JP2006332304A - Semiconductor relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve photo sensitivity upon turn-on of an optical-coupling PNPN switch, and to prevent the deterioration of noise resistance upon turn-off, in a semiconductor relay device employing the optical-coupling PNPN switch. <P>SOLUTION: The semiconductor relay device 1a is equipped with: an LED (light emitting diode) 2a generating an optical signal L1 in accordance with an input signal S1; an optical switch 3 for output switching an AC power supply by receiving the optical signal L1 of the LED 2a; and an impedance circuit generating a voltage for putting the optical switch 3 on between a p-gate and a cathode. In such a semiconductor relay device 1a, the impedance circuit is constituted of a magnetic resistance element 4 changing a resistance value by the magnitude of an external magnetic field, and the resistance value of the magnetic resistance element 4 is controlled by a magnetic field generated by a magnetism generating means 5 both to improve optical sensitivity upon turn-on of the optical switch 3, and to prevent deterioration of noise resistance upon turn-off of the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor relay device used for switching of a load connected to an AC power source, and more particularly to a semiconductor relay device using an optical trigger thyristor that switches with an optical signal.

  The optical trigger thyristor is a reverse blocking thyristor that is directly ignited (triggered) by an optical signal, and is a three-terminal switching element that can be switched on and off by a slight optical signal gate input. The semiconductor relay device using this optical trigger thyristor can electrically insulate the main power circuit from the control circuit by using an optical signal, and is less susceptible to malfunction due to noise and has excellent noise resistance. Simplification is possible, and it is often used in high-voltage AC power supply circuits and the like.

  In recent years, in such a semiconductor relay device, as the thyristor has a higher withstand voltage and a larger capacity, it is highly sensitive to an input signal, and further due to a change in applied voltage between the anode and the cathode in the forward blocking state. It is desired that the tolerance to erroneous firing is large and that malfunction due to noise or the like does not occur.

  An example of this type of conventional semiconductor relay device is shown in FIG. The semiconductor relay device 100 includes an optically coupled PNPN switch (hereinafter abbreviated as an optical switch) 102 of a reverse blocking three-terminal light-igniting thyristor having a PNPN four-layer structure, and a light emitting diode (LED) that sends a light control signal to a gate. 101. The optical switch 102 includes a PNP transistor and an NPN transistor as shown in the equivalent circuit of FIG. When receiving light from the LED 101 on the input side, the optical switch 102 generates a photocurrent (Ipnp) at the PN junction between the P gate and the N gate. This photocurrent (Ipnp) causes a current to flow through the short-circuit resistance (Rgk) 103 between the gate and the cathode, and a terminal voltage (Vgk = Ipnp × Rgk) is generated in the short-circuit resistance 103. When this inter-terminal voltage becomes a voltage large enough to operate the NPN transistor Tr2 (hereinafter simply referred to as Tr2), Tr2 is turned on, and then the transistor Tr1 (hereinafter simply referred to as Tr1) is turned on. As a result, the anode and the cathode are electrically connected (turned on). That is, the optical switch 102 shifts from the forward blocking state to the forward conducting state, and performs a light control switching operation. Therefore, if the resistance value of the short-circuit resistor 103 is large, conduction is accelerated and the photosensitivity is improved.

  On the other hand, when a sharply rising voltage is applied between the anode and cathode of the PNPN element in the optical switch 102 when the power is turned on, a displacement current due to a transient current is generated in the junction capacitance of each PN junction. To do. This displacement current is an unnecessary noise current, and flows through the short-circuit resistor 103 to generate a terminal voltage (Vgk), causing the optical switch 102 to malfunction (turn on). In order to prevent this malfunction, it is necessary to improve the dV / dt tolerance against malfunction caused by noise or the like (resistance against malfunction due to a change in the applied voltage between the anode and the cathode in the forward blocking state). In order to improve the dV / dt resistance, reducing the resistance value of the short-circuit resistor 103 is an effective means. However, if the resistance value of the short-circuit resistor 103 is reduced, the photosensitivity is adversely affected.

  As described above, in the semiconductor relay device 100 using the conventional optical switch 102, there has always been a contradictory relationship between improvement in optical sensitivity and reduction in malfunction due to noise.

  As a conventional example proposed to eliminate such a relationship, a process for depositing impurities in the wiring material is performed in the wiring portion in the semiconductor layer that includes the false firing light prevention circuit and forms the optically coupled PNPN switch. There is known a semiconductor relay device in which the resistance of the wiring portion is reduced to increase the sensitivity (see, for example, Patent Document 1).

