Hot plug power-on control circuit

Abstract

The utility model discloses a hot plug power-on control circuit, which comprises a connecting interface, an in-place detection module and a power-on control module which are sequentially connected in series, the connecting interface is connected with pluggable equipment, and when the in-place detection module detects that the pluggable equipment on the connecting interface is in place, the power-on control module is connected with the in-place detection module. The power-on control module delays to supply power to the pluggable device to start the pluggable device, otherwise, the power-on control module does not supply power to the connecting interface, the pluggable device is delays to supply power to the pluggable device when the pluggable device is in place by detecting whether the pluggable device is in place or not, and the power-on control module detects whether the pluggable device is in place or not and then delays to supply power to the pluggable device when the pluggable device is in place. And a hot plug chip is not needed, so that the product cost is reduced.

Description

Technical Field

[0001] The utility model relates to a hot-plug power supply technology for electronic equipment, in particular to a hot-plug power-on control circuit. Background Art

[0002] The hot-swap function allows users to remove and replace damaged hard disks, power supplies, or boards without shutting down the system or cutting off the power supply, thereby improving the system's ability to recover from disasters in a timely manner, as well as its scalability and flexibility. However, hot-swap boards are prone to overvoltage and overcurrent glitches, which can damage circuits. Therefore, hot-swap interfaces generally require hot-swap protection, overvoltage protection, overcurrent protection, and power limits.

[0003] For example, in the Chinese utility model patent with application number 201721267367.5, entitled A hot-swap power supply system, the hot-swap power management chip provides high voltage according to the detected signal, limits high surge current, and the voltage stabilization circuit stabilizes the output voltage, thereby preventing surge current from damaging the device during the hot-swap process. However, this method requires the use of a dedicated hot-swap chip, which is relatively expensive. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present utility model is to provide a hot-swap power-on control circuit, which can delay powering a pluggable device after detecting that the pluggable device is in place.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A hot-swap power-on control circuit comprises a connection interface, a presence detection module and a power-on control module connected in series in sequence, wherein the connection interface is connected to a pluggable device, and when the presence detection module detects that the pluggable device is in place on the connection interface, the power-on control module delays supplying power to the pluggable device to enable the pluggable device to start up, otherwise the connection interface is not powered.

[0007] Optionally, the in-place detection module includes a first overvoltage protection unit, a in-place detection unit and a first filtering unit. The ground pin of the connection interface is connected to the first overvoltage protection unit and is also connected to the power-on control module through the in-place detection unit and the first filtering unit in sequence.

[0008] Optionally, the in-place detection unit includes a first resistor, a first inductor and a first diode, one end of the first resistor is connected to the VDD power supply end, the other end of the first resistor is connected to the positive electrode of the first diode through the first inductor, and the negative electrode of the first diode is connected to the ground pin of the connection interface and one end of the first overvoltage protection unit.

[0009] Optionally, the first overvoltage protection unit includes a second diode, one end of the second diode is connected to the cathode of the first diode and a ground pin of the connection interface, and the other end of the second diode is grounded.

[0010] Optionally, the first filtering unit includes a second resistor and a first capacitor, one end of the second resistor is respectively connected to one end of the first resistor and the first inductor and is also grounded through the first capacitor, and the other end of the second resistor is connected to the power-on control module.

[0011] Optionally, the in-place detection module further includes a clamping diode, a first end of the clamping diode is grounded, a second end of the clamping diode is connected to the other end of the second resistor and the power-on control module, and a third end of the clamping diode is connected to the VDD power supply terminal.

[0012] Optionally, the power-on control module includes a delay switch unit, a second filtering unit and a second overvoltage protection unit. When the in-place detection module detects that the pluggable device is in place, the delay switch unit is turned on so that the supply voltage is filtered by the second filtering unit and stabilized by the second overvoltage protection unit, and then transmitted to the power supply pin of the connection interface to delay powering the pluggable device.

