 is energized from an output terminal OUT of an ECU 2. The ECU 2 is provided with an IC 3. A capacitor 6 is connected between the output terminal OUT and the ground. The IC 3 controls a MOSFET 7 by PWM driving by means of a controller 8. A comparator 11 compares a threshold voltage Vth and an output voltage VL with each other and outputs a detection signal to the controller 8. The controller 8 determines whether or not the output voltage VL is dropped normally when the LED 1 is turned off in a PWM drive state. If the drop is slow, the controller 8 determines an open failure. Thereby, open failures of the load circuit 4 can be determined without a sense of discomfort.SELECTED DRAWING: Figure 1 |
