CN206506290U - A hot swap protection circuit - Google Patents

Abstract

The utility model discloses a kind of hot plug protection circuit, belong to circuit protection technology field.It includes data wire protection circuit and power protecting circuit; wherein; data wire protection circuit includes pull-up resistor, neck and electromagnetic interface filter; described pull-up resistor one end connects the power supply of electromagnetic interface filter; input and the data line terminal connection of the pull-up resistor other end and electromagnetic interface filter; the output end of electromagnetic interface filter is connected with neck; described power protecting circuit includes flash power switch and TVS diode; flash power switch input is connected with power supply terminal, is connected after output end is in parallel with TVS diode with neck.The data wire of chip passes through pull-up resistor and electromagnetic interface filter compound action; play a part of preventing over-voltage and over-current and overheat; chip internal structure performance is protected, by flash power switch and TVS diode collective effect in power protecting circuit, the effect of protection chip is played.

Description

A hot swap protection circuit

technical field

The utility model relates to the technical field of circuit protection, in particular to a hot plug protection circuit.

Background technique

Hot swap (Hot Swap) refers to inserting or removing a circuit board in a live running backplane. This technology is suitable for use in systems with a backplane bus (the system has multiple plug-ins, and the power and part of the signals of each plug-in are connected together). Its main feature is to replace the faulty circuit board while maintaining the voltage of the system backplane, and to ensure the normal operation of other circuits in the system. The advantage is that it facilitates the upgrade and maintenance of system hardware, shortens the time for system failure analysis; avoids the failure caused by plugging and unplugging circuit boards when the system is powered off, and reduces maintenance costs.

During the hot-swapping process of SD cards, SIM cards, or single boards, static electricity and inrush currents can cause on-board devices to fail and affect system reliability. Conventional protection methods, such as long and short pin connectors, hot-swappable interface chips and series resistors, plus TVS, etc., have the problems of high cost and large board area.

Chinese invention patent, publication number: 103166166B, publication date: June 1, 2016, the invention discloses that the invention involves a hot-swap controller. The invention aims at the problems of hot-swap controllers in the prior art, defects in soft-start function and unstable operation, and provides a protection circuit for hot-swap controllers to avoid misoperation of hot-swap controllers. The technical solution of the invention is that the heat The plug-in controller protection circuit includes a voltage detection circuit, a delay circuit and a switch circuit, the input end of the voltage detection circuit is connected to the input voltage and the reference voltage, and the output end of the voltage detection circuit is connected to the control end of the switch circuit through the delay circuit , the switch circuit is connected between the trigger terminal of the hot-swap controller and the ground. In the technical solution of the invention, by reasonably setting the detection voltage and the reference voltage, the switch can be turned on at the undervoltage point, and the voltage at the trigger terminal of the hot-swap controller can be pulled down, thereby closing the output voltage of the hot-swap controller, making it Avoid possible malfunctions caused by input voltage fluctuations. Its shortcoming is: this patent is aimed at the hot-swap control circuit of high-voltage power supply (+9V to+80V), and this circuit structure is complicated, takes up a large space, and price is high, is not suitable for mobile phone, computer, backplane power supply It is popularized and used in the field of industrial electronic equipment for +5V or +3.3V.

Utility model content

1. The technical problems to be solved by the utility model

Aiming at the problems of high cost and large occupied space of the P hot-swap circuit in the prior art, the utility model provides a hot-swap protection circuit. It can meet the requirements of extremely low cost and extremely small board area, and realize highly reliable hot-swap protection.

2. Technical solution

In order to solve the above problems, the technical solution provided by the utility model is:

A hot-swap protection circuit, including a data line protection circuit and a power supply protection circuit, wherein the data line protection circuit includes a pull-up resistor, a card slot and an EMI filter, and one end of the pull-up resistor is connected to the power supply of the EMI filter , the other end of the pull-up resistor is connected to the input end of the EMI filter and the data line terminal, and the output end of the EMI filter is connected to the card slot. The power supply protection circuit includes a high-side power switch and a TVS diode, and the high-side power switch input The terminal is connected to the power supply terminal, and the output terminal is connected to the card slot after being connected in parallel with the TVS diode.