[0013] Optionally, the delay switch unit includes a first MOS tube, a second MOS tube, a third MOS tube, a second capacitor, a third diode, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, the gate of the first MOS tube is connected to one end of the first filtering unit through the third resistor and is also grounded through the fourth resistor, the drain of the first MOS tube is connected to the negative electrode of the third diode and the gate of the second MOS tube and is also grounded through the second capacitor, the positive electrode of the third diode is connected to the voltage input end, the source of the first MOS tube and the source of the second MOS tube are grounded, the drain of the second MOS tube is connected to one end of the sixth resistor and the gate of the third MOS tube through the fifth resistor, the source of the third MOS tube is connected to the other end of the sixth resistor and the power input end, the drain of the third MOS tube is connected to the second overvoltage protection unit through the second filtering unit, and the source of the third MOS tube is connected to the power input end.

[0014] Optionally, the second filtering unit includes the second inductor and the third inductor, one end of the second inductor is connected to the drain of the third MOS tube, the other end of the second inductor is connected to the power supply pin of the connection interface, and the third inductor is connected in parallel with the second inductor.

[0015] Optionally, the pluggable device is an evaporator.

[0016] Compared with the prior art, the hot-swap power-on control circuit provided by the utility model includes a connection interface connected to a pluggable device, a presence detection module and a power-on control module. When the presence detection module detects that the pluggable device is in place on the connection interface, the power-on control module delays powering the pluggable device to turn on the pluggable device. Otherwise, the connection interface is not powered. By detecting whether the pluggable device is in place, the pluggable device is powered on with a delay when the pluggable device is in place. The method of first detecting whether the device is in place and then delaying the power supply is adopted. There is no need to use a hot-swap chip, thereby reducing product costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural block diagram of the hot-swap power-on control circuit provided by the utility model.

[0018] Figure 2 The utility model provides a circuit schematic diagram of a hot-swap power-on control circuit for a pre-situation detection module.

[0019] Figure 3 The utility model provides a circuit schematic diagram of a power-on control module in a hot-swap power-on control circuit.

[0020] Description of Reference Numerals

[0021] Connection interface J1, presence detection module 10, first overvoltage protection unit 11, presence detection unit 12, first filtering unit 13, power-on control module 20, delay switch unit 21, second filtering unit 22, second overvoltage protection unit 23, first resistor R1, first inductor L1, first diode D1, second diode D2, second resistor R2, first capacitor C1, clamping diode DV, first MOS tube Q1, second MOS tube Q2, third MOS tube Q3, second capacitor C2, third diode D3, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, second inductor L2, third inductor L3, fourth diode D4, third capacitor C3 DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] The hot-swap power-on control circuit provided by the utility model is arranged on the bottom plate, and is used for detecting whether the pluggable device is connected in place, and when it is detected that it is in place, the pluggable device is powered on with a delay, that is, the bottom plate automatically powers on the evaporator board after the pluggable device is hot-swapped.

[0024] See also Figure 1The hot-swap power-on control circuit includes: a connection interface J1, a presence detection module 10 and a power-on control module 20 connected in series in sequence, the connection interface J1 is connected to the pluggable device (such as plugging), the ground pin of the connection interface J1 is connected to the power-on control module 20 through the presence detection module 10, and the output end of the power-on control module 20 is connected to the power supply pin of the connection interface J1.

[0025] When the presence detection module 10 detects that a pluggable device is present on the connection interface J1, the power-on control module 20 delays supplying power to the pluggable device to start the pluggable device, otherwise the connection interface J1 is not powered. By detecting whether the pluggable device is present, the pluggable device is powered on with a delay when the pluggable device is present. By first detecting whether the device is present and then delaying the power supply, there is no need to use a hot-swap chip, thereby reducing product costs.

[0026] In this embodiment, the in-place detection module 10 includes a first overvoltage protection unit 11, an in-place detection unit 12 and a first filtering unit 13. The grounding pin of the connection interface J1 is connected to the first overvoltage protection unit 11, and is also connected to the power-on control module 20 through the in-place detection unit 12 and the first filtering unit 13. The first overvoltage protection unit 11 and the first filtering unit 13 are used to provide overvoltage and overcurrent protection to prevent damage to the subsequent circuit when the pluggable device is hot-plugged in response to overvoltage and overcurrent spike signals. The in-place detection unit 12 is used to detect whether the grounding pin of the connection interface J1 is connected to the grounding pin of the pluggable device. When connected, it indicates that the pluggable device is installed in place.

