CN212210482U

CN212210482U - USB electrostatic protection circuit on WIFI module

Info

Publication number: CN212210482U
Application number: CN202020931090.7U
Authority: CN
Inventors: 周露; 陈鹏; 邓勇才
Original assignee: China Dragon Technology Co ltd
Current assignee: China Dragon Technology Co ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2020-12-22
Anticipated expiration: 2030-05-27

Abstract

The utility model is suitable for an electrostatic protection field provides a USB electrostatic protection circuit on WIFI module, USB electrostatic protection circuit includes ESD protecting tube D1, ESD protecting tube D2, inductance L1 and inductance L2, the DM wiring end of USB interface is connected respectively to ESD protecting tube D1's 1 wiring end reaches inductance L1's one end, the DP wiring end that the USB interface was connected respectively to ESD protecting tube D2's 1 wiring end reaches inductance L2's one end, USB D-signal end is connected to inductance L1's the other end, USB D + signal end is connected to inductance L2's the other end, ESD protecting tube D1's 2 wiring ends reaches GND is all connected to ESD protecting tube D2's 2 wiring ends. The technical problems that a USB electrostatic protection circuit in the prior art is too complex and high in cost, and the USB signal distortion is easily caused due to the fact that the ground capacitance is too large are solved.

Description

USB electrostatic protection circuit on WIFI module

Technical Field

The utility model belongs to the electrostatic protection field especially relates to a USB electrostatic protection circuit on WIFI module.

Background

With the development of the WIFI technology, some products such as televisions, set-top boxes and IPCs can use a WIFI module for USB2.0 communication; in the traditional USB electrostatic protection, TVS tubes, capacitors and common-mode inductors are added to VDD and signal lines D +/D-to-ground for protection, the design scheme can effectively inhibit static from interfering through USB data lines, but the cost is too high, and the USB signal distortion is easily caused by the overlarge capacitance to ground; moreover, the conventional USB electrostatic protection circuit is too complex, and the cost of the WIFI module which does not need too high electrostatic protection is invisibly increased; and the module is small in size and is not suitable for adopting a complex electrostatic protection circuit.

Disclosure of Invention

An object of the utility model is to provide a USB electrostatic protection circuit on various WIFI modules, it is too complicated to aim at the USB electrostatic protection circuit who solves among the prior art, and is with high costs to the too big technical problem who causes USB signal distortion easily of earth capacitance.

The utility model discloses a realize like this, a USB electrostatic protection circuit on WIFI module, USB electrostatic protection circuit includes ESD protecting tube D1, ESD protecting tube D2, inductance L1 and inductance L2, the DM wiring end that the USB interface was connected respectively to ESD protecting tube D1's 1 wiring end reaches inductance L1's one end, the DP wiring end that the USB interface was connected respectively to ESD protecting tube D2 reaches inductance L2's one end, USB D-signal end is connected to inductance L1's the other end, USB D + signal end is connected to inductance L2's the other end, ESD protecting tube D1's 2 wiring ends reaches GND is all connected to ESD protecting tube D2's 2 wiring ends.

The utility model discloses a further technical scheme is: the ESD protective tube D1 and the ESD protective tube D2 are both 1-3pF junction capacitance ESD protective tubes.

The utility model discloses a further technical scheme is: the inductor L1 and the inductor L2 are both 18nH inductors.

The utility model discloses a further technical scheme is: the USB interface is a USB2.0 interface.

The utility model has the advantages that: the anti-static protection circuit designed by using the ESD protective tube and the inductor has simple design, low cost and practicability, and the junction capacitance of the ESD protective tube is small, so that the high-speed transmission of the USB2.0 is not influenced; compared with a universal USB2.0 anti-static circuit, the circuit is simpler, the material is less, the influence of junction capacitance of an ESD device on a USB signal is avoided while the ESD protection is emphasized, the electromagnetic interference generated when the static electricity is solved by the inductor in the circuit, the circuit is more suitable for being applied to a WIFI module, the circuit structure is simple, the PCB space is not occupied, and the material cost is reduced while the electrostatic protection requirement is met.

