CN211127139U

CN211127139U - Protection circuit for preventing under-voltage protection of electronic product during plugging and unplugging USB

Info

Publication number: CN211127139U
Application number: CN202020069036.6U
Authority: CN
Inventors: 吴李扩; 邹绍见
Original assignee: Zhuhai Gotech Intelligent Technology Co Ltd
Current assignee: Zhuhai Gotech Intelligent Technology Co Ltd
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2020-07-28
Anticipated expiration: 2030-01-13

Abstract

The utility model provides a protection circuit of undervoltage protection when preventing electronic product plug USB locates on the power supply circuit that electronic product carries out the power supply to USB, protection circuit includes chip, first resistance, second resistance, third resistance, first electric capacity, system power supply electric capacity module, first inductance and power output interface, and wherein the third resistance setting is before power output interface. The utility model discloses a concatenate a resistance on the USB power supply line, can improve when inserting the USB device, owing to draw the problem that low electronic product internal system voltage leads to the system to restart, this technical scheme dependable performance, low cost.

Description

Protection circuit for preventing under-voltage protection of electronic product during plugging and unplugging USB

Technical Field

The utility model belongs to the technical field of the protection circuit, especially, relate to an undervoltage protection's protection circuit when preventing electronic product plug USB.

Background

Many electronic products today support an external USB device, and the USB device is powered by the electronic product. When the USB device is plugged in, if the capacitance inside the USB device is large, the system power supply of the electronic product is pulled to a low value, and some protection of the electronic product is triggered, so that the user experience is seriously influenced.

Particularly in the field of set top boxes, due to the fact that market competition is intense, consumption levels are different in different regions, and for low consumption level regions, the cost pressure of low-end set top boxes is higher and higher. In the process of reducing the cost of the low-end set top box, the circuit is simplified, various protection circuits can be deleted, and capacitors with higher cost and the like are used. Eliminating these circuits and capacitors reduces the cost of the set-top box, but also introduces other problems. On the low-end set-top box, a USB device interface supplies power and is directly connected to a 5V system power supply of the set-top box, when the USB device is inserted, if the capacitance inside the USB device is large, the system power supply of the set-top box is pulled to a very low value, the set-top box triggers under-voltage protection to restart, and user experience is seriously influenced.

The current solution on the market is to use a separate USB power management chip, which is generally only used in high-end products for cost reasons. Therefore, it is of great practical interest to find a simple, efficient, low-cost solution.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the not enough of above-mentioned prior art existence, provide an undervoltage protection's protection circuit when preventing electronic product plug USB, through concatenating a resistance on the USB power supply line, when can improving and insert the USB device, owing to draw the problem that the system restarted is leaded to the interior system voltage of low electronic product, this technical scheme dependable performance, low cost.

The utility model provides a protection circuit for preventing under-voltage protection when an electronic product is plugged in and unplugged from a USB, which is arranged on a power supply circuit for supplying power to the USB by the electronic product, it is characterized in that the protection circuit comprises a chip, a first resistor, a second resistor, a third resistor, a first capacitor, a system power supply capacitor module, a first inductor and a power supply output interface, the first capacitor is connected on the chip in parallel, one end of the first inductor is electrically connected with the first capacitor, the other end of the first inductor is connected with the first resistor, the other end of the first resistor is respectively connected with the chip and the second resistor, the other end of the second resistor is grounded, one end of the first resistor connected with the first inductor is also electrically connected with a system power supply capacitor module and a third resistor, the other end of the system power supply capacitor module is grounded, and the other end of the third resistor is connected with a power supply output interface.

Furthermore, the system power supply capacitor module comprises a second capacitor and a third capacitor, the second capacitor and the third capacitor are connected in parallel, one end of the second capacitor is connected with the third resistor after the second capacitor and the third capacitor are connected in parallel, and the other end of the second capacitor is grounded.

Furthermore, the chip is an STI3470 chip, the first capacitor is connected to the BS pin and the L X pin of the chip, respectively, the end of the first inductor electrically connected to the first capacitor is also connected to the L X pin, and the FB pin of the chip is connected to the first resistor and the second resistor, respectively.

The utility model has the advantages that:

the utility model provides an undervoltage protection's protection circuit when preventing electronic product plug USB through concatenating a resistance on the USB power supply line, can improve when inserting the USB device, owing to draw the problem that low electronic product internal system voltage leads to the system to restart, this technical scheme dependable performance, low cost.

Drawings

The present invention is further explained by using the drawings, but the embodiments in the drawings do not constitute any limitation to the present invention, and for those skilled in the art, other drawings can be obtained according to the following drawings without any inventive work.