[0027] Optionally, the pluggable device is a hot-pluggable electrical device such as an evaporator, a USB flash drive, a disk, a network cable, etc. Figure 1 and Figure 2 The presence detection unit 12 includes a first resistor R1, a first inductor L1 and a first diode D1, one end of the first resistor R1 is connected to a VDD power supply end (such as a VDD3V3 power supply end), the other end of the first resistor R1 is connected to a positive electrode of the first diode D1 through the first inductor L1, and a negative electrode of the first diode D1 is connected to a ground pin of the connection interface J1 and one end of the first overvoltage protection unit 11.

[0028] The first diode D1 is used to prevent reverse current, the first inductor L1 is a magnetic bead inductor, which mainly plays a filtering role, and the first resistor R1 is a pull-up resistor.

[0029] The first overvoltage protection unit 11 includes a second diode D2, one end of which is connected to the cathode of the first diode D1 and the ground pin of the connection interface J1, and the other end of the second diode D2 is grounded. The second diode D2 can be a WS05DLC-B electrostatic protection diode, which can perform overvoltage protection at the moment of hot plugging of the pluggable device to prevent overvoltage damage to the subsequent circuit.

[0030] Please continue reading Figure 1 and Figure 2 The first filtering unit 13 includes a second resistor R2 and a first capacitor C1, one end of the second resistor R2 is respectively connected to one end of the first resistor R1 and one end of the first inductor L1, and is also grounded through the first capacitor C1, and the other end of the second resistor R2 is connected to the power-on control module 20. The second resistor R2 mainly plays a current limiting role, and the first capacitor C1 is a filter capacitor for filtering voltage and current peaks.

[0031] Furthermore, the in-place detection module 10 further includes a clamping diode DV, the first end of which is grounded, the second end of which is connected to the other end of the second resistor R2 and the power-on control module 20, and the third end of which is connected to the VDD power supply terminal. The clamping diode DV is used to clamp the level of the ground pin of the connection interface J1, which is a high level in the default state. Figure 2 EVPON1 in the device is left floating by default.

[0032] Taking the pluggable device as an evaporator as an example, when the evaporator is not plugged in, EVPON1 is suspended, and PU_FB_EVPON1 is pulled up to the IO port of the main control chip of the 3.3V device (such as anesthesia machine) by default. When the evaporator board is plugged into the connection interface J1, the ground pin of the connection interface J1 is connected to the ground pin of the evaporator, and the IO port level of the main control chip is connected to a low level, which means that the evaporator is plugged into the base plate.

[0033] Please also read Figures 1 to 3 The power-on control module 20 includes a delay switch unit 21, a second filter unit 22 and a second overvoltage protection unit 23, and the delay switch unit 21, the second filter unit 22 and the second overvoltage protection unit 23 are connected in sequence.

[0034] When the presence detection module 10 detects that the pluggable device is in place, the delay switch unit 21 is turned on so that the power supply voltage is filtered by the second filter unit 22 and stabilized by the second overvoltage protection unit 23, and then input to the power supply pin of the connection interface J1 to delay powering the pluggable device.

[0035] The delay switch unit 21 includes a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, a second capacitor C2, a third diode D3, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6. The first MOS transistor Q1 and the second MOS transistor Q2 are N-channel MOS transistors, which are turned on when their gates are at a high level, and the third MOS transistor Q3 is a P-channel MOS transistor, which is turned on when its gate is at a low level. The second capacitor C2 is a delay capacitor, and the delay time is set by the capacitance value. The fifth resistor R5 and the sixth resistor R6 are voltage-dividing resistors to prevent the VGS voltage of the third MOS transistor Q3 from being too high.

