CPC H02M 1/0003 (2021.05) [H02M 3/33523 (2013.01)] | 12 Claims |
1. An integrated circuit for a power supply circuit that generates an output voltage at a target level from an input voltage inputted thereto, the power supply circuit including
a transformer including a primary coil, a secondary coil, and an auxiliary coil, and
a transistor configured to control a current flowing through the primary coil,
the integrated circuit being configured to drive the transistor, the integrated circuit comprising:
a first terminal configured to receive a voltage corresponding to a coil voltage across the auxiliary coil when the transistor is off;
a second terminal configured to receive a feedback voltage corresponding to the output voltage;
a third terminal configured to receive a voltage, which
corresponds to a current flowing through the transistor when the transistor is on, and
corresponds to the coil voltage when the transistor is off;
a first detection circuit configured to detect whether the voltage at the third terminal when the transistor is off is lower than a first reference voltage; and
a control circuit configured to control switching of the transistor based on the feedback voltage, the voltage at the third terminal when the transistor is on, and a result of detection of the first detection circuit.
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