Preferably, the EMI filter is a π-type filter circuit, and a TVS diode is connected in parallel at both ends of the π-type filter circuit.

Preferably, the EMI filter is TI's 4-channel TPD4F003 or 8-channel TPD8F003.

Preferably, the power supply of the EMI filter is a 3.3V DC voltage source.

Preferably, the model of the high-side power switch is AIC1526-0CS, and the TVS diode is SMBJ5.0CA.

Preferably, the terminal IN of the high-side power switch AIC1526-0CS is connected to a 3.3V DC voltage source, one end of the resistor R433, one end of the resistor R434, one end of the capacitor C3, and one end of the capacitor C220, and the other end of the capacitor C3 is connected to the capacitor C220. The other end is grounded, the terminal ENA of the high-side power switch AIC1526-0CS is connected to the data line end and the other end of the resistor R433, the other end of the resistor R434 is connected to the terminal ENB of the high-side power switch AIC1526-0CS, and the capacitor C222 and the capacitor C221 are connected in parallel , the terminals OUTA and OUTB of the high-side power switch AIC1526-0CS are respectively connected to both ends of the capacitor C222, the terminal OUTB of the high-side power switch AIC1526-0CS is grounded, and the terminal OUTA of the high-side power switch AIC1526-0CS is connected to the power supply VCC_SD.

Preferably, the power supply VCC_SD is connected to the port on the card slot, one end of the TVS diode SMBJ5.0CA and one end of the capacitor C223, and the other end of the TVS diode SMBJ5.0CA, the other end of the capacitor C223, and the port on the card slot are all grounded.

Preferably, the slot terminals GROUND1 and GROUND2 are both grounded.

Preferably, the card slot is connected with two 4-channel EMI filters TPD4F003 or with an 8-channel EMI filter TPD8F003.

Preferably, the resistance values of the pull-up resistor, the resistor R433 and the resistor 434 are all 10KΩ.

3. Beneficial effect

Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

(1) A hot-swap protection circuit of the present invention, in the data line protection circuit, the data line of the chip is combined with a pull-up resistor and an EMI filter to prevent overvoltage, overcurrent and overheating, and protect The internal structure and performance of the chip, in the power protection circuit, the high-side power switch and TVS diode work together to protect the chip;

(2) A kind of hot plug protection circuit of the present utility model, EMI filter is TPD4F003 of 4 channels or TPD8F003 of 8 channels of TI, and the power supply of described EMI filter is 3.3V DC voltage. In practical applications, the EMI filter with ESD protection can be determined according to the data line port of the chip, and finally each data line terminal of the chip is connected to the EMI filter to realize the protection of the data line;

(3) A kind of hot-swap protection circuit of the present utility model, the interior per channel circuit of EMI filter TPD4F003 is as shown in Figure 2, is a π-type (C-R-C) filter circuit, each adds a TVS diode at both ends, and the cost is 1 About RMB 1,000, low cost, occupying a board area of 1.7mm×1.35mm, slightly smaller than 0805-packaged chip resistors, occupying a small space, and can be popularized and used on mobile phones, computers, PADs and other equipment;

(4) A hot-swap protection circuit of the present invention, the high-side power switch AIC1526-0CS features: dual channels; 500mA continuous load current; current limiting/short circuit protection; thermal shutdown protection; undervoltage lockout; Function and fault indication, AIC1526-0CS is packaged in SO-8, the cost is about 1.5 yuan, and the cost is low. The TVS diode adopts SMBJ5.0CA, which is used for overvoltage protection. The cost is about 0.2 yuan, and the board area is up to 5.6mm×3.95mm. Reliable hot-plug protection;

(5) A kind of hot plug protection circuit of the present utility model, utilizes existing integrated circuit, and cost is low, and circuit structure is simple, and occupation space is little, and can be popularized and used on equipment such as CPU, chip, mobile phone;

(6) A hot-swap protection circuit of the present invention, the hot-swap protection circuit composed of the high-side power switch AIC1526-0CS and the EMI filter TPD4F003 basically has a hot-swap control circuit with under-voltage lockout and soft Start function, no need to add complicated control circuit.