Drawings

Fig. 1 is an electrical schematic diagram of a USB electrostatic protection circuit on a WIFI module provided by the embodiment of the present invention.

Detailed Description

Fig. 1 shows a pair of USB electrostatic protection circuit on WIFI module, USB electrostatic protection circuit includes ESD protective tube D1, ESD protective tube D2, inductance L1 and inductance L2, the DM wiring end of USB interface is connected respectively to 1 wiring end of ESD protective tube D1 and inductance L1's one end, the DP wiring end of USB interface is connected respectively to 1 wiring end of ESD protective tube D2 and inductance L2's one end, USB D-signal end is connected to inductance L1's the other end, USB D + signal end is connected to inductance L2's the other end, ESD protective tube D1's 2 wiring end and ESD protective tube D2's 2 wiring end all connects GND.

The ESD protective tube D1 and the ESD protective tube D2 are both 1-3pF junction capacitance ESD protective tubes. The inductor L1 and the inductor L2 are both 18nH inductors. The USB interface is a USB2.0 interface.

The 1 terminal of the ESD protective tube D1/D2 is respectively connected with DM/DP of the USB2.0 interface, and the 2 terminal is connected with GND; the inductor L1/L2 is close to the ESD protection tube to connect the D-/D + of the WIFI chip and the DM/DP of the USB interface in series, and the ESD protection tube D1/D2 in the circuit can effectively inhibit charge injection generated by static electricity, thereby playing a static electricity discharge function and leading the static electricity into the ground quickly to achieve the purpose of static electricity protection; the inductor L1/L2 can effectively inhibit the electromagnetic interference effect generated by the electrostatic discharge current and can also play a certain role in inhibiting static electricity; it should be noted that the ESD protection tube D1/D2 and the inductor L1/L2 in the circuit need to be placed close to the USB interface to effectively play a role in protection; in addition, the ESD protective tube D1/D2 needs to be a junction capacitance ESD protective tube with the capacitance of less than 3pF, and the USB signal distortion is easily caused by overlarge capacitance;

the anti-static protection circuit designed by using the ESD protective tube and the inductor has simple design, low cost and practicability, and the junction capacitance of the ESD protective tube is small, so that the high-speed transmission of the USB2.0 is not influenced; compared with a universal USB2.0 anti-static circuit, the circuit is simpler, the material is less, the influence of junction capacitance of an ESD device on a USB signal is avoided while the ESD protection is emphasized, the electromagnetic interference generated when the static electricity is solved by the inductor in the circuit, the circuit is more suitable for being applied to a WIFI module, the circuit structure is simple, the PCB space is not occupied, and the material cost is reduced while the electrostatic protection requirement is met.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a USB electrostatic protection circuit on WIFI module which characterized in that: the USB electrostatic protection circuit comprises an ESD protection tube D1, an ESD protection tube D2, an inductor L1 and an inductor L2, a terminal 1 of the ESD protection tube D1 is connected with a DM terminal of a USB interface and one end of the inductor L1 respectively, a terminal 1 of the ESD protection tube D2 is connected with a DP terminal of the USB interface and one end of the inductor L2 respectively, the other end of the inductor L1 is connected with a USB D-signal end, the other end of the inductor L2 is connected with a USB D + signal end, and a terminal 2 of the ESD protection tube D1 and a terminal 2 of the ESD protection tube D2 are connected with GND respectively.

2. The USB ESD protection circuit of claim 1, wherein the ESD protection tube D1 and the ESD protection tube D2 are both 1-3pF junction capacitance ESD protection tubes.

3. The USB ESD protection circuit of claim 2, wherein the inductor L1 and the inductor L2 are both 18nH inductors.

4. The USB ESD protection circuit of claim 3, wherein the USB interface is a USB2.0 interface.