However, this conventional example requires a separate semiconductor element for the false firing light prevention circuit and also requires a process of depositing impurities in the wiring material to improve the photosensitivity, complicating the semiconductor process, etc. There was a problem.
JP-A-5-75108

  The present invention has been made to solve the above-described problem, and uses a magnetoresistive element whose resistance value changes depending on the magnitude of external magnetism as an impedance circuit between the gate and the cathode of an optically coupled PNPN switch. By controlling the resistance value of this magnetoresistive element with an external magnetic field generated by the magnetism generating means, it is possible to improve both the photosensitivity at the time of turn-on of the optically coupled PNPN switch and prevent the reduction of the noise tolerance at the time of turn-off. An object of the present invention is to provide a semiconductor relay device that can perform the above-described operation.

  In order to achieve the above object, a first aspect of the present invention is a light emitting element that generates an optical signal in response to an input signal, and an optically coupled PNPN switch for output that switches an AC power supply in response to the optical signal of the light emitting element. And an impedance circuit for generating a voltage for turning on the optically coupled PNPN switch between the P-gate and the cathode of the optically coupled PNPN switch, This comprises a magnetoresistive element whose resistance value varies depending on the size of.

  According to a second aspect of the present invention, in the semiconductor relay device according to the first aspect of the present invention, the semiconductor relay device includes a magnetic generation unit that is magnetically coupled to the magnetoresistive element and generates a magnetic field for controlling the magnetoresistive element. A circuit through which a current for generating a magnetic field of the generating means flows and a circuit through which a current for generating an optical signal of the light emitting element is connected in series.

  According to a third aspect of the present invention, in the semiconductor relay device according to the first aspect of the present invention, the semiconductor relay device includes a magnetic generation unit that is magnetically coupled to the magnetoresistive element and generates a magnetic field for controlling the magnetoresistive element. The generating means has a light receiving element that receives the light signal of the light emitting element and generates power, and generates a magnetic field by the power generation of the light receiving element.

  According to a fourth aspect of the present invention, there is provided a light emitting element that generates an optical signal in response to an input signal, an output optically coupled PNPN switch that receives an optical signal from the light emitting element and switches an AC power supply, and the optically coupled PNPN. A semiconductor relay device comprising an impedance circuit for generating a voltage for turning on a switch between a P gate and a cathode of the optically coupled PNPN switch, and in parallel with the impedance circuit, a P gate of the optically coupled PNPN switch. And a depletion type P-channel MOSFET whose drain and source are connected to the cathode, and the resistance value varies depending on the magnitude of the magnetic field applied between the gate of the P-channel MOSFET and the N gate of the optically coupled PNPN switch. The magnetoresistive element to be connected is connected.

  According to a fifth aspect of the present invention, in the semiconductor relay device according to the fourth aspect of the present invention, the semiconductor relay device includes magnetic generation means for magnetically coupling with the magnetoresistive element and generating a magnetic field for controlling the magnetoresistive element. A circuit through which a current for generating a magnetic field of the generating means flows and a circuit through which a current for generating an optical signal of the light emitting element is connected in series.

  A sixth aspect of the present invention is the semiconductor relay device according to the fourth aspect, further comprising: a magnetic generating means that is magnetically coupled to the magnetoresistive element and generates a magnetic field for controlling the magnetoresistive element, The magnetic field generated by the magnetic generation means and the optical signal generated by the light emitting element are generated by the same current.

  According to the first aspect of the present invention, the impedance circuit between the P gate and the cathode of the optically coupled PNPN switch (hereinafter abbreviated as an optical switch) is provided with a magnetoresistive element, so that the impedance of the impedance circuit itself can be reduced by an external magnetic field. Easy to control. As a result, the impedance of the magnetoresistive element is controlled to be large when the optical switch is on and small when the optical switch is off, thereby improving the photosensitivity when the switch is turned on and preventing the reduction of noise tolerance when the switch is turned off. Can be realized easily. Further, since the impedance can be controlled independently only by controlling the magnetic field from the outside without affecting other circuits, the impedance can be controlled very easily.

  According to the invention of claim 2, since the current for generating the magnetic field in the magnetism generating means and the current for generating the optical signal in the light emitting element can be made the same, in conjunction with the on / off of the optical switch by the optical signal, The impedance of the magnetoresistive element due to the magnetic field can be increased or decreased, and the timing of impedance control can be synchronized. Therefore, it is possible to efficiently and surely improve the photosensitivity when the optical switch is on and prevent the reduction of the noise tolerance when the switch is off. In addition, since the magnetism generating means does not require a power supply circuit and the light emitting element and the magnetism generating means can be integrated, power saving and space saving can be achieved.

