On-board device

An on-board device installed in a vehicle comprising:

• an input circuit including an input end into which an input voltage is entered;
• and
• a drive power supply circuit that outputs a drive voltage to the input circuit,
• wherein the input circuit includes a PNP bipolar transistor, a pull-up circuit, a second pull-up resistance, and a base resistance,
• wherein the pull-up circuit includes a pull-up power supply, a first pull-up resistance, and a second diode with an anode facing the first pull-up resistance, which are connected in series and are provided between a base of the PNP bipolar transistor and the input end;
• the second pull-up resistance is provided between the base of the PNP bipolar transistor and the drive power supply circuit;
• the base resistance is provided between the base of the PNP bipolar transistor and the second pull-up resistance;
• and
• between a connection point of the second pull-up resistance with the base resistance and the input end, a first diode is interposed with a cathode facing the input end.