A power supply circuit relating to the present invention comprises a
differential amplifier for feeding out a voltage as a control voltage in
accordance with a difference between a feedback voltage commensurate with
an output voltage and a reference voltage, an output current control
element for feeding out an output current in accordance with the control
voltage fed thereto from the differential amplifier, an output line by
way of which the output current is supplied to a load, a feedback line by
way of which a voltage on the output line is fed back as the feedback
voltage to the differential amplifier, the feedback line connected to the
output line, and a clamping circuit for maintaining the control voltage
so as not drop below a predetermined value.