  According to the invention of claim 3, since the magnetic field of the magnetism generating means is generated by the power generation of the light receiving element that receives the optical signal, the magnetoresistive element can be made larger or smaller in synchronization with the on / off of the optical switch. Therefore, it is possible to reliably achieve both improvement in photosensitivity and prevention of reduction in noise tolerance. Further, no power supply is required for the magnetism generating means, and power saving and space saving can be achieved. Furthermore, since the light emitting element, the electromagnetic coil, and the magnetoresistive element are coupled by optical coupling or magnetic field coupling, and each can be spatially separated and independently arranged, the degree of freedom in device design can be further increased.

  According to the invention of claim 4, a depletion type P-channel MOSFET (hereinafter abbreviated as MOSFET) is connected in parallel to the impedance circuit, and the gate of the MOSFET and the N gate of the optical switch are connected by a magnetoresistive element. Thus, the MOSFET can be easily turned on and off by controlling the resistance of the magnetoresistive element with an external magnetic field. Therefore, if the resistance of the impedance circuit is increased, the impedance value between the P gate and the cathode can be accurately varied greatly. Thereby, the noise sensitivity can be prevented from being lowered, and the photosensitivity can be improved. Further, since the resistance of the magnetoresistive element can be varied independently by an external magnetic field, the on / off control of the MOSFET can be facilitated.

  According to the invention of claim 5, since the current for generating the magnetic field in the magnetism generating means and the current for generating the optical signal in the light emitting element can be generated with the same current, the switching of the optical switch by the optical signal and the magnetic field The switching operation of the MOSFET can be simultaneously performed in conjunction with each other. Therefore, the impedance can be reliably varied in synchronization with the on / off of the optical switch, and both the improvement of the photosensitivity and the prevention of the noise tolerance can be achieved. In addition, a power supply circuit is not required for the magnetism generating means, and the light emitting element and the magnetism generating means can be integrated, thereby saving power and space.

  According to the invention of claim 6, since the magnetic field of the magnetism generating means is generated by the power generation of the light receiving element that receives the optical signal, the optical switch is turned on and off by the optical signal, the MOSFET is turned on and off, and the P gate.・ Switching of impedance between cathodes can be linked simultaneously. As a result, it is possible to reliably improve the photosensitivity when the optical switch is on and prevent the noise tolerance from being lowered when the switch is off. Further, it is not necessary to supply power to the magnetism generating means, and power saving and space saving can be achieved. Further, the light emitting element, the magnetism generating means, and the magnetoresistive element that are optically or magnetically coupled to each other can be spatially separated, and the degree of freedom in device design can be increased.

  Hereinafter, a semiconductor relay device according to a first embodiment of the present invention will be described with reference to FIG.

  The semiconductor relay device 1a receives an optical signal L1 from the light emitting unit 2 having a light emitting diode LED (light emitting element) 2a that generates an optical signal L1 in response to an input signal S1, an magnetoresistive element 4, and an optical signal L1 from the LED 2a. And an output optically coupled PNPN switch (hereinafter abbreviated as an optical switch) 3.

  The optical switch 3 is a normal reverse blocking three-terminal thyristor having a PNPN four-layer structure so that the control signal to the gate shifts from the forward blocking state to the forward conducting state by irradiating the optical signal instead of the electric signal. This is a light ignition type thyristor constructed.

  The optical switch 3 comprising this light-igniting thyristor includes a PNP transistor Tr1 and an NPN transistor Tr2, the emitter side of Tr1 being an anode, the intersection of the collector of Tr1 and the base of Tr2 being a P gate, and the base of Tr1 being The intersection of the Tr2 and the collector is configured as an N gate, and the emitter side of the transistor Tr2 is configured as a cathode.

This semiconductor relay device 1a includes a magnetoresistive element 4 as an impedance circuit short-circuited between the P gate and the cathode of the optical switch 3, and a magnetic field coupled to the magnetoresistive element 4 for controlling the magnetoresistive element 4. And a magnetic generation means 5 for generating a magnetic field. When the optical signal generated by the LED 2a by the input signal S1 is received by the optical switch 3, a photocurrent (Ipnp) is generated at the PN junction between the P gate and the N gate. This photocurrent (Ipnp) causes a current to flow through the magnetoresistive element 4 serving as a short-circuit resistance between the P gate and the cathode. If the resistance of the magnetoresistive element 4 at this time is Rm, a voltage between terminals (Vm = Ipnp × Rm) is generated. When this inter-terminal voltage becomes a voltage large enough to operate TR2, Tr2 is turned on, and then Tr1 is turned on to conduct (turn on) between the anode and the cathode. That is, the optical switch 3 is shifted from the forward blocking state to the forward conducting state, and performs a light control switching operation.