Description of drawings

Fig. 1 is the data line protection circuit of the present utility model;

Fig. 2 is the π type filter circuit of the present utility model;

Fig. 3 is the power supply protection circuit of the present invention.

detailed description

In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the accompanying drawings and embodiments.

Example 1

In conjunction with Fig. 1-3, a kind of hot plug protection circuit comprises data line protection circuit and power supply protection circuit, wherein, as shown in Fig. 1, data line protection circuit comprises pull-up resistor, card slot and EMI filter, described One end of the pull-up resistor is connected to the power supply of the EMI filter, the other end of the pull-up resistor is connected to the input end of the EMI filter and the data line terminal, and the output end of the EMI filter is connected to the card slot, as shown in Figure 3. The power supply protection circuit includes a high-side power switch and a TVS diode, the input end of the high-side power switch is connected to the power terminal, and the output end is connected in parallel with the TVS diode to the card slot.

A hot plug protection circuit of this embodiment, in the data line protection circuit, the data line of the chip acts in combination with a pull-up resistor and an EMI filter to prevent overvoltage, overcurrent and overheating, and protect the internal structure of the chip Performance, in the power protection circuit, the high-side power switch and TVS diode work together to protect the chip.

Example 2

A hot-swap protection circuit of this embodiment is similar to Embodiment 1, wherein the EMI filter is a π-type filter circuit, and a TVS diode is connected in parallel at both ends of the π-type filter circuit, as shown in FIG. 2 As shown, the terminal Ch_In is the input terminal of the EMI filter, the terminal Ch_Out is the output terminal of the EMI filter, the resistance value in the EMI filter is 100Ω, and the size of the two capacitors is 8.5pF.

Example 3

A kind of hot plug protection circuit of the present embodiment is similar to embodiment 1, wherein, described EMI filter is the TPD4F003 of TI's 4 passages or the TPD8F003 of 8 passages, and the power supply of described EMI filter is 3.3 V DC voltage. In practical applications, the EMI filter with ESD protection can be determined according to the data line port of the chip, and finally each data line terminal of the chip is connected to the EMI filter to realize the protection of the data line.

The internal per-channel circuit of the EMI filter TPD4F003 is shown in Figure 2. It is a π-type (C-R-C) filter circuit with a TVS diode at each end. The cost is about 1 yuan, and the cost is low. The board area is 1.7mm×1.35mm. Chip resistors slightly smaller than the 0805 package, occupying a small space, can be popularized and used on mobile phones, computers, PADs and other equipment.

Example 4

A hot-swap protection circuit of this embodiment is similar to Embodiment 1, wherein the model of the high-side power switch is AIC1526-0CS, and the TVS diode is SMBJ5.0CA. The antistatic performance of the high-side power switch AIC1526-0CS is: air discharge ±20KV, contact discharge ±12KV, -3dB bandwidth 200MHz.

High-side power switch AIC1526-0CS features: dual-channel; 500mA continuous load current; current limit/short circuit protection; thermal shutdown protection; It is about 1.5 yuan, and the cost is low. The TVS diode adopts SMBJ5.0CA, which is used for overvoltage protection. The cost is about 0.2 yuan, and the board area is up to 5.6mm×3.95mm. Reliable hot-swap protection.

As shown in Figure 3, the terminal IN of the high-side power switch AIC1526-0CS is connected to the 3.3V DC voltage source, one end of the resistor R433, one end of the resistor R434, one end of the capacitor C3, and one end of the capacitor C220, and the other end of the capacitor C3 is connected to The other end of the capacitor C220 is grounded, the terminal ENA of the high-side power switch AIC1526-0CS is connected to the data line end and the other end of the resistor R433, the other end of the resistor R434 is connected to the terminal ENB of the high-side power switch AIC1526-0CS, and the capacitors C222 and The capacitor C221 is connected in parallel, the terminal OUTA and the terminal OUTB of the high-side power switch AIC1526-0CS are respectively connected to both ends of the capacitor C222, the terminal OUTB of the high-side power switch AIC1526-0CS is grounded, and the terminal OUTA of the high-side power switch AIC1526-0CS is connected to the power supply VCC_SD.

The power supply VCC_SD is connected to the port on the card slot, one end of the TVS diode SMBJ5.0CA and one end of the capacitor C223, and the other end of the TVS diode SMBJ5.0CA, the other end of the capacitor C223 and the port on the card slot are all grounded.

