Current-limiting protection circuit based on IO port control

Abstract

The utility model relates to a current-limiting protection circuit based on IO port control. The current-limiting protection circuit comprises resistors RN1, RN2, RN3 and RN4, capacitors CN1, CN2 and CN3, an electrolytic capacitor E1 and a current-limiting protection chip UN1. One end of the resistor RN1 is connected with the GND, and the other end of the resistor RN1 is connected with the current-limiting protection chip UN1; one end of the resistor RN2 is connected with the 12VOUT, and the other end of the resistor RN2 is connected with the GND; and one end of the resistor RN3 is connected with 12V, and the other end of the resistor RN3 is connected with the IOPLCPowerCt1. The device is reasonable in design, compact in structure and convenient to use.

Description

Technical Field

[0001] The utility model relates to a current limiting protection circuit based on IO port control, belonging to the field of circuits. Background Art

[0002] With the popularity of smart meters overseas, more and more meters are equipped with modules, such as GPRS modules, 3G modules, 4G modules, NB modules, PLC modules, etc. If a module is short-circuited or damaged on site, it may cause the meter to reset or not work, thus affecting the meter's measurement. The MP5036 current limiting chip is mainly used to solve various safety issues related to current management in electronic systems, ensuring that the system can maintain safe and stable operation under various working conditions and extending the service life of each component.

[0003] In electronic systems, load current may exceed the design value due to faults or emergencies, causing device damage or system crash. As a chip with built-in current limiting function, MP5036 can quickly limit the current when it detects that the output current exceeds the preset value to prevent excessive current from passing through the load, thereby playing a protective role. When a short circuit occurs at the load end, if there is no proper protection, a large current will flow directly through the power path, generating a lot of heat and possibly damaging the power supply device and other related components. MP5036 has short-circuit detection and protection functions, which can cut off or limit the current output in a short time to avoid the potential risks caused by short circuits. Utility Model Content

[0004] The technical problem to be solved by the utility model is generally to provide a current limiting protection circuit based on IO port control. Through the utility model, whether the current limiting protection chip UN1 is working can be controlled through the GPIO port. If a short circuit occurs in the module, the current limiting protection chip UN1 directly cuts off the power supply without affecting the meter product.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is:

[0006] In order to realize circuit protection, a current limiting protection circuit based on IO port control includes resistors RN1, RN2, RN3, RN4, capacitors CN1, CN2, CN3, electrolytic capacitor E1 and current limiting protection chip UN1;

[0007] One end of resistor RN1 is connected to GND, and the other end is connected to current limiting protection chip UN1; one end of resistor RN2 is connected to 12V_OUT, and the other end is connected to GND; one end of resistor RN3 is connected to 12V, and the other end is connected to IO_PLCPower_Ct1; one end of resistor RN4 is connected to IO_PLCPower_Ct1, and the other end is connected to GND;

[0008] One end of capacitor CN1 is connected to 12V_OUT, and the other end is connected to GND; one end of capacitor CN2 is connected to 12V, and the other end is connected to GND; one end of capacitor CN3 is connected to pin 6 of current limiting protection chip UN1, and the other end is connected to GND;

[0009] Electrolytic capacitor E1, one end is connected to 12V_OUT, and the other end is connected to GND.

[0010] The beneficial effects of the utility model are as follows: 1. It is safe, reliable and easy to use; 2. It has simple circuits, low cost, high sensitivity, strong adaptability and practicality; 3. The power supply of the module can be controlled through GPIO to realize remote opening and closing of the module power supply; 4. If an abnormality occurs in the module, the power supply can be cut off to protect the meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the use structure of the current limiting protection circuit of the utility model.

[0012] Figure 2 It is a partial pin diagram of the MP5036 current limiting chip of the utility model.

[0013] Figure 3 It is a schematic diagram of the structure of the voltage stabilizer of the utility model.

[0014] Figure 4 It is a communication flow chart of the utility model. DETAILED DESCRIPTION

[0015] The present invention is fully described for a clearer disclosure, and the prior art will not be listed one by one.

[0016] like Figure 1-4 As shown, a current limiting protection circuit based on IO port control of this embodiment is applicable to the MP5036 current limiting chip, which includes resistors RN1, RN2, RN3, RN4, capacitors CN1, CN2, CN3, electrolytic capacitor E1 and current limiting protection chip UN1;

[0017] One end of resistor RN1 is connected to GND, and the other end is connected to current limiting protection chip UN1; one end of resistor RN2 is connected to 12V_OUT, and the other end is connected to GND; one end of resistor RN3 is connected to 12V, and the other end is connected to IO_PLCPower_Ct1; one end of resistor RN4 is connected to IO_PLCPower_Ct1, and the other end is connected to GND;

[0018] One end of capacitor CN1 is connected to 12V_OUT, and the other end is connected to GND; one end of capacitor CN2 is connected to 12V, and the other end is connected to GND; one end of capacitor CN3 is connected to pin 6 of current limiting protection chip UN1, and the other end is connected to GND;

[0019] Electrolytic capacitor E1, one end is connected to 12V_OUT, and the other end is connected to GND.

