TW201820787A - Hot swapping circuit performs multi-layered protection by disposing the detection module, the delay module, and the hysteresis module - Google Patents

Abstract

A hot swapping circuit comprises a power source end and a grounding end, a detection module, a delay module, a hysteresis module and a switch module. The detection module is used for receiving a connection signal relative to whether or not a hot swapping device is connected and filtering the connection signal to output a connection state signal. The delay module is electrically connected to the detection module to receive the connection state signal and, based upon the connection state signal, delays and outputs a connection steady signal in order to eliminate signal surge. The hysteresis module is electrically connected to the delay module to receive the connection steady signal and outputs a switch signal after performing hysteresis process. The switch module is electrically connected to the hysteresis module to receive the switch signal and outputs and does not output a hot swapping power based upon the switch signal. Accordingly, the foregoing can effectively prevent elements from being damaged due to surge, noise and jitter signals, capable of enhancing service life and improving stability of operation.

Description

Hot-swap circuit

The invention relates to an electronic circuit, in particular to a hot-swap circuit.

Hot swapping (Hot swapping or Hot plugging) technology is very convenient because users can plug in or unplug hardware without turning off the power. In industrial applications, it is widely used because it can avoid the need to restart the controller when the teaching device is removed, so it can greatly reduce the time and cost of restarting the controller. However, it is widely used in industry. The applied voltage is high, so how to avoid the impact of surge and maintain the stability of the circuit has become a topic of concern.

Therefore, an object of the present invention is to provide a hot-swap circuit which can avoid the influence of surge and maintain the stability of the circuit.

Therefore, the hot-swap circuit of the present invention is suitable for providing a hot-swap power supply to a hot-swap device, and includes a power terminal and a ground terminal, a detection module, a delay module, and a hysteresis module. And a switch module.

The detection module is used for receiving a connection signal related to whether the hot-plugging device is connected, and filtering the connection signal to output a connection status signal.

The delay module is electrically connected to the detection module, receives the connection status signal, and delays outputting a connection stability signal according to the connection status signal to eliminate a signal surge.

The hysteresis module is electrically connected to the delay module, receives the connection stabilization signal, and outputs a switching signal after performing the hysteresis processing.

The switch module is electrically connected to the hysteresis module, receives the switch signal, and outputs and does not output the hot-swap power supply according to the switch signal.

The effect of the present invention is that by setting the detection module, the delay module, and the hysteresis module for multi-layer protection, it can effectively prevent component damage caused by surges, noise, and jitter signals, so that the service life can be improved. And can reduce the misjudgment of interference and improve the stability of operation.

Referring to FIG. 1, an embodiment of the hot-swap circuit of the present invention is applicable to provide a hot-swap power supply to a hot-swap device (not shown), and includes a power terminal VCC, a ground terminal GND, and a detection Module 2, a delay module 3, a hysteresis module 4, and a switch module 5.

The detection module 2 is used for receiving a connection signal related to whether the hot-plugging device is connected, and filtering the connection signal to output a connection status signal.

The detection module 2 includes a receiving end 21 for receiving the connection signal, an output end 22 for outputting the connection state signal, and a first detection for electrically connecting the receiving end 21 and the output end 22 respectively at both ends. A resistor 23, a second detection resistor 24 electrically connected to the power terminal VCC and the receiving terminal 21 at one end, and a detection capacitor 25 electrically connected to the output terminal 22 and the ground GND at both ends, respectively.

The delay module 3 is electrically connected to the detection module 2, receives the connection status signal, and delays and outputs a connection stability signal according to the connection status signal to eliminate a signal surge.

The delay module 3 includes a first delay transistor 31, a second delay transistor 32, a delay capacitor 33, a delay diode 34, a first delay resistor 35, and a second delay resistor 36.

