JP2001228943A - Hot-swap controller - Google Patents

Abstract

(57) [Summary] [Problem] To suppress the generation of noise to other systems and the fluctuation of power supply during hot-swap. SOLUTION: In a block which receives power supply from a main part via a plug, a capacitor 2 for holding a precharge power supply, a first switch 4b for turning on / off a power supply to a predetermined internal circuit, and setting. A second switch 4a for turning on / off the operation of the element; and a precharge power supply, when connected to a plug, turns on the first switch first, and then turns on the second switch. A switch control circuit 5 for controlling driving is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for suppressing noise generation and fluctuations in power supply during hot-swap insertion / removal into / from an operating system.

[0002]

2. Description of the Related Art A hot-swap device inserts or removes a part of a circuit board while power is supplied to an operating system, which adversely affects system bus signals and power in other circuits. It is necessary to take countermeasures. There are two technical items for performing hot swapping. One is to suppress the noise by controlling the output of the bus signal, and the other is to consider that the system power supply does not fluctuate and other circuits do not malfunction. In other words, when the output of the bus signal is controlled and a new circuit board is inserted or removed from the operating bus, the output signal of the circuit board needs to be in an output stopped (high impedance) state. As a conventional technique, it is realized by output enable control of a tri-state buffer, control by a bus switch element and the like. In addition, as a measure against power supply noise, an inrush current flowing into a circuit board when a live line is inserted is suppressed, and disturbance (voltage drop) of the power supply is prevented. Conventional techniques include a method of connecting a resistor in series to a power supply line to suppress a sudden change in voltage, a method of supplying power from a power supply of another system, and the like.

As a first prior art, a hot-line insertion / extraction method shown in FIG. 7 is described in Japanese Patent Application Laid-Open No. 62-192814. According to this prior example, the insertion / extraction device mounts a power supply connector from a different path from the common bus of the device. At the time of insertion / removal, power is supplied to the bus signal output buffer from a separate system power supply, and the output of the buffer is stopped to prevent malfunction of the live-line system.

Further, as a second conventional technique, a hot-line insertion / extraction method shown in FIG. 8 is described in Japanese Patent Application Laid-Open No. 1-309108. According to this prior example, the insertion / extraction device is equipped with a holding power source such as a battery or a capacitor. At the time of insertion / removal, the bus signal output buffer is operated by the holding power supply, and the output of the buffer is stopped to prevent malfunction of the live-line system.

[0005]

The prior arts described above have the following problems. In order to supply power from a power supply of a different system from that of the common bus of the first conventional example, a power supply cable for hot-swap is required, and the device becomes complicated. In addition, there is a problem that the operator of hot-swapping and unplugging a cable needs to perform a work of attaching and detaching a cable according to a predetermined procedure. When using the battery of the second conventional example,
There is a problem in terms of maintenance because batteries need to be replaced periodically. In the second conventional example, a modified example in which a capacitor is used as a holding power supply is also described. However, this conventional technique is for stopping output of a bus signal, and takes into consideration an inrush current flowing into an insertion / extraction device. Absent. Therefore, there remains a problem that a sudden fluctuation occurs in the power supply of the system as a result of hot-swapping, which may cause a malfunction of the system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to suppress both the noise and the rapid fluctuation of the power supply to other systems due to hot-swap. [Detailed description of the invention]

[0007]

According to the present invention, there is provided a hot-swap controller according to the present invention, comprising: a block for receiving a power supply from a main unit via a plug; A first switch element for turning on / off a power supply, a second switch element for turning on / off a predetermined signal output, and a first switch when supplied with a precharge power supply and connected to a plug. A switch control circuit for turning on the element and subsequently driving and controlling the second switch element to be on was provided.

Further, the switch control circuit performs control so that the first switch element for turning on / off the power supply to the internal circuit is gradually turned on.

Furthermore, the internal circuit is divided into a plurality of circuits, and a plurality of first switch elements are provided correspondingly to form a first switch element group, and the switch control circuit is connected to a plug receiving power supply. Then, each switch element of the first switch element group is sequentially turned on with a shifted timing.

[0010] Furthermore, a detection pin physically connected last to the plug is provided, and the switch control circuit controls each switch to be ON by fitting the detection pin.

Further, a resistor is provided at a part of the power supply pin connected to the plug and receiving power supply from the main part.

