CN210577787U

CN210577787U - Protection circuit supporting hot plug and impact prevention

Info

Publication number: CN210577787U
Application number: CN201921435787.9U
Authority: CN
Inventors: 刘雷礼
Original assignee: Nanjing Vishee Medical Technology Co Ltd
Current assignee: Nanjing Vishee Medical Technology Co Ltd
Priority date: 2019-08-31
Filing date: 2019-08-31
Publication date: 2020-05-19
Anticipated expiration: 2029-08-31

Abstract

The utility model discloses a protection circuit supporting hot plug and impact resistance, which comprises a primary protection unit and a secondary protection unit; the primary protection unit comprises an MOS tube protection circuit, a capacitor charging and discharging circuit and an MOS tube current control circuit; the secondary protection unit comprises a transient absorption diode D2 and a voltage stabilizing diode D3 which are connected between VOUT and GND. The utility model discloses can effectively play the effect of protection to the impact that the back level circuit formed in the twinkling of an eye on the system.

Description

Protection circuit supporting hot plug and impact prevention

Technical Field

The utility model relates to a protecting circuit against shock, a concretely designs support hot plug protecting circuit against shock belongs to circuit technical field.

Background

With the development of science and technology, in electronic devices, a control system is generally composed of electronic components with a "control" function, which are composed of circuits and the like, and in the circuits of the control system, various electronic components with logic functions respectively play their own roles and cooperate with each other in a unified manner to complete a control process. It should be noted here that all the electronic components transmit electric signals, and the withstand voltage, the withstand current, and the impact resistance of the electronic components are different from each other. However, in the electronic device, due to the existence of the capacitor, the system generates a large current instantly when the switch is turned on; transient high voltage exceeding the voltage of the battery can be generated when a large-current connector is plugged; when the high-current connector is subjected to hot plugging, sparks are easy to generate, and influence is caused on electronic components and production.

In summary, no effective solution exists for the problem that a control system and the electronic device are adversely affected by a large voltage surge generated by hot plugging during the operation of the electronic device.

In view of the above, there is a need for further research into surge protection circuits.

Disclosure of Invention

For solving the not enough of prior art, the utility model aims to design a support hot plug protecting against shock circuit, provide a protecting against shock duplicate protection circuit that is practical feasible, simple structure, low cost, convenient to use.

In order to achieve the above object, the utility model adopts the following technical scheme:

a protection circuit supporting hot plug and impact prevention comprises a primary protection unit and a secondary protection unit;

the primary protection unit comprises an MOS tube protection circuit, a capacitor charging and discharging circuit and an MOS tube current control circuit;

the secondary protection unit comprises a transient absorption diode D2 and a voltage stabilizing diode D3 which are connected between VOUT and GND.

Further, the MOS tube protection circuit comprises a voltage stabilizing diode D1, a resistor R1, a capacitor C1 and a PMOS tube Q1 which are connected in parallel.

The capacitor charging and discharging circuit comprises a resistor R3, a resistor R5, a capacitor C2 and a resistor R6 which is connected with the capacitor C2 in parallel.

The MOS tube current control circuit comprises an NPN type triode Q2, a resistor R4 and a resistor R2 which are connected in series.

Furthermore, the base B and the emitter E of the NPN transistor Q2 are connected in parallel to the capacitor C2, and the resistors R3 and R5 are connected in series to the base B and the emitter E of the NPN transistor Q2.

In addition, the secondary protection unit includes a transient absorption diode D2 and a zener diode D3 connected in parallel and respectively connected to the ground terminal and the output terminal of the PMOS transistor Q1.

The PMOS transistor Q1 is connected to the VIN input terminal, the VOUT output terminal, and the output terminal of the resistor R2, respectively.

The utility model discloses the effect that reaches:

i) the transient impact protection of the later stage is realized;

ii) further enhancing the reliability and stability of the system;

iii) the circuit is more stable and reliable in actual operation.

Drawings

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

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.

The protection circuit supporting hot plug and impact prevention comprises a primary protection unit and a secondary protection unit; the primary protection unit comprises an MOS tube protection circuit, a capacitor charging and discharging circuit and an MOS tube current control circuit; the secondary protection unit comprises a transient absorption diode D2 and a voltage stabilizing diode D3 which are connected between VOUT and GND.