The first delay transistor 31 has a first terminal, a second terminal electrically connected to the power terminal VCC, and a control terminal for receiving the connection status signal. In this embodiment, the first delay transistor 31 is a P-type Metal-Oxide-Semiconductor Field-Effect Transistor (abbreviated as MOSFET), and its first end is a source. The second terminal is the drain and the control terminal is the gate, but it can be changed according to the actual circuit design and is not limited to this.

The second delay transistor 32 has a first terminal electrically connected to the second terminal of the first delay transistor 31, a second terminal electrically connected to the ground terminal GND, and a control terminal for receiving the connection status signal. . In this embodiment, the second delay transistor 32 is an N-type metal-oxide half-field-effect transistor, and the first terminal is a drain, the second terminal is a source, and the control terminal is a gate. Gate, but can be changed according to the actual circuit design, and is not limited to this.

The delay capacitor 33 has a first terminal electrically connected to the second terminal of the first delay transistor 31 and used to output the connection stable signal, and a second terminal electrically connected to the ground terminal GND.

The delay diode 34 is electrically connected between the second terminal of the first delay transistor 31 and the first terminal of the delay capacitor 33, and has an anode terminal electrically connected to the delay capacitor 33 and an electrical terminal The cathode terminal of a delay transistor 31.

The two ends of the first delay resistor 35 are electrically connected to the anode terminal and the cathode terminal of the delay diode 34 respectively.

The second delay resistor 36 is electrically connected between the second terminal of the second delay transistor 32 and the ground terminal GND.

The hysteresis module 4 is electrically connected to the delay module 3, receives the connection stabilization signal, and outputs a switching signal after performing the hysteresis processing.

The hysteresis module 4 includes an operational amplifier 41, a first hysteresis resistor 42, a second hysteresis resistor 43, a third hysteresis resistor 44, and a fourth hysteresis resistor 45.

The operational amplifier 41 has a reverse input terminal for receiving the connection stabilization signal, a forward input terminal, and an amplified output terminal for outputting the switching signal.

The first hysteresis resistor 42 has a first terminal electrically connected to the power terminal VCC, and a second terminal.

The second hysteresis resistor 43 has a first terminal electrically connected to a second terminal of the first hysteresis resistor 42 and a second terminal electrically connected to a positive input terminal of the operational amplifier 41.

The third hysteresis resistor 44 has a first terminal electrically connected to the second terminal of the second hysteresis resistor 43 and a second terminal electrically connected to the amplified output terminal of the operational amplifier 41.

The fourth hysteresis resistor 45 has a first terminal electrically connected to the second terminal of the first hysteresis resistor 42 and a second terminal electrically connected to the ground terminal GND.

The switching module 5 is electrically connected to the hysteresis module 4, receives the switching signal, and outputs and does not output the hot-swap power according to the switching signal.

The switching module 5 includes a switching transistor 51, a first switching resistor 52, and a second switching resistor 53.

The switching transistor 51 has a first terminal electrically connected to the power terminal VCC, a second terminal for outputting the hot-swap power supply, and a control terminal for receiving the switching signal.

In this embodiment, the switching transistor 51 is a P-type metal-oxide half field effect transistor, and the first terminal is a source, the second terminal is a drain, and the control terminal is a gate ( Gate), but may vary depending on the actual circuit design, and is not limited to this.

The first switching resistor 52 has a first terminal electrically connected to the power terminal VCC, and a second terminal electrically connected to the control terminal of the switching transistor 51.

The two ends of the second switching resistor 53 are respectively electrically connected to the amplification output terminal of the operational amplifier 41 and the control terminal of the switching transistor 51. The control terminal of the switching transistor 51 receives the switching signal via the second switching resistor 53.

Referring to FIGS. 1 and 2 to 5, waveforms 91 to 94 are the connection status signal output from the output terminal 22 of the detection module 2 and the connection stabilization signal output from the first terminal of the delay capacitor 33, respectively. The voltage measurement waveforms of the switching signal output from the amplified output terminal of the operational amplifier 41 and the hot-swap power supply output from the second terminal of the switching transistor, and on the vertical axis, each division represents 10 volts (V).

