Drive circuit of high-side transistor, switching circuit, and controller of DC/DC converter

The present disclosure relates to a high-side transistor drive circuit, a switching circuit and a controller of a DC/DC converter. A pulse generator generates a first pulse that becomes high level for a certain period of time in response to a first edge of an input signal and a second pulse that becomes high level for a certain period of time in response to a second edge of the input signal. An open drain circuit has a first output node that becomes low level in response to the first pulse and a second output node that becomes low level in response to the second pulse. A first current mirror circuit folds back a first current flowing through the first output node of the open drain circuit. A second current mirror circuit folds back a second current flowing through the second output node of the open drain circuit.