CN214013852U

CN214013852U - USB port burnout prevention circuit

Info

Publication number: CN214013852U
Application number: CN202022328280.2U
Authority: CN
Inventors: 马柏杰
Original assignee: SHENZHEN CHINO-E COMMUNICATION CO LTD
Current assignee: SHENZHEN CHINO-E COMMUNICATION CO LTD
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2021-08-20
Anticipated expiration: 2030-10-19

Abstract

The utility model provides a pair of USB mouth prevents burning out circuit, including USB mouth circuit board, its characterized IN that, set up VBUS-IN end and VBUS-CONN end on the USB mouth circuit board, VBUS-IN end is connected with the MOS pipe, the MOS union coupling has error amplifier, the output of MOS pipe with VBUS-CONN end is connected, VBUS-IN end still is connected with first resistance, VBUS-CONN end still is connected with the second resistance, first resistance with error amplifier connects, the second resistance still is connected with the negative temperature coefficient resistance of ground connection. Make because short circuit heavy current or foreign matter cause the heavy current through setting up MOS pipe, error amplifier and NTC, when producing violent heat, the great change step-down can take place for NTC resistance value, makes error amplifier output high level signal, and high level signal closes the MOS pipe, and the disconnection of VBUS route, and normal NTC resistance becomes high when the temperature resumes, and it is normal to charge.

Description

USB port burnout prevention circuit

Technical Field

The utility model belongs to the technical field of the circuit, especially, relate to a USB mouth prevents burning out circuit.

Background

At present, in order to avoid burning out of the USB interface, a PTC resistor is usually placed on the VBUS power line at the USB interface, and when the PTC resistor becomes infinite due to overheating temperature, the VBUS power line is disconnected to cut off the current, so as to avoid generating more heat.

Because the PTC resistor is protected once, the impedance is increased once, the PTC impedance becomes large after frequent protection or multiple protection, the charging efficiency is reduced, the USB port generates heat seriously, and the damage of the USB port caused by heat cannot be better protected.

In summary, there is a need for a method for solving the above-mentioned problems, in which a MOS transistor, an error amplifier and an NTC are arranged such that when a large current is generated due to a short circuit or a large current caused by a foreign object, the resistance of the NTC resistor changes greatly and becomes low, so that the error amplifier outputs a high-level signal, the high-level signal turns off the MOS transistor, the VBUS path is disconnected, and when the temperature returns to a normal value, the NTC resistance becomes high, thereby overcoming the above-mentioned problems.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing prior art's weak point, the utility model aims to provide a USB mouth prevents burning out circuit aims at solving prior art because every protection of PTC resistance is once, and the impedance will the grow once, and frequent protection or protection back PTC impedance can become very big many times, leads to charge efficiency to descend, and the USB mouth generates heat seriously, the unable better problem of protection USB mouth because the damage that the heat caused.

In order to achieve the purpose, the utility model adopts the following technical proposal:

the utility model provides a USB mouth prevents burning out circuit, includes USB mouth circuit board, its characterized IN that, set up VBUS-IN end and VBUS-CONN end on the USB mouth circuit board, VBUS-IN end is connected with the MOS pipe, the MOS union coupling has error amplifier, the output of MOS pipe with VBUS-CONN end is connected, VBUS-IN end still is connected with first resistance, VBUS-CONN end still is connected with the second resistance, first resistance with error amplifier connects, the second resistance still is connected with the negative temperature coefficient resistance of ground connection.

Preferably, the USB port is Type-C or micro-USB.

Preferably, the impedance of the MOS tube is less than 10m omega.

Compared with the prior art, the beneficial effects of the utility model are that:

Drawings

Fig. 1 is a circuit block diagram of the preferred embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the following description of the present invention will refer to the accompanying drawings and illustrate embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

As shown IN the attached drawing 1, the utility model provides a pair of USB mouth prevents burning out circuit, including USB mouth circuit board, its characterized IN that, set up VBUS-IN end and VBUS-CONN end on the USB mouth circuit board, VBUS-IN end is connected with the MOS pipe, the MOS union coupling has error amplifier, the output of MOS pipe with VBUS-CONN end is connected, VBUS-IN end still is connected with first resistance, VBUS-CONN end still is connected with the second resistance, first resistance with error amplifier connects, the second resistance still is connected with the negative temperature coefficient resistance of ground connection.

Specifically, under normal conditions, the error amplifier normally works through the voltage input by the VBUS-IN end, when a USB port is IN short-circuit large current or foreign matter causes large current, when intense heat is generated, the negative temperature coefficient resistor can change greatly to prevent the reduction, so that the error amplifier outputs a high level signal, the MOS tube is closed by the high level signal, a VBUS passage is disconnected, namely, the voltage of the VBUS-CONN is 0, no voltage and current exist at the interface, the heating condition is controlled, when the USB port is not provided with large current any more, after the temperature is recovered, the negative temperature coefficient resistor prevents the high level signal from changing, the error amplifier outputs a low level, at the moment, the MOS tube is normally conducted, the charging is recovered to be normal, and therefore the effect of protecting the circuit is achieved.

In some embodiments, the USB port is a Type-C or micro-USB, and both types of USB ports can be protected.

In some embodiments, the impedance of the MOS transistor is less than 10m Ω.

To sum up, the utility model discloses a theory of operation as follows:

It should be understood that equivalent alterations and modifications can be made by those skilled in the art according to the technical solution of the present invention and the inventive concept thereof, and all such alterations and modifications should fall within the scope of the appended claims.

Claims

1. The utility model provides a USB mouth prevents burning out circuit, includes USB mouth circuit board, its characterized IN that, set up VBUS-IN end and VBUS-CONN end on the USB mouth circuit board, VBUS-IN end is connected with the MOS pipe, the MOS union coupling has error amplifier, the output of MOS pipe with VBUS-CONN end is connected, VBUS-IN end still is connected with first resistance, VBUS-CONN end still is connected with the second resistance, first resistance with error amplifier connects, the second resistance still is connected with the negative temperature coefficient resistance of ground connection.

2. The USB port burnout prevention circuit of claim 1, wherein the USB port is a Type-C or micro-USB.

3. The USB port burnout prevention circuit of claim 1, wherein the MOS transistor has an impedance of less than 10m Ω.