Here, the impedance between the P gate and the cathode is represented by Z. In this semiconductor relay device 1a, the impedance circuit connected between the P gate and the cathode is the same as the resistance (Rm) of the magnetoresistive element 4, and is the same as the impedance Z.

  The magnetoresistive element 4 is composed of a variable resistance element (for example, an MR (Magneto Resistive) effect element) whose resistance value changes depending on the magnitude of the applied magnetic field, and is connected between the P gate and the cathode of the optical switch 3. Here, the magnetoresistive element 4 has a characteristic that the resistance value increases as the applied magnetic field increases. The magnetoresistive element 4 is magnetically coupled to the magnetism generating means 5, and the magnitude of the resistance is controlled by the magnetic field generated by the magnetism generating means 5. The

  In the above configuration, in the light emitting unit 2, a current is supplied to the LED 2a through the circuit 21 in response to the input signal S1, and an optical signal is generated. The optical switch 3 receives the generated optical signal L1 and turns on. At this time, in the magnetism generating means 5, a magnetic field is generated by the control input signal S2, and this magnetic field is applied to the magnetoresistive element 4 to increase its resistance value. Further, when the optical switch 3 is turned off, the resistance value is decreased.

  As described above, since the magnetoresistive element 4 can be directly varied by the external magnetic field, the impedance Z itself between the P gate and the cathode of the optical switch 3 can be directly and easily controlled. Therefore, when the switch is on, the impedance Z can be easily increased, and when the switch is off, the impedance Z can be easily reduced. This improves the photosensitivity when the switch is on, and prevents a reduction in noise tolerance when the switch is off. it can. Further, since the impedance Z can be controlled independently without affecting other electronic circuits only by controlling the magnetic field, the circuit control of the impedance between the P gate and the cathode can be easily performed. Furthermore, since the magnetoresistive element and the magnetism generating means are magnetically coupled, the two can be spatially separated, and the degree of freedom in circuit layout design can be increased.

  Next, a semiconductor relay device according to a second embodiment of the present invention will be described with reference to FIG. The semiconductor relay device 1b according to the present embodiment includes a magnetic generation means 5 having an electromagnetic coil 5a that is magnetically coupled to the magnetoresistive element 4, and generates a light signal L1 and a circuit 51 through which the current of the electromagnetic coil 5a that generates a magnetic field flows. This is different from the above embodiment in that the circuit 21 through which the current of the light emitting element 2a to be flowed is connected in series.

  The semiconductor relay device 1b includes a light emitting unit 2 including a light emitting diode LED 2a that generates an optical signal L1 in response to an input signal S1, and an output optically coupled PNPN that receives the optical signal L1 from the LED 2a and switches an AC power source. A switch (hereinafter abbreviated as an optical switch) 3, a magnetoresistive element 4 as an impedance circuit for generating a voltage for turning on the optical switch 3 between the P gate and the cathode, and an electromagnetic coil connected in series to the LED 2a It is comprised with the magnetic generation means 5 which has 5a. The magnetoresistive element 4 is the same as that in the first embodiment.

  In the above configuration, when the optical signal L1 generated by the LED 2a in response to the input signal S1 to the light emitting unit 2 is received by the optical switch 3, the optical switch 3 is turned on. At the same time, a magnetic field is generated from the electromagnetic coil 5a connected in series with the LED 2a through which the current of the optical signal flows. By applying this magnetic field to the magnetoresistive element 4, the resistance value can be increased. When the LED 2a is turned off, the current is cut off, and the optical signal is lost, the optical switch 3 is turned off. At the same time, the magnetic field of the electromagnetic coil 5a is lost, and the resistance value of the magnetoresistive element 4 can be lowered.

  Here, since the LED 2a and the electromagnetic coil 5a are connected in series, the current of the optical signal L1 and the current of the magnetic field are the same. Therefore, on / off of the optical switch 3 by the optical signal L1 and control of the resistance value of the magnetoresistive element 4 by the magnetic field can be performed at a synchronized timing. As a result, when the optical switch 3 is on, the impedance Z is increased to improve the photosensitivity, and when the switch is off, the impedance Z can be reduced to prevent a reduction in noise immunity, thereby ensuring both characteristics. It can be performed with high accuracy. In addition, the power source of the electromagnetic coil 5a is not required, and the light emitting unit 2 and the electromagnetic coil 5a can be integrated, so that power saving and space saving can be achieved.

