Circuit for controlling switching power supply by current limiting and magnetic field detection, and method for controlling switching power supply by using circuit

摘要

A circuit for controlling a switching power supply and a method for controlling a switching power supply by using the circuit for controlling the switching power supply, the circuit for controlling a switching power supply is configured to control a power stage circuit of a converter of the switching power supply. The circuit for controlling the switching power supply includes an external magnetic field direct detection unit, a current limit threshold unit, an operating frequency unit, a pulse width unit and a logic unit. The external magnetic field direct detection unit includes a Hall device and a Hall detection component. In accordance with the circuit for controlling the switching power supply of the present disclosure, the intensity of the external magnetic field can be detected directly at the chip level, and the operating mode of the switching power supply system can be adjusted timely.