[0036] The gate of the first MOS transistor Q1 is connected to one end of the first filtering unit 13 through the third resistor R3 and is also grounded through the fourth resistor R4. The drain of the first MOS transistor Q1 is connected to the cathode of the third diode D3 and the gate of the second MOS transistor Q2 and is also grounded through the second capacitor C2. The anode of the third diode D3 is connected to the voltage input terminal. The source of the first MOS transistor Q1 and the source of the second MOS transistor Q2 are grounded. The drain of the second MOS transistor Q2 is connected to one end of the sixth resistor R6 and the gate of the third MOS transistor Q3 through the fifth resistor R5. The source of the third MOS transistor Q3 is connected to the other end of the sixth resistor R6 and the power input terminal. The drain of the third MOS transistor Q3 is connected to the second overvoltage protection unit 23 through the second filtering unit 22, and the source of the third MOS transistor Q3 is connected to the power input terminal.

[0037] The second filtering unit 22 includes a second inductor L2 and a third inductor L3, one end of the second inductor L2 is connected to the drain of the third MOS tube Q3, the other end of the second inductor L2 is connected to the power supply pin of the connection interface J1, and the third inductor L3 is connected in parallel with the second inductor L2. The second inductor L2 and the third inductor L3 are magnetic bead inductors, which play a filtering role and are used to filter out power peaks before supplying power to the evaporator.

[0038] The second overvoltage protection unit 23 includes a fourth diode D4, the cathode of the fourth diode D4 is connected to the other end of the second inductor L2 and the power supply pin of the connection interface J1, and the anode of the fourth diode D4 is grounded. The fourth diode D4 can be a TVS diode, such as a 1SMB6.5AT3G diode, which mainly plays an overvoltage protection function. When the device control chip recognizes that the evaporator is in place, the second MOS tube Q2 can be turned on with a delay, and then the third MOS tube Q3 can be turned on, so that the input voltage VPWR can be output to the evaporator through the second filter unit 22 and the second overvoltage protection unit 23. Power.

[0039] Furthermore, the delay switch unit 21 also includes a third capacitor C3, one end of the third capacitor C3 is connected to the source of the third MOS tube Q3, and the other end is connected to one end of the sixth resistor R6. The third capacitor C3 is a soft start capacitor of the third MOS tube Q3 and is used to protect the third MOS tube Q3.

[0040] In order to better understand the technical solution of the utility model, the following evaporator hot plug is used as an application example and combined with Figures 1 to 3 The working principle of the hot-swap power-on control circuit of the utility model is described in detail:

[0041] When the evaporator board is not plugged into the baseboard, EVPON1 is suspended by default. At this time, CPU_FB_EVPON1 is pulled up to 3.3V by default, and the IO port of the device main control chip detects a high level.

[0042] When the evaporator board is plugged into the base plate, the ground of the evaporator board is connected to the ground of the connection interface J1, so that EVPON1 is also connected to the ground of the evaporator board. Then the first diode D1 is turned on, and the power supply end VDD3V3 passes through the first resistor R1, the first inductor L1, and the first diode D1 to the ground. At this time, the voltage of CPU_FB_EVPON1 is about 0.7V, and the IO port of the main control chip detects a low level.

[0043] When the evaporator is unplugged and the evaporator board is not in place, CPU_FB_EVPON1 is high at 3.3V, the first MOS tube Q1 is turned on, making the gate voltage of the second MOS tube Q2 0V. At this time, the second MOS tube Q2 is cut off, and the gate voltage of the third MOS tube Q3 is equal to the source voltage VPWR. The third MOS is turned off, the output has no voltage, and the evaporator is powered off and shut down.

[0044] When the evaporator is plugged in, CPU_FB_EVPON1 is at a low level of 0.7V, the first MOS tube Q1 is cut off, and the power supply voltage VPWR charges the second capacitor C2 through the third diode D3 and the current limiting resistor R7. When the gate voltage of the second MOS tube Q2 is greater than the turn-on voltage, the second MOS tube Q2 is turned on, so that the first MOS tube Q1 is turned on, and the power supply voltage VPWR outputs VPWRA through the second inductor L2, so that the evaporator is powered on, thereby realizing that after the evaporator board is plugged into the bottom plate and grounded, the PMOS is delayed to power the evaporator, and the grounding is first connected and then the positive pole of the power supply is connected. The output voltage and current are stable, and there is no need to use a hot-swap chip.