  Next, a semiconductor relay device according to a third embodiment of the present invention will be described with reference to FIG. The semiconductor relay device 1c of the present embodiment is different from the above-described embodiment in that the magnetic generator 5 having the electromagnetic coil 5b includes the light receiving element 6 and generates a magnetic field by power generation of the light receiving element 6 that receives the optical signal L2. Yes.

  The semiconductor relay device 1c includes a light emitting unit 2 having an LED (light emitting element) 2a that generates an optical signal L1 in response to an input signal S1, and an optical coupling for output that receives the optical signal L1 from the LED 2a and switches an AC power source. Type PNPN switch (hereinafter abbreviated as an optical switch) 3, a magnetoresistive element 4 as an impedance circuit for generating a voltage for turning on the optical switch 3 between the P gate and the cathode, and an optical signal L2 from the LED 2a. A light receiving element 6 that generates electric power and a magnetic generating means 5 having an electromagnetic coil 5b that generates a magnetic field by a current from the light receiving element 6. The magnetoresistive element 4 is the same as that in the first embodiment.

  The light receiving element 6 receives the optical signal L2 generated simultaneously with the optical signal L1 of the LED 2a and generates power. The electromagnetic coil 5b generates a magnetic field for controlling the magnetoresistive element 4 by the generated power. By applying the generated magnetic field to the magnetoresistive element 4, the resistance value of the magnetoresistive element 4 can be controlled.

  In the above configuration, when the optical signal L1 generated by the LED 2a in response to the input signal S1 to the light emitting unit 2 is received by the optical switch 3, the optical switch 3 is turned on. At the same time, the light signal L2 generated in the LED 2a is received by the light receiving element 6. The light receiving element 6 generates electric power by converting the received optical signal L2 into an electric signal. Using this generated power as a power source, a magnetic field is generated from the electromagnetic coil 5b. The generated magnetic field increases the resistance value of the magnetoresistive element 4 coupled with the electromagnetic coil 5b. Next, when the LED 2a is turned off and the current is cut off, and the optical signals L1 and L2 are lost, the optical switch 3 is turned off. At the same time, the magnetic field is lost, so that the resistance value of the magnetoresistive element 4 can be reduced.

  In this way, the timing of control of the on / off state of the optical switch 3 and the resistance value (same as the impedance Z) of the magnetoresistive element 4 can be synchronized by the simultaneously generated optical signals L1 and L2. Accordingly, when the optical switch 3 is turned on, the impedance Z of the magnetoresistive element 4 is increased to improve the photosensitivity, and when the switch is turned off, the impedance Z of the magnetoresistive element 4 is decreased to prevent a reduction in noise tolerance. can do. Further, since the LED 2a, the electromagnetic coil 5b optically coupled to the LED 2a, and the magnetoresistive element 4 magnetically coupled to the electromagnetic coil 5b can be spatially separated, the degree of freedom in device design can be increased.

  Next, a semiconductor relay device according to a fourth embodiment of the present invention will be described with reference to FIG. The semiconductor relay device 1d of this embodiment is provided with a resistor 7 (impedance circuit) between a P gate and a cathode of an optically coupled PNPN switch (hereinafter abbreviated as an optical switch) 3, and a depletion type in parallel with the resistor 7. A P-channel MOSFET (hereinafter abbreviated as a MOSFET) 8 is connected, and the gate of this MOSFET 8 and the N gate of the optical switch 3 are connected via a magnetoresistive element 9.

  The semiconductor relay device 1d is connected in parallel to the optical switch 3, the light emitting unit 2 having an LED (light emitting element) 2a that generates the optical signal L1 in response to the input signal S1, the resistor 7 serving as an impedance circuit, and the resistor 7. MOSFET 8, a magnetoresistive element 9 serving as a bias resistance of MOSFET 8, and magnetism generating means 5 magnetically coupled to the magnetoresistive element 9.

  The optical switch 3 includes a PNP transistor Tr1 and an NPN transistor Tr2. The emitter side of Tr1 is an anode, the intersection of the collector of Tr1 and the base of Tr2 is a P gate, and the intersection of the base of Tr1 and the collector of Tr2 is an N gate. The emitter side of the transistor Tr2 is configured as a cathode.