Further, the types of pins to be connected to the plug are divided into a power pin and a signal pin, so that the power pin is connected to the plug before the signal pin.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An apparatus that suppresses both noise and sudden power supply voltage fluctuations will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a hot-swap controller for holding voltage of a circuit board by a capacitor according to the present embodiment. In the figure, a circuit board 1 is hot-plugged into and out of a system that is energized by a power supply 6 via a connector on a backplane 7. The connection / disconnection of the bus signal 7a from the backplane is controlled by the switch element 4a. The power supply of the circuit board 1 is switched between the precharge power supply V _pre and the internal circuit power supply V _int by the switch element 4b.
Is divided into The precharge power supply is held in voltage by the large-capacity capacitor 2, and the switch elements 4a,
Power is supplied to the switch control circuit 5 for controlling the switch 4b. The switch element 4b is usually a semiconductor switch (MOS
FET etc.) are used. The output of the switch control circuit 5 gradually reduces the ON resistance of the switch 4b by gently controlling the gate of the switch element 4b. Since the electrical connection between the V _pre power supply and the V _int power supply is gradually made, the influence of the power supply fluctuation outside the circuit board 1 is small. Note that the current suppressing resistor 3 connected to the + terminal of the capacitor 2 is for suppressing the current flowing from the backplane when the capacitor 2 is not charged.

Before the circuit board 1 is inserted, the switch elements 4a and 4b are kept OFF by the switch control circuit 5. As a result, the bus signal 7a is disconnected between the back plane 7 and the circuit board 1. Further, the precharge power supply and the internal circuit power supply are also in a disconnected state.

The operation of the circuit device having the above configuration will be described. When the circuit board 1 is connected to the backplane 7, the switch elements 4a and 4b are kept OFF by the switch control circuit 5 until the Card_Conn signal 7b is detected, so that the bus signal remains disconnected. is there. The power supply from the back plane is also performed only for the precharge power supply. Since the capacitor is charged in the precharge power supply, no new inrush current flows. That is, the capacitor is charged and there is a sufficient V _pre voltage, so that the switch control circuit 5 is ready to start operating immediately. When the circuit board 1 is inserted into the backplane 7, the physical configuration is such that the electrical contact of the pin 7b to GND is last in comparison with the pins of the other 7a and the like. Therefore, after that, the switch control circuit 5 detects the Card_Conn signal 7b after supplying power to the precharge power supply. When this detection is made, first, the switch element 4b is controlled to be ON. Thus, power is supplied to the internal circuit power supply of the circuit board. Thereafter, all the circuits on the circuit board 1 become operable, the switch element 4a is turned on, and the bus signal 7a is connected.

By the above operation, both the control for the bus signal 7a and the countermeasure against the power supply noise can be satisfied as the hot-swap device. In the same circuit configuration as above, the internal circuit power supply is divided into a plurality of parts, and a plurality of switch elements are provided between the precharge power supply corresponding to the respective internal circuit power supplies. On the other hand, the rush current flowing into the internal circuit power supply may be suppressed by sequentially controlling the ON state. By doing so, the fluctuation of V _cc due to the connection of V _int becomes more gentle.

A description will be given of a device for preventing a sudden fluctuation of the power supply that occurs when a live line is inserted after the circuit board 1 has been pulled out for a long time. That is, a configuration in which the precharge power supply can be charged as necessary before insertion will be described. FIG. 2 is a diagram showing the configuration. In FIG. 2, on the front panel of the circuit board 1,
A charge / voltage check terminal 8 for the capacitor 2 is provided. The voltage of the capacitor can be checked using the charging terminal 8, and charging can be performed in an off-line state if necessary.

Embodiment 2 FIG. In the present embodiment, a physical structure that guarantees the control mode of the above embodiment will be described. FIG. 3 shows a configuration for detecting the insertion of the circuit board 1 by a signal of two or more pins. The circuit configuration of the device is Card_C
It is the same as the first embodiment except for the structure of the onn signal 7b pin. According to the configuration of FIG.
The _Conn signal is detected according to an AND condition of completion of connection of the pins 7b1 and 7b2. The detection signal is detected when at least two or more (two in this example) physically separated connector pins are attached. When all the detection signals (7b1, 7b2) become significant in this way, the completion of the insertion of the device is confirmed.

In the first embodiment, the card connection detection pin 7
Although b has a short pin structure that makes electrical contact last, such a physical structure is not required in the present embodiment. That is, it is possible to perform hot-swap even in a system having a normal pin configuration.

Embodiment 3 Similar to the second embodiment, another structure for ensuring the control operation of the first embodiment will be described. According to the pin structure shown in FIG. 4 in the present embodiment, the connector 10b mounted on the circuit board 1 fits with the connector 10a on the backplane 7, but the receptacle 12 of the connector 10b And a conductor 122.