[0045] To sum up, the utility model detects whether the pluggable device is in place and delays powering the pluggable device when the pluggable device is in place. It adopts the method of first detecting whether the device is in place and then delaying power supply. It only uses a few conventional electronic components and does not need to use hot-swappable chips, thereby reducing product costs.

[0046] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and utility model concept of the utility model, and all these changes or substitutions should fall within the protection scope of the claims attached to the utility model.

Claims

1. A hot-swap power-on control circuit, characterized in that: The invention comprises a connection interface, a presence detection module and a power-on control module which are connected in series in sequence. The connection interface is connected to a pluggable device. When the presence detection module detects that the pluggable device is in place on the connection interface, the power-on control module delays supplying power to the pluggable device to start the pluggable device. Otherwise, the connection interface is not powered.

2. The hot-swap power-on control circuit according to claim 1, characterized in that: The in-place detection module includes a first overvoltage protection unit, an in-place detection unit and a first filtering unit. The ground pin of the connection interface is connected to the first overvoltage protection unit and is also connected to the power-on control module through the in-place detection unit and the first filtering unit in sequence.

3. The hot-swap power-on control circuit according to claim 2, characterized in that: The presence detection unit includes a first resistor, a first inductor and a first diode, one end of the first resistor is connected to the VDD power supply end, the other end of the first resistor is connected to the positive electrode of the first diode through the first inductor, and the negative electrode of the first diode is connected to the ground pin of the connection interface and one end of the first overvoltage protection unit.

4. The hot-swap power-on control circuit according to claim 3, characterized in that: The first overvoltage protection unit includes a second diode, one end of the second diode is connected to the cathode of the first diode and the ground pin of the connection interface, and the other end of the second diode is grounded.

5. The hot-swap power-on control circuit according to claim 4, characterized in that: The first filtering unit includes a second resistor and a first capacitor, one end of the second resistor is respectively connected to one end of the first resistor and the first inductor and is also grounded through the first capacitor, and the other end of the second resistor is connected to the power-on control module.

6. The hot-swap power-on control circuit according to claim 5, characterized in that: The in-place detection module also includes a clamping diode, a first end of the clamping diode is grounded, a second end of the clamping diode is connected to the other end of the second resistor and the power-on control module, and a third end of the clamping diode is connected to the VDD power supply terminal.

7. The hot-swap power-on control circuit according to claim 2, characterized in that: The power-on control module includes a delay switch unit, a second filtering unit and a second overvoltage protection unit. When the in-place detection module detects that the pluggable device is in place, the delay switch unit is turned on to allow the supply voltage to be filtered by the second filtering unit and stabilized by the second overvoltage protection unit, and then transmitted to the power supply pin of the connection interface to delay powering the pluggable device.

8. The hot-swap power-on control circuit according to claim 7, characterized in that: The delay switch unit includes a first MOS tube, a second MOS tube, a third MOS tube, a second capacitor, a third diode, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor. The gate of the first MOS tube is connected to one end of the first filtering unit through the third resistor and is also grounded through the fourth resistor. The drain of the first MOS tube is connected to the negative electrode of the third diode and the gate of the second MOS tube and is also grounded through the second capacitor. The positive electrode of the third diode is connected to the voltage input end. The source of the first MOS tube and the source of the second MOS tube are grounded. The drain of the second MOS tube is connected to one end of the sixth resistor and the gate of the third MOS tube through the fifth resistor. The source of the third MOS tube is connected to the other end of the sixth resistor and the power input end. The drain of the third MOS tube is connected to the second overvoltage protection unit through the second filtering unit, and the source of the third MOS tube is connected to the power input end.

9. The hot-swap power-on control circuit according to claim 8, characterized in that: The second filtering unit includes a second inductor and a third inductor, one end of the second inductor is connected to the drain of the third MOS tube, the other end of the second inductor is connected to the power supply pin of the connection interface, and the third inductor is connected in parallel with the second inductor.

10. The hot-swap power-on control circuit according to any one of claims 1 to 9, characterized in that: The pluggable device is an evaporator.

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