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

As shown in fig. 1: the specific circuit is as follows: the MOS tube protection circuit comprises a voltage-stabilizing diode D1, a resistor R1, a capacitor C1 and a PMOS tube Q1 which are connected in parallel. The capacitor charging and discharging circuit comprises a resistor R3, a resistor R5, a capacitor C2 and a resistor R6 which is connected with the capacitor C2 in parallel. The MOS tube current control circuit comprises an NPN type triode Q2, a resistor R4 and a resistor R2 which are connected in series.

The input end of the current is respectively connected with a resistor R3, a zener diode D1, a resistor R1, a capacitor C2 and a PMOS tube Q1, the other end of the resistor R3 is connected with a resistor R5, the other end of the resistor R5 is connected with a capacitor C2, the capacitor C2 is connected with a resistor R6 and an NPN type triode Q2 in parallel, the capacitor C2 is grounded with the resistor R2 and the NPN type triode Q2 at the same time, the zener diode D2 is connected with the resistor R2 and the capacitor C2 in parallel, the output ends of the zener diode D2, the resistor R2 and the capacitor C2 are the output end of the resistor R2 and the input end of the resistor R2, the resistor R2 is connected with the resistor R2, the NPN type triode Q2 is connected with the PMOS tube Q2 in series, and the output end of the VOUT is connected with. The transient absorption diode D2 and the voltage stabilizing diode D3 are connected in parallel, one end of the transient absorption diode is grounded, and the other end of the transient absorption diode is connected with the output end of VOUT.

At the moment of system power-on of the circuit, due to the existence of the MOS transistor Q1, the NPN type triode Q2, the resistor R3, the resistor R5, the capacitor C2 and the resistor R6, the voltage input end VIN cannot reach the voltage output end VOUT through Q1 completely, and therefore impact on a rear-stage circuit is prevented.

At the moment of system power-on, because an NPN type triode Q2 with a capacitor C2 cannot be completely conducted immediately, a voltage input end VIN charges a capacitor C2 through a resistor R3 and a resistor R5, the NPN type triode Q2 is slowly conducted in the process of charging the capacitor C2, the resistor R6 and the capacitor C2 are connected in parallel with an NPN type triode Q2 for protection, only when the voltage of the capacitor C2 is charged to 0.7V, the NPN type triode Q2 is completely conducted, at the moment, an MOS (metal oxide semiconductor) tube Q1 is completely conducted, the voltage is input through the voltage input end VIN and reaches a voltage output end VOUT through a PMOS tube Q1, and the resistors R2 and R4 play a further protection role; the utility model realizes the transient impact protection of the rear stage by controlling the conduction time of the PMOS tube Q1; meanwhile, a transient absorption diode D2 and a voltage stabilizing diode D3 are connected between the voltage output end VOUT and the ground wire end GND to further enhance the reliability and stability of the system; in addition, a voltage stabilizing diode D1 in the circuit can also prevent the damage of a PMOS tube caused by instantaneous high voltage, so that the circuit is more stable and reliable in actual operation.

In conclusion, the circuit can well protect a rear-stage circuit at the moment of system power-on, and the key point is that the NPN type triode Q2 is slowly conducted in the charging process of the capacitor C2, so that impact formed when the circuit is subjected to hot plugging is prevented.

As mentioned above, although the present invention has been shown and described with reference to certain preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A protection circuit supporting hot plug and impact prevention is characterized by comprising a primary protection unit and a secondary protection unit;

2. The protection circuit supporting hot plug and shock protection as claimed in claim 1, wherein the MOS transistor protection circuit comprises a zener diode D1, a resistor R1, a capacitor C1 and a PMOS transistor Q1 connected in parallel.

3. The circuit for supporting hot plug and shock protection as claimed in claim 2, wherein the capacitor charging and discharging circuit comprises a resistor R3, a resistor R5, a capacitor C2 and a resistor R6 connected in parallel with the capacitor C2.

4. A hot plug-enabled anti-shock protection circuit as claimed in claim 3, wherein said MOS transistor current control circuit comprises an NPN transistor Q2, a resistor R4 and a resistor R2 connected in series.

5. A hot plug-supporting anti-shock protection circuit as claimed in claim 4, wherein the base B and the emitter E of said NPN transistor Q2 are connected in parallel with said capacitor C2, and said resistors R3 and R5 are connected in series with the base B and the emitter E of said NPN transistor Q2.

6. The circuit of claim 1, wherein the secondary protection unit comprises a transient absorption diode D2 and a zener diode D3 connected in parallel and respectively connected to the ground terminal and the output terminal of the PMOS transistor Q1.

7. The circuit of claim 6, wherein the PMOS transistor Q1 is connected to the VIN input terminal, the VOUT output terminal and the output terminal of the resistor R2, respectively.