In actual use, the circuit architecture of this embodiment is used as an illustration. When the hot-swap device is not plugged in, the voltage of the first terminal of the detection capacitor 25 will pass through the first detection resistor 23 and the second detection circuit. The resistance 24 is measured to be charged to the high-level voltage by the power terminal VCC, and the connection state signal of the high-level voltage is output at the output terminal 22.

The control terminal of the first delay transistor 31 and the control terminal of the second delay transistor 32 of the delay module 3 receive the connection status signal of a high level voltage, so that the first delay transistor 31 is not turned on. The second delay transistor 32 is turned on. In this way, the first terminal of the delay capacitor 33 is grounded through the delay diode 34, the second delay transistor 32, and the second delay resistor 36, so that the voltage drops. To the low level voltage and output the connection stabilization signal of the low level voltage.

The inverting input of the operational amplifier 41 of the hysteresis module 4 receives the connection stabilization signal of a low level voltage, and outputs the switching signal of a high level voltage at the amplified output terminal, so that the switching module 5 The switching transistor 51 is non-conductive and does not output the hot-swap power to the hot-swap device.

When the hot-swap device is inserted into the connection, the connection signal with a low level voltage is output to the receiving terminal 21, so as shown in FIG. 2, the voltage of the first terminal of the detection capacitor 25 will follow The voltage is reduced to a low level voltage, and the connection state signal of a low level voltage is output at the output terminal 22.

The control terminal of the first delay transistor 31 and the control terminal of the second delay transistor 32 of the delay module 3 receive the connection state signal of a low level voltage, so that the first delay transistor 31 is turned on, The second delay transistor 32 is not conductive, so that the first terminal of the delay capacitor 33 is electrically connected to the power terminal VCC via the first delay resistor 35 and the first delay transistor 31, as shown in FIG. 3, The voltage of the first terminal of the delay capacitor 33 is gradually increased to a high level voltage by the power terminal VCC, and is output as the connection stabilization signal.

The inverting input terminal of the operational amplifier 41 of the hysteresis module 4 receives the connection stabilization signal, and as shown in FIG. 4, after the connection stabilization signal is pulled up to a high threshold voltage, a low accuracy is output at the amplification output terminal. The switching signal of the potential voltage causes the switching transistor 51 of the switching module 5 to be turned on and the power terminal VCC to be connected to the second terminal of the switching transistor 51 to output the hot-swap power supply to the hot-swap device ( (As shown in Figure 5).

Referring to FIGS. 1 and 6 to 9, when the hot-swap device is unplugged and disconnected, the voltage at the first end of the detection capacitor 25 passes through the first detection resistor 23 and the second detection resistor again. 24 and the VCC is charged to a high level voltage by the power terminal, and the high level voltage is output at the output terminal 22, so that the first delay transistor 31 of the delay module 3 is not turned on and the second delay transistor 32 is turned on In this way, the voltage at the first end of the delay capacitor 33 is grounded via the delay diode 34, the second delay transistor 32, and the second delay resistor 36, so that the voltage is quickly discharged to a low level voltage. When the voltage of the first terminal of the delay capacitor 33 is lower than a low threshold voltage, the amplified output terminal of the operational amplifier 41 of the hysteresis module 4 outputs a high level voltage, so that the switch of the switch module 5 is electrically powered. The crystal 51 does not turn on and stops outputting the hot-swap power supply. As can be seen in FIG. 9, in practical applications, since the second terminal of the switching transistor 51 is electrically connected to the subsequent circuit, it can be regarded as electrically connected to a Large equivalent capacitance, although the switching transistor 51 is no longer conductive, but Voltage of the second terminal of the switch transistor 51 is still low level voltage will not fall immediately, but decreased slowly.