  Between the P gate and the cathode of the optical switch 3, a resistor 7 for generating a voltage for turning on the optical switch 3 and a drain and a source of the MOSFET 8 are connected in parallel with the resistor 7. At the same time, the drain and source are connected to the P gate and cathode of the optical switch 3, respectively. Further, a magnetoresistive element 9 serving as a gate bias resistance of the MOSFET 8 is connected between the gate of the MOSFET 8 and the N gate of the optical switch 3.

  The magnetoresistive element 9 has a characteristic that the resistance value decreases as the applied magnetic field increases. The magnetoresistive element 9 is magnetically coupled to the magnetism generating means 5 that generates a magnetic field by the control input signal S2, and the magnitude of the resistance of the magnetoresistive element 9 is controlled by the magnetic field. Here, the impedance Z between the P gate and the cathode of the optical switch 3 is the impedance of the parallel combination of the resistor 7 and the MOSFET 8.

  In the above configuration, when the optical switch 3 is turned on, a magnetic field is generated by the magnetic generation means 5 by the control input signal S2, and the resistance value of the magnetoresistive element 9 is reduced by this magnetic field. As a result, the gate voltage of the MOSFET 8 is raised and the MOSFET 8 is turned off (open). The impedance of the MOSFET 8 increases rapidly, and the impedance Z between the P gate and the source is determined by the resistor 7.

  Next, when the optical switch 3 is turned off, the resistance value of the magnetoresistive element 9 is increased by reducing the magnetic field of the magnetism generating means 5. Therefore, the MOSFET 8 can be turned on, and the impedance Z between the P gate and the source is short-circuited and becomes a low impedance of substantially zero. Thus, if the value of the resistor 7 is increased, the change in the impedance Z between the gate and the source when the MOSFET 8 is turned on / off can be greatly increased.

Thus, when the optical switch 3 is on, the impedance Z can be increased by reducing the resistance of the magnetoresistive element 9 and turning off the MOSFET 8. Similarly, when the optical switch 3 is off, the resistance of the magnetoresistive element 9 can be increased to turn on the MOSFET 8 and the impedance Z can be reduced. As a result, the optical sensitivity when the optical switch 3 is on can be improved, and a reduction in noise tolerance can be prevented when the optical switch 3 is off. Further, since the switching operation of the MOSFET 8 can be performed with an independent magnetic field strength, the MOSFET 8 can be easily controlled.

  Next, a semiconductor relay device according to a fifth embodiment of the present invention will be described with reference to FIG. The semiconductor relay device 1e according to the present embodiment includes a magnetic generator 5 having an electromagnetic coil 5c that is magnetically coupled to the magnetoresistive element 9, and generates an optical signal L1 and a circuit 51 through which a current flows in the electromagnetic coil 5c that generates a magnetic field. This embodiment is different from the above-described embodiment in that the current-carrying circuit 51 of the light-emitting element 2a is connected in series.

  The semiconductor relay device 1e includes a light emitting unit 2 having an LED 2a that generates an optical signal L1 in response to an input signal S1, an optical switch 3 for output that receives an optical signal L1 from the LED 2a, and switches an AC power source. A resistor 7 (impedance circuit) for generating a voltage for turning on the switch 3 between the P gate and the cathode of the optical switch 3 is connected in parallel to the resistor 7 and is connected between the P gate and the cathode of the optical switch 3. MOSFET 8, magnetoresistive element 9 connecting the gate of MOSFET 8 and N gate of optical switch 3, and electromagnetic coil 5 c that is magnetically coupled to magnetoresistive element 9 and generates a magnetic field with the same current as the current flowing in LED 2 a. It consists of. The magnetoresistive element 9 is the same as that in the fourth embodiment.

  The magnetoresistive element 9 is magnetically coupled to the electromagnetic coil 5c, and the electromagnetic coil 5c is connected in series to the LED 2a. Thereby, the current for generating the magnetic field of the electromagnetic coil 5c and the current for generating the optical signal of the LED 2a become the same current, and the resistance value of the magnetoresistive element 9 is controlled in conjunction with the light emission of the LED 2a.

  In the above configuration, when the LED 2a emits light, the optical signal L1 is received by the optical switch 3 and the optical switch 3 is turned on, a magnetic field is generated in the electromagnetic coil 5c in synchronization with this, and the resistance of the magnetoresistive element 9 The value becomes smaller. On the other hand, when the light emission of the LED 2a is stopped and the optical switch 3 is turned off, the magnetic field disappears at the same time, and the resistance value of the magnetoresistive element 9 increases. Thus, the MOSFET 8 is turned off and on in synchronization with the light emission of the LED 2a.

