Over-current protection circuit based on pulse width modulation and operation method thereof

Abstract

The invention relates to an overcurrent protection circuit based on pulse width modulation and an operation method thereof, the overcurrent protection circuit comprises a pulse width modulation circuit, a charge pump and a load detection circuit, the charge pump is connected with a power switch circuit, and the charge pump outputs voltage to the power switch circuit according to a frequency voltage signal. The load detection circuit can detect the overcurrent passing through the power switch circuit according to the load of the power switch circuit at the output end. Therefore, when the load detection circuit detects overcurrent, the pulse width modulation circuit controls the work cycle width of the charge pump to suppress the voltage output by the charge pump, so that the output voltage of the power switch circuit is corrected, and the overcurrent can be avoided or reduced.

Description

technical field [0001] The application of the present invention discloses an overcurrent protection scheme, in particular a protection circuit and its operation method for suppressing overcurrent in a power supply control circuit by using pulse width modulation technology. Background technique [0002] It is common for electronic devices to design an overcurrent protection circuit in the power supply circuit to clamp the current to a certain current level. The purpose is to suppress the excessive current in the circuit and avoid the problem of damage caused by large current passing through the components. It has protection function of the circuit. [0003] Can refer to figure 1 It shows the schematic diagram of the power switch circuit set in the circuit system, taking the control circuit of USB Type-C as an example, wherein the power switch circuit 10 is responsible for controlling the power supply terminal (VCONN) from the source terminal (source) to The magnitude of the...

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Problems solved by technology

[0008] In view of the fact that the existing over-current protection measures cannot solve all the problems, for example, the way of suppressing the over-current by using the burst mode will cause ripples on the voltage terminal because the energy transmitted each time is too large, the application of the present invention proposes a pulse-based The width-modulated overcurrent protection circuit and its operation method propose a method of adjusting the pulse width of the duty cycle of the current pump in the circuit to modulate the current passing through the power switch. Can effectively suppress overcurrent and avoid output voltage ripple

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