Referring to FIG. 1 and FIGS. 10 to 13, when the hot-swap device is repeatedly inserted and removed, the effects of the slow capacitor 33 and the delay diode 34 on slow charging and fast discharging can be clearly seen in FIG. 11, as shown in FIG. 13. It can be seen that the voltage of the second terminal of the switching transistor 51 will slowly decrease first due to the effect of the large equivalent capacitor. Then, after the hot plug device is inserted, the circuit on the hot plug device will instantly consume the large equivalent capacitor Residual charges on the capacitor are quickly reduced to a low level voltage, and after the switching transistor 51 is turned on, the hot-swap power supply (high level voltage) is output again.

Through the above description, the advantages of this embodiment can be summarized as follows:

First, by setting the detection module 2 to filter the connection signal, it can withstand unstable continuous surges caused by fast hot plugging and signal bounce, and by setting the delay module 3 to delay output, The effect of eliminating the signal surge can be achieved by the slow charging effect. By setting the hysteresis module 4, when the connection stable signal is higher than the high threshold voltage or lower than the low threshold voltage, the hysteresis module 4 outputs The switching signal will only change state, so it can effectively prevent misjudgment caused by noise such as jitter signals. With the above-mentioned multi-layer protection, it can effectively prevent component damage due to surges, noise, and jitter signals, so it can improve Service life, and can reduce misinterpretation of interference and improve the stability of operation.

2. By setting the delay capacitor 33 and designing a larger capacitance value of the delay capacitor 33, when the first delay transistor 31 is turned on after receiving the connection state signal, it takes a period of time to make the delay capacitor 33 The first terminal of the charger is charged to a high level voltage, so that the connection stabilization signal can be output after a delay. This is because the hot-swap device is prone to surge interference when it is just inserted into the connection. By delaying for a period of time, It can wait for the connection signal and the connection state signal to be stable before performing subsequent output, so it can avoid the subsequent circuits being misjudged or even damaged by the surge interference.

3. By setting the delay diode 34, when the hot-swap device is unplugged and disconnected, the voltage at the output terminal 22 of the detection module 2 returns to a high level, and the second delay transistor 32 is turned on. The delay capacitor 33 can be quickly discharged to the ground terminal GND through the delay diode 34, so the first terminal of the delay capacitor 33 can quickly return to a low level voltage, and the switch is enabled by the hysteresis module 4. The transistor 51 is non-conductive and stops outputting the hot-swap power supply, whereby the hot-swap circuit can quickly stop outputting the hot-swap power supply after the hot-swap device is unplugged.

4. By setting the second detection resistor 24 and the first switching resistor 52, the control terminal of the first delay transistor 31, the control terminal of the second delay transistor 32, and the switching transistor 51 can be provided. The voltage value preset at the control terminal prevents the voltage fluctuation of the control terminal of the first delay transistor 31, the control terminal of the second delay transistor 32, and the control terminal of the switching transistor 51 due to an idle connection, which causes abnormalities. Continuity or non-conduction leads to misjudgment.

In summary, it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made according to the scope of the patent application and the contents of the patent specification of the present invention are still Within the scope of the invention patent.

2‧‧‧ Detection Module

21‧‧‧Receiver

22‧‧‧output

23‧‧‧first detection resistor

24‧‧‧Second detection resistor

25‧‧‧detection capacitor

3‧‧‧ Delay Module

31‧‧‧First Delay Transistor

32‧‧‧second delay transistor

33‧‧‧ delayed diode

34‧‧‧First delay resistor

35‧‧‧second delay resistor

36‧‧‧ Delay capacitor

4‧‧‧ Hysteresis Module

41‧‧‧ Operational Amplifier

42‧‧‧The first hysteresis resistor

43‧‧‧second hysteresis resistance

44‧‧‧Third Hysteresis Resistor

45‧‧‧Fourth hysteresis resistance

5‧‧‧Switch Module

51‧‧‧Switching transistor

52‧‧‧The first switch resistance

53‧‧‧Second switch resistance

91 ~ 94‧‧‧ waveform

VCC‧‧‧Power terminal

GND‧‧‧ ground terminal

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is a circuit diagram of an embodiment of a hot-swap circuit of the present invention; and FIGS. A measurement waveform diagram of a hot-swap device when plugged in; Figures 6-9 are measurement waveform diagrams of the embodiment when the hot-swap device is removed; and Figures 10-13 are examples of the hot-swap device in the embodiment Measurement waveforms when the device is repeatedly inserted and removed.

