Switching control circuit

摘要

A switching-control circuit to control switching of a transistor whose input electrode is applied with an input voltage, and turn off the transistor, when an output current from the transistor is greater than a reference current, includes: a reference-voltage-generating circuit to generate such a first-reference voltage that the reference current is reduced with reduction in an output voltage; a comparing circuit to compare a voltage corresponding to the output current with the first-reference voltage; and a driving circuit to turn on/off the transistor based on a feedback voltage corresponding to the output voltage and a second reference voltage corresponding to a target level so that the output voltage reaches the target level, when the comparing circuit determines that the output current is smaller than the reference current, and turn off the transistor when the comparing circuit determines that the output current is greater than the reference current.

主权项

1. A switching control circuit configured to control switching of a transistor whose input electrode is applied with an input voltage, and turn off the transistor, when an output current from the transistor is greater than a reference current, in order to generate an output voltage of a target level from the input voltage, the switching control circuit comprising:
a reference voltage generating circuit configured to generate such a first reference voltage that the reference current is reduced with reduction in the output voltage; a comparing circuit configured to compare a voltage corresponding to the output current with the first reference voltage; and a driving circuit configured to
turn on/off the transistor based on a feedback voltage corresponding to the output voltage and a second reference voltage corresponding to the target level so that the output voltage reaches the target level, when the comparing circuit determines that the output current is smaller than the reference current, andturn off the transistor when the comparing circuit determines that the output current is greater than the reference current.