Wide-band gap photo relay

Abstract

To provide a wide-band gap photo relay capable of improving an off-state voltage and a switching speed.SOLUTION: A wide-band gap photo relay comprises: first and second input terminals; first and second output terminals; a ground terminal; a light source; a photodiode array; and a depletion type wide-band gap semiconductor switch. The light source generates a light signal, includes a first end and a second end that are connected to the first and second input terminals. The photodiode array is installed so as to be separated from the light source, and includes a positive terminal and a negative terminal. The photodiode array generates a voltage difference between the positive terminal and the negative terminal when detecting the light signal. The positive terminal is connected to the ground terminal, and the depression type wide-band gap semiconductor switch includes: a gate electrode connected to the negative terminal; a drain electrode connected to the first output terminal; and a source electrode connected to the second output terminal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wide-bandgap photo relay, and particularly to a wide-bandgap photo relay provided with a depletion-type wide-bandgap semiconductor switch.

Background Art

[0002] In recent years, photo relays have been widely used in consumer electronic devices, automation and control systems, communication systems, electric vehicles, and the like.

[0003] A photo relay drives a light emitting diode (LED) at a low voltage to generate an optical signal, and controls the switching of a semiconductor switch on the high voltage load side. However, the off-state voltage and switching speed of the semiconductor switch of a conventional photo relay are limited by material characteristics, and it has been difficult to achieve significant improvement.

[0004] In view of the above circumstances, it has become an urgent issue for the industry to improve the reliability and durability of photo relays and meet the needs of various applications by increasing the off-state voltage of semiconductor switches and shortening the switching time.

Summary of the Invention

[0005] An object of the present invention is to provide a wide-bandgap photo relay with improved off-state voltage and switching speed by means of a depletion-type wide-bandgap semiconductor switch. The wide-bandgap photo relay of the present invention has characteristics such as high breakdown voltage, high-speed switching, high reliability, and high durability compared with conventional photo relays, and can meet the needs of various applications.

[0006] To achieve the above object, the present invention provides a wide bandgap photo relay. The wide bandgap photo relay includes a first input terminal, a second input terminal, a first output terminal, a second output terminal, a ground terminal, a light source that generates an optical signal and has a first end connected to the first input terminal and a second end connected to the second input terminal, a photodiode array that is installed separately from the light source, has a positive terminal and a negative terminal, generates a voltage difference between the positive terminal and the negative terminