Semiconductor circuit device and switching regulator including a level-shifter coupled to a differential amplifier

A semiconductor circuit device that is used for a switching regulator that regulates an input voltage using a switching device and an inductor and outputs an output voltage, the semiconductor circuit device comprising:

• a current detecting circuit that converts an inductor current flowing through the inductor into a voltage and outputs the voltage as a current detection voltage;
• a differential amplifier circuit that includes a MOS transistor provided between a power supply node and an output node and amplifies a difference between a voltage corresponding to the output voltage and a reference voltage;
• a level shifter that level-shifts a voltage at the output node of the differential amplifier circuit to a low potential side and outputs a level-shifted voltage;
• and
• a comparing circuit that compares the current detection voltage with the level-shifted voltage and outputs a switching signal for the switching device, wherein
• the differential amplifier circuit includes
• a first output-stage transistor that is provided between a first power supply node and a first node and outputs a current, and
• a second output-stage transistor that is provided between the first node and the output node and has a gate to which a first bias voltage is input, wherein
• the first power supply node is a low-potential-side power supply node, and
• an amount by which the level shifter level-shifts the voltage at the output node of the differential amplifier circuit is equal to or greater than an overdrive voltage when the first output-stage transistor and the second output-stage transistor operate in a saturated state.