[0020] Resistor RN1 is the current limiting resistor of the current limiting protection chip UN1. MP5036 provides constant current limit, and the current limit can be programmed by external resistors. Ilimit=0.37*3840 / RN1. Capacitor CN2 is the filter decoupling capacitor of the current limiting protection chip UN1, connected to pin 5 of the current limiting chip. Pin 5 of the current limiting chip is the VIN pin, the power supply voltage input pin, which can be input from 2.9V to 14V.

[0021] The input power supply is decoupled through a ceramic capacitor. Capacitor CN3 is connected to pin 6 of the current limiting protection chip UN1 to set the DV / DT conversion rate. When the DV / DT pin is floating, the DV / DT conversion rate is 2V / ms.

[0022] When there is an external DV / DT capacitor, the DV / DT conversion efficiency can be calculated by the formula DV / DT (V / ms) = 6.5uA*15 / C (nF). And the conversion efficiency of DV / DT affects the soft start time. The specific formula is as follows: T_ss (ms) = Vin / (DV / DT). RN3 and RN4 are the enable resistors of the current limiting protection chip UN1. Through the 12V power supply voltage division, the voltage enters the EN pin. The enable voltage turn-on threshold of the EN pin is 1.86V~2.16V, and the rated value is 2V. The enable voltage turn-off threshold of the EN pin is 1.51V~1.81V. Design the voltage divider resistor according to the turn-on and turn-off thresholds. A 5.5V Zener diode is used inside the EN pin. Even if the designed voltage exceeds 5.5V, it will be clamped to 5.5V by the Zener diode after entering the EN pin, but it is necessary to control the EN input current line below 100uA to prevent damage to the Zener diode. However, this is a pure hardware method to turn on or off the current limiting protection chip UN1. If the module cannot be reset by soft reset on site, it is necessary to reset the power supply to hard reset the module. At this time, IO_PLCPower_Ct1 can output a low level to reset the current limiting protection chip UN1, thereby achieving a hard reset of the module. Capacitor CN1, electrolytic capacitor E1, and resistor RN2 are all connected to the SOURCE pin and GND of the current limiting protection chip UN1. The SOURCE of the current limiting protection chip UN1 is the source of the internal MOS tube and the output pin of the current limiting protection chip UN1.

[0023] Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein.

Claims

1. A current limiting protection circuit based on IO port control, characterized in that: Including resistors RN1, RN2, RN3, RN4, capacitors CN1, CN2, CN3, electrolytic capacitor E1 and current limiting protection chip UN1; One end of resistor RN1 is connected to GND, and the other end is connected to current limiting protection chip UN1; one end of resistor RN2 is connected to 12V_OUT, and the other end is connected to GND; one end of resistor RN3 is connected to 12V, and the other end is connected to IO_PLCPower_Ct1; one end of resistor RN4 is connected to IO_PLCPower_Ct1, and the other end is connected to GND; One end of capacitor CN1 is connected to 12V_OUT, and the other end is connected to GND; one end of capacitor CN2 is connected to 12V, and the other end is connected to GND; one end of capacitor CN3 is connected to pin 6 of current limiting protection chip UN1, and the other end is connected to GND; Electrolytic capacitor E1, one end is connected to 12V_OUT, and the other end is connected to GND.

2. The current limiting protection circuit based on IO port control according to claim 1, characterized in that: The current limiting protection chip UN1 is based on the MP5036 current limiting chip.

3. The current limiting protection circuit based on IO port control according to claim 1, characterized in that: Resistor RN1 is a current limiting resistor.

4. The current limiting protection circuit based on IO port control according to claim 3 is characterized in that: Capacitor CN2 is a filtering decoupling capacitor, which is connected to pin 5 of the current limiting protection chip UN1; pin 5 of the current limiting protection chip UN1 is the VIN pin, which is the power supply voltage input pin.

5. The current limiting protection circuit based on IO port control according to claim 3, characterized in that: Capacitor CN3 is used to set the conversion rate of DV / DT. When the DV / DT pin is floating, the DV / DT conversion rate is 2V / ms.

6. The current limiting protection circuit based on IO port control according to claim 3, characterized in that: The resistors RN3 and RN4 are enable resistors of the current limiting protection chip UN1.

7. The current limiting protection circuit based on IO port control according to claim 3, characterized in that: The SOURCE of the current limiting protection chip UN1 is the source of the internal MOS tube and is the output pin of the current limiting protection chip UN1.

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