In FIG. 3 , the resistance values of the resistor R433 and the resistor R434 are both 10KΩ, the capacitor C3 and the capacitor C222 are both 0.1uF, and the capacitor C221 is 10uF.

This embodiment utilizes the existing integrated circuit, which has low cost, simple circuit structure and small footprint, and can be popularized and used in industrial electronic equipment, computers, mobile phones and other equipment.

Example 5

A hot-plug protection circuit of this embodiment is similar to Embodiment 1, wherein the card slot terminals GROUND1 and GROUND2 are both grounded, and the card slot is connected to two 4-channel EMI filters TPD4F003 or connected to an 8-channel EMI filter TPD4F003 The EMI filter TPD8F003 realizes the effect of protecting all data line terminals of the chip, and the resistance value of the pull-up resistor, resistor R433 and resistor R434 is 10KΩ.

The above schematically describes the utility model and its implementation, which is not restrictive, and what is shown in the accompanying drawings is only one implementation of the utility model, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, and without departing from the purpose of the invention of the utility model, without creatively designing a structural mode and an embodiment similar to the technical solution, it shall belong to the utility model. protected range.

Claims (10)

1. a kind of hot plug protection circuit, it is characterised in that including data wire protection circuit and power protecting circuit, wherein, number Include pull-up resistor, neck and electromagnetic interface filter according to line protection circuit, described pull-up resistor one end connects the confession of electromagnetic interface filter Power supply, the pull-up resistor other end and electromagnetic interface filter input and data line terminal connection, the output end of electromagnetic interface filter with Neck is connected, and described power protecting circuit includes flash power switch and TVS diode, flash power switch input and electricity Source terminal is connected, and is connected after output end is in parallel with TVS diode with neck.

2. a kind of hot plug protection circuit according to claim 1, it is characterised in that described electromagnetic interface filter is filtered for π types Wave circuit, in each TVS diode in parallel in the two ends of π type filter circuits.

3. a kind of hot plug protection circuit according to claim 1 or 2, it is characterised in that described electromagnetic interface filter is 4 The TPD4F003 of passage or 8 passages TPD8F003.

4. a kind of hot plug protection circuit according to claim 3, it is characterised in that the power supply of described electromagnetic interface filter Power supply is 3.3V direct voltage sources.

5. a kind of hot plug protection circuit according to claim 1, it is characterised in that the type of described flash power switch Number it is AIC1526-0CS, described TVS diode is SMBJ5.0CA.

6. a kind of hot plug protection circuit according to claim 5, it is characterised in that flash power switch AIC1526- 0CS terminal IN and 3.3V direct voltage sources, resistance R433 one end, resistance R434 one end, electric capacity C3 one end and electric capacity C220 one end connection, the electric capacity C3 other end and electric capacity C220 other end ground connection, flash power switch AIC1526-0CS's Terminal ENA is connected with the other end of data line end, resistance R433, resistance the R434 other end and flash power switch AIC1526- 0CS terminal ENB connections, electric capacity C222 and electric capacity C221 are in parallel, flash power switch AIC1526-0CS terminal OUTA and end Sub- OUTB is connected to electric capacity C222 two ends, flash power switch AIC1526-0CS terminal OUTB ground connection, flash power supply Switch AIC1526-0CS terminal OUTA meets power supply VCC_SD.

7. a kind of hot plug protection circuit according to claim 6, it is characterised in that power supply VCC_SD and the end on neck One end connection of mouth, TVS diode SMBJ5.0CA one end and electric capacity C223, TVS diode the SMBJ5.0CA other end, electricity The port held on the C223 other end and neck is grounded.

8. a kind of hot plug protection circuit according to claim 1, it is characterised in that neck terminal GROUND1 and GROUND2 is grounded.

9. a kind of hot plug protection circuit according to claim 3, it is characterised in that described neck connects 24 passages Electromagnetic interface filter TPD4F003 or connect 8 passages electromagnetic interface filter TPD8F003.

10. a kind of hot plug protection circuit according to claim 6, it is characterised in that described pull-up resistor, resistance The resistance value of R433 and resistance 434 is 10K Ω.