Fig. 1 is a schematic structural diagram of a protection circuit provided by the present invention.

In the figure: 1-chip; 21-a first resistance; 22-a second resistance; 23-a third resistance; 31-a first capacitance; 32-system power supply capacitance module; 321-a second capacitance; 322-third capacitance; 4-a first inductance; 5-power output interface.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The embodiment provides a protection circuit for preventing under-voltage protection when an electronic product is plugged in or unplugged from a USB, which is arranged on a power supply circuit for supplying power to the USB by the electronic product, the protection circuit is characterized by comprising a chip 1, a first resistor 21, a second resistor 22, a third resistor 23, a first capacitor 31, a system power capacitor module 32, a first inductor 4 and a power output interface 5, wherein the first capacitor 31 is connected on the chip 1 in parallel, one end of the first inductor 4 is electrically connected with the first capacitor 31, the other end of the first inductor is connected with the first resistor 21, the other end of the first resistor 21 is respectively connected with the chip 1 and the second resistor 22, the other end of the second resistor 22 is grounded, the end of the first resistor 21 connected with the first inductor 4 is also electrically connected with the system power supply capacitor module 32 and the third resistor 23, the other end of the system power supply capacitor module 32 is grounded, and the other end of the third resistor 23 is connected to the power output interface 5.

It should be noted that, the third resistor 23 is disposed in front of the power output interface 5, one end of the third resistor is connected to the power output interface 5, the other end of the third resistor is connected to the system power capacitor module 32, the third resistor 23 isolates the system voltage and the USB voltage in the set-top box, when the USB device is inserted, a voltage drop is generated on the third resistor 23 by an instantaneous large current, so as to prevent the system voltage from being pulled very low to cause under-voltage protection, and achieve an effective effect that the set-top box cannot protect restart when the USB device is plugged in or unplugged.

The system power supply capacitor module 32 includes a second capacitor 321 and a third capacitor 322, the second capacitor 321 is connected in parallel with the third capacitor 322, one end of the parallel connection is connected to the third resistor 23, and the other end is grounded.

The system power supply capacitor module 32 is designed into two capacitors, namely a second capacitor 321 and a third capacitor 322, which are connected in parallel and then grounded, so that the power failure condition of the system power supply can be improved by increasing the capacitor at the output end, and the same function of preventing the set top box from being protected and restarted when the USB device is plugged and unplugged is achieved.

Additionally, the chip 1 is an STI3470 chip, the first capacitor 31 is connected to the BS pin and the L X pin of the chip 1, the L X pin is further connected to the end of the first inductor 4 electrically connected to the first capacitor 31, and the FB pin of the chip 1 is connected to the first resistor 21 and the second resistor 22, respectively.

Compared with the prior art, the embodiment provides a protection circuit for preventing undervoltage protection when an electronic product is plugged in or unplugged from a USB, and the problem of system restart caused by pulling down the system voltage in the electronic product when a USB device is plugged in can be solved by connecting a resistor in series on a USB power supply line.

Finally, it should be emphasized that the present invention is not limited to the above-described embodiments, but only to the preferred embodiments of the invention, and is not limited to the embodiments, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included within the scope of the present invention.

Claims

1. The utility model provides a protection circuit of undervoltage protection when preventing electronic product plug USB, locates on the power supply circuit that electronic product carries out the power supply to USB, its characterized in that, protection circuit includes chip, first resistance, second resistance, third resistance, first electric capacity, system power supply capacitance module, first inductance and power output interface, first electric capacity is parallelly connected on the chip, first inductance one end is connected with this first electric capacity electricity, the other end with first resistance connection, the first resistance other end is connected respectively chip and second resistance, the other end ground connection of this second resistance, system power supply capacitance module and third resistance are still electrically connected to first resistance one end of being connected with this first inductance, and the ground connection of this system power supply capacitance module other end, power output interface are connected to this third resistance other end.

2. The protection circuit of claim 1, wherein the system power supply capacitor module comprises a second capacitor and a third capacitor, the second capacitor and the third capacitor are connected in parallel, one end of the second capacitor is connected to the third resistor, and the other end of the second capacitor is grounded.

3. The protection circuit of claim 1, wherein the chip is an STI3470 chip, the first capacitor is connected to the BS pin and the L X pin of the chip, respectively, the end of the first inductor electrically connected to the first capacitor is also connected to the L X pin, and the FB pin of the chip is connected to the first resistor and the second resistor, respectively.