Claims (10)

A hot-swap circuit is suitable for providing a hot-swap power source to a hot-swap device, and includes: a power terminal and a ground terminal; a detection module for receiving information related to whether the hot-swap device is A connected connection signal, and filtering the connection signal to output a connection status signal; a delay module electrically connected to the detection module, receiving the connection status signal, and delaying output of a stable connection according to the connection status signal Signals to eliminate signal surges; a hysteresis module, electrically connected to the delay module, receiving the connection stability signal, and outputting a switching signal after the hysteresis processing; and a switch module, electrically connected to the hysteresis module, Receive the switching signal, and output and not output the hot-swap power according to the switching signal. The hot-plug circuit according to claim 1, wherein the detection module includes a receiving end for receiving the connection signal, an output end for outputting the connection status signal, and two ends electrically connected to the receiving end respectively. A first detection resistor connected to the output terminal, and a detection capacitor electrically connected to the output terminal and the ground terminal at both ends. The hot-swap circuit according to claim 2, wherein the detection module further includes a second detection resistor electrically connected at both ends to the power terminal and the receiving terminal, respectively. The hot-swap circuit according to claim 1, wherein the delay module includes: a first delay transistor having a first terminal, a second terminal electrically connected to the power terminal, and a terminal for receiving the connection A control terminal of the status signal, a second delay transistor having a first terminal electrically connected to the second terminal of the first delay transistor, a second terminal electrically connected to the ground terminal, and a connection status signal The control terminal and a delay capacitor have a first terminal electrically connected to the second terminal of the first delay transistor and used to output the connection stable signal, and a second terminal electrically connected to the ground terminal. The hot-swap circuit according to claim 4, wherein the delay module further comprises: a delay diode electrically connected between the second terminal of the first delay transistor and the first terminal of the delay capacitor, And having an anode terminal electrically connected to the delay capacitor, a cathode terminal electrically connected to the first delay transistor, and a first delay resistor, both ends of which are electrically connected to the anode terminal of the delay diode and the cathode, respectively. extreme. The hot-swap circuit according to claim 5, wherein the delay module further includes a second delay resistor electrically connected between the second terminal of the second delay transistor and the ground terminal. The hot-swap circuit according to claim 1, wherein the hysteresis module includes: an operational amplifier having an inverting input terminal for receiving the connection stabilization signal, a forward input terminal, and an output terminal The amplified output terminal of the switching signal has a first hysteresis resistor having a first terminal electrically connected to the power source terminal, and a second terminal and a second hysteresis resistor having a second terminal electrically connected to the first hysteresis resistor. A first terminal, a second terminal electrically connected to the positive input terminal of the operational amplifier, a third hysteresis resistor, a first terminal electrically connected to the second terminal of the second hysteresis resistor, and an electrical amplifier electrically connected to the operational amplifier The second terminal of the amplified output terminal and a fourth hysteresis resistor have a first terminal electrically connected to the second terminal of the first hysteresis resistor and a second terminal electrically connected to the ground terminal. The hot-swap circuit according to claim 1, wherein the switch module includes a switching transistor having a first terminal electrically connected to the power terminal and a first terminal for outputting the hot-swap power source. Two terminals, and a control terminal for receiving the switching signal. The hot-swap circuit according to claim 8, wherein the switch module further includes a first switch resistor, the first switch resistor has a first terminal electrically connected to the power terminal, and a switch transistor electrically connected The second end of the control end. The hot-swap circuit according to claim 9, wherein the switch module further includes a second switching resistor electrically connected to the hysteresis module and the control terminal of the switching transistor at both ends, and the control terminal of the switching transistor. The switch signal is received via the second switch resistor.