  In this way, the MOSFET can be turned off and on by controlling the resistance value of the magnetoresistive element 9 in conjunction with the switch on and off of the optical switch 3, and the impedance Z can be largely switched. As a result, it is possible to reliably improve the photosensitivity when the switch is on, and to prevent a reduction in noise tolerance when the switch is off. Further, since the magnetoresistive element 9 can be controlled from a spatially separated position, the MOSFET 8 can be easily controlled and the degree of freedom in design can be increased.

  Next, a semiconductor relay device according to a sixth embodiment of the present invention will be described with reference to FIG. The semiconductor relay device 1f according to the present embodiment includes a light receiving element 6 that generates power by receiving an optical signal L2 from an LED (light emitting element) 2a in a magnetism generating means 5 having an electromagnetic coil 5d. This is different from the above embodiment in that

  The semiconductor relay device 1f includes a light emitting unit 2 having an LED 2a that generates an optical signal L1 in response to an input signal S1, an output optical switch 3 that receives the optical signal L1 from the LED 2a and switches an AC power supply, and the light A resistor 7 (impedance circuit) for generating a voltage for turning on the switch 3 between the P gate and the cathode and the resistor 7 are connected in parallel, and a drain and a source are connected to the P gate and the cathode of the optical switch 3. A depletion type P-channel MOSFET (hereinafter abbreviated as MOSFET) 8, a magnetoresistive element 9 connecting the gate of the MOSFET 8 and the N gate of the optical switch 3, and a light receiving element 6 that receives the optical signal L2 from the LED 2a and generates power. And magnetic generation means 5 including an electromagnetic coil 5d that generates a magnetic field by this power generation.The magnetoresistive element 9 is the same as that in the fourth embodiment.

  The light receiving element 6 receives the optical signal L2 generated simultaneously with the optical signal L1 of the LED 2a and generates power. The electromagnetic coil 5d generates a magnetic field for controlling the magnetoresistive element 9 by the generated power. The generated magnetic field is applied to the magnetoresistive element 9 to control the resistance value of the magnetoresistive element 9.

  In the semiconductor relay device 1f, on / off of the optical switch 3, on / off of power generation of the light receiving element 6, and off / on of the MOSFET 8 can be linked by optical signals L1, L2 generated by the LED 2a. . By turning the MOSFET 8 off and on, the impedance Z between the P gate and the source of the optical switch can be changed from a resistor R having a large resistance value to a substantially short circuit.

  Thereby, when the optical switch 3 is turned on, the impedance Z between the P gate and the source is increased to increase the photosensitivity, and when the optical switch 3 is turned off, the impedance Z is decreased to improve the noise tolerance. Moreover, since the light emitting part 2 including the LED 2a, the magnetic light emitting means 5 including the electromagnetic coil 5d, and the magnetoresistive element 9 are coupled by light or a magnetic field, they can be arranged spatially apart from each other. The degree of freedom in device design can be increased.

  As described above, according to the semiconductor relay devices 1a to 1f according to the present embodiment, by providing the magnetoresistive element 4 in the impedance circuit between the P gate and the cathode of the optical switch 3, the impedance Z itself is changed to the external magnetic field. Can be easily controlled. Thereby, when the optical switch 3 is turned on, the impedance Z can be increased to improve the photosensitivity, and when the optical switch 3 is turned off, the impedance Z can be reduced to prevent the noise tolerance from being lowered. Further, since the impedance Z can be controlled independently only by the control by the magnetic field without affecting other circuits, the impedance control circuit design can be facilitated. Furthermore, since the magnetism generating means 5 that is magnetically coupled to the magnetoresistive element 4 can be spatially separated and arranged, the degree of freedom in device design including the circuit arrangement of the magnetism generating means 5 can be increased.

  In addition, by making the current that generates the magnetic field of the electromagnetic coil the same as the current that generates the optical signal of the LED, the switch of the optical switch by the optical signal and the impedance control of the magnetoresistive element by the magnetic field are linked and synchronized. The control timing accuracy is improved. As a result, it is possible to reliably achieve both improvement in photosensitivity when the switch is turned on and prevention of reduction in noise tolerance when the switch is turned off.

  Further, since the light emitting element, the electromagnetic coil, and the magnetoresistive element are connected by optical coupling or magnetic field coupling, each can be spatially separated and independently arranged, and the degree of freedom in device design can be increased.

