Power supply input circuit and inverter-integrated vehicular electric compressor equipped with same

A power input circuit that includes a power switching element connected between a DC power supply and a load and that controls a current from the DC power supply to the load by changing a voltage of a control electrode of the power switching element, the power input circuit comprising:

• a current detection resistor in which a voltage is induced at both ends by an inrush current;
• and
• a current limiting switching element having a control electrode and a pair of main electrodes, one main electrode being connected to the control electrode of the power switching element, wherein
• in the current limiting switching element, a voltage of the control electrode of the current limiting switching element changes in response to a voltage induced across the current detection resistor, the voltage of the control electrode of the power switching element is adjusted to perform a constant current operation, and
• a negative temperature coefficient thermistor is connected between the control electrode and the other main electrode of the current limiting switching element.