| 摘要 |
<p>PURPOSE: To decrease loss of an overvoltage processing circuit by providing an IC group for directly inputting the voltage generated from a vehicle alternator as a power supply voltage of internal IC of an electronic control device for a vehicle to be taken as the power supply voltage, and an IC group for taking the same as the power supply voltage through the overvoltage processing circuit. CONSTITUTION: An electronic control device 6 for a vehicle inputs the voltage from an alternator 1 having an overvoltage processing means and the voltage of a battery 2 as the power supply voltage 20. The power supply voltage 20 is input to an overvoltage processing circuit 4 for preventing the input of power supply voltage of the IC group 3 and the overvoltage to the IC group 5. The overvoltage processing means of the alternator 1 is a constant-voltage diode with Zener voltage of 36V, and holds down the overvoltage such as the surge voltage or the like to 36V, so that the power supply voltage 20 to the electronic control device 6 for a vehicle is 36V or less. The IC group 3 is IC with the absolute maximum rating power supply voltage of 36V or more. On the other hand, the IC group 5 is IC with the absolute maximum rating power supply voltage of 36V or less, and the overvoltage processing circuit 4 is disposed not to exceed the absolute maximum rating power supply voltage.</p> |