  Further, by connecting a MOSFET in parallel with the impedance circuit and connecting a magnetoresistive element as a gate bias resistor between the gate of the MOSFET and the N gate of the optical switch, the MOSFET can be easily turned on and off by magnetic field control. If the resistance value of the impedance circuit is increased, the difference in impedance between the P gate and the source during on and off can be increased. As a result, it is possible to reliably improve the photosensitivity when the switch is on and to prevent a reduction in noise tolerance when the switch is off. Further, since the magnetoresistive element can be controlled from a spatially separated position, the MOSFET can be easily controlled, and the degree of freedom in device design is increased.

  Furthermore, by obtaining the current of the magnetism generating means from the current source of the light emitting element or the power generation using the optical signal, the magnetic field of the electromagnetic coil is generated in synchronization with the optical switch operation by the optical signal. By controlling the impedance, the MOSFET can be turned on and off in conjunction with each other. Accordingly, it is possible to improve the photosensitivity when the switch is turned on and to reliably prevent the noise tolerance from being lowered when the switch is turned off.

The block diagram of the semiconductor relay apparatus which concerns on the 1st Embodiment of this invention. The block diagram of the semiconductor relay apparatus which concerns on the 2nd Embodiment of this invention. The block diagram of the semiconductor relay apparatus which concerns on the 3rd Embodiment of this invention. The block diagram of the semiconductor relay apparatus which concerns on the 4th Embodiment of this invention. The block diagram of the semiconductor relay apparatus which concerns on the 5th Embodiment of this invention. The block diagram of the semiconductor relay apparatus which concerns on the 6th Embodiment of this invention. (A) is a block diagram of a conventional semiconductor relay device, (b) is an equivalent circuit diagram on the PNPN layer side of (a).

Explanation of symbols

1a to 1f Semiconductor relay device 2a LED (light emitting element)
3 Optical switch (Optically coupled PNPN switch)
4 Magnetoresistive element (impedance circuit)
5 Magnetic generating means 5a to 5d Electromagnetic coil (magnetic generating means)
6 Light receiving element 7 Resistance (impedance circuit)
8 MOSFET (depletion type P-channel MOSFET)
9 Magnetoresistive element L1 Optical signal S1 Input signal

Claims (6)

A light emitting element that generates an optical signal according to an input signal, an output optically coupled PNPN switch that receives an optical signal from the light emitting element and switches an AC power source, and a voltage for turning on the optically coupled PNPN switch In a semiconductor relay device comprising: an impedance circuit for generating a current between a P gate and a cathode of the optically coupled PNPN switch;
The semiconductor relay device according to claim 1, wherein the impedance circuit includes a magnetoresistive element whose resistance value varies depending on the magnitude of the applied magnetic field. Magnetic generation means for generating a magnetic field for magnetically coupling to the magnetoresistive element and controlling the magnetoresistive element;
2. The semiconductor relay device according to claim 1, wherein a circuit through which a current for generating a magnetic field of the magnetic generation unit flows and a circuit through which a current for generating an optical signal of the light emitting element is connected in series. Magnetic generation means for generating a magnetic field for magnetically coupling to the magnetoresistive element and controlling the magnetoresistive element;
2. The semiconductor relay device according to claim 1, wherein the magnetism generating unit includes a light receiving element that receives an optical signal of the light emitting element to generate electric power, and generates a magnetic field by the electric power generation of the light receiving element. A light emitting element that generates an optical signal according to an input signal, an output optically coupled PNPN switch that receives an optical signal from the light emitting element and switches an AC power source, and a voltage for turning on the optically coupled PNPN switch In a semiconductor relay device comprising: an impedance circuit for generating a current between a P gate and a cathode of the optically coupled PNPN switch;
In parallel with the impedance circuit, a depletion type P-channel MOSFET in which a drain and a source are connected to a P gate and a cathode of the optically coupled PNPN switch,
A semiconductor relay device, wherein a magnetoresistive element whose resistance value varies depending on the magnitude of an applied magnetic field is connected between the gate of the P-channel MOSFET and the N gate of the optically coupled PNPN switch. Magnetic generation means for generating a magnetic field for magnetically coupling to the magnetoresistive element and controlling the magnetoresistive element;
5. The semiconductor relay device according to claim 4, wherein a circuit through which a current for generating a magnetic field in the magnetism generating means flows and a circuit through which a current for generating an optical signal in the light emitting element flows are connected in series. Magnetic generation means for magnetically coupling with the magnetoresistive element and generating a magnetic field for controlling the magnetoresistive element;
5. The semiconductor relay device according to claim 4, wherein the magnetism generating unit has a light receiving element that receives an optical signal of the light emitting element and generates electric power, and generates a magnetic field by the electric power generation of the light receiving element.

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