Power supply protection circuit and electronic product

Abstract

The invention discloses a power supply protection circuit and an electronic product. The power supply protection circuit is connected between a voltage output terminal and a power terminal or an enable control terminal of a power supply module and comprises a voltage stabilizing tube, an NPN-type triode and a PNP-type triode; load voltage output by the power supply module is transmitted to the cathode of the voltage stabilizing tube, the anode of the voltage stabilizing tube is connected to a base electrode of the NPN-type triode, an emitting electrode of the NPN-type triode is grounded, and a collector electrode of the NPN-type triode is connected with a base electrode of the PNP-type triode; and the base electrode and an emitting electrode of the PNP-type triode are connected with the power terminal or the enable control terminal of the power supply module, and a collector electrode of the PNP-type triode is connected with the base electrode of the NPN-type triode. According to the power supply protection circuit, two triodes form a base electrode regenerative feedback network, the two triodes can instantly enter a saturated state when a load circuit has an overvoltage or overcurrent fault, and protection action is executed, therefore the protection response speed and the running reliability of the power supply system are greatly improved.

Description

technical field [0001] The invention belongs to the technical field of power supply circuits, and in particular relates to a control circuit for overvoltage and overcurrent protection of a power supply voltage output to a load and an electronic product designed using the power supply protection circuit. Background technique [0002] In the current electronic products, the power supply circuit is an indispensable key component, which is responsible for converting the input voltage into the working voltage required by the subsequent load, and then supplying power to the subsequent load. In order to ensure the power safety of the subsequent load and enhance the reliability of the system operation, most electronic products need to design overvoltage and overcurrent detection circuits on the power supply end of the load, and cut off the load in time when an overvoltage or overcurrent fault occurs power supply to avoid damage to the load. [0003] Take the flat-panel TV product a...

AI Technical Summary

Problems solved by technology

In the existing LED drive control circuit, in order to enhance the reliability of the system, it is necessary to add protection circuits, such as overvoltage and overcurrent protection circuits, to avoid excessive voltage output by the LED drive control unit or flow through the LED. Excessive current causes burning of the LED

For the existing overvoltage and overcurrent protection circuit, its voltage protection circuit and current protection circuit often need to be designed separately and independently, which makes the circuit structure very complicated and bulky

Moreover, most of the existing protection circuits use a control tube (transistor or MOS tube) for control, which greatly reduces the response speed of the system and affects the reliability of the system operation.

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