At the initial stage when the circuit board 1 is inserted into the back plane 7, the connector pins 11 and the connector receptacle 12 are connected via the resistor 121. Further insertion proceeds, and when the connector is completely fitted, the connector pin 11 comes into contact with the conductor portion 122. If a receptacle having the resistor portion 121 is used as a power supply pin, an inrush current prevention resistor as an independent component on the circuit board 1 is not required.

Another pin structure will be described with reference to FIG. In FIG. 5, the contacts of the connectors 10a and 10b are classified into those for power supply and those for signal. Connector pin 11b for power supply
The structure of the receptacle 12b is the same as that of FIG. The signal receptacle 12a has a short pin structure in which electrical contact is obtained after insertion proceeds more than the power receptacle.

In the initial stage of insertion, power is supplied to the circuit board 1 with the signal connector pins 11a disconnected. Since power is supplied through the resistor 121, the rush current is suppressed. Thereafter, the connector is completely fitted in a state where the circuit in the circuit board is sufficiently operable and the bus signal output is stopped by an internal reset signal or the like, and the signal connector pin 11a comes into contact with the receptacle 12a.

In the structure shown in FIG. 5, the short contact and the resistor 121 are respectively connected to the connector receptacles 12a and 12a.
b, but the connector receptacles 12a, 12
The same applies to a short pin structure in which the resistor portions are provided by devising the connector pins 11a and 11b instead of providing the resistor pins b.

FIG. 6 shows a further refinement of the pin structure of FIG. That is, the contact spring 13 is provided. The contact spring 13 is provided not on the connector receptacles 12a and 12b but on the connector pins 11a and 11b.

[0026]

According to the present invention, as a precharge power supply, a live line is inserted in a state where a voltage is held in advance by a large-capacity capacitor, and thereafter, a signal line is utilized. This has the effect of preventing not only the noise from being mixed into the signal line but also the occurrence of malfunction due to power supply fluctuation.

Further, the internal circuit power supply is separated into a plurality of parts, and control is performed such that the switching elements connecting each internal power supply and the precharge power supply are sequentially turned on, so that there is an effect of preventing a sudden power supply fluctuation.

Further, since the insertion detection of the circuit board is performed through the pin which makes the last electrical contact, there is an effect that the activation of the signal line is delayed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a hot-swap controller according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration of another hot-swap controller in the first embodiment.

FIG. 3 is a diagram showing a configuration of a hot-swap controller according to Embodiment 2 of the present invention.

FIG. 4 is a diagram showing an example of a plug structure according to Embodiment 3 of the present invention.

FIG. 5 is a diagram showing another example of a plug structure according to the third embodiment.

FIG. 6 is a diagram showing another example of a plug structure according to the third embodiment.

FIG. 7 is a diagram illustrating a hot-swap method according to a first conventional example.

FIG. 8 is a diagram for explaining a hot-swap method according to a second conventional example.

[Explanation of symbols]

2 Large capacity capacitor, 3 Current suppression resistor, 4a, 4b
Switch element, 5 switch control circuit, 7b, 7b1,
7b2 Card connection detection pin, 8 capacitor charge / voltage check terminal, 121 resistor.

Claims (6)

[Claims] 1. A block for receiving a power supply from a main unit via a plug, a capacitor for holding a precharge power supply, a first switch element for turning on / off a power supply to an internal circuit, and a predetermined signal. A second switch element for turning on / off an output; and when the precharge power is supplied and connected to the plug, the first switch element is turned on first, and then the second switch element is turned on. A hot-swap controller comprising a switch control circuit for driving and controlling the switch. 2. The switch according to claim 1, wherein the switch control circuit controls the first switch element for turning on / off the power supply to the internal circuit so that the first switch element is gradually turned on. Wire insertion control device. 3. The internal circuit is divided into a plurality of circuits, a plurality of first switch elements are provided correspondingly to form a first switch element group, and the switch control circuit is connected to a plug receiving power supply. 2. The hot-swap controller according to claim 1, wherein each of the switch elements of the first switch element group is sequentially turned on at a shifted timing. 4. A connector according to claim 1, wherein a detection pin physically connected last to said connector is provided, and said switch control circuit controls each switch element to be turned on by fitting said detection pin. Item 7. A control device for hot-swap according to Item 1. 5. The hot-swap controller according to claim 1, wherein a resistor is provided at a part of a power supply pin connected to the connector and receiving power from the main unit. 6. The type of a pin connected to a plug is divided into a power pin and a signal pin, and the power pin is connected to the plug before the signal pin. 2. The control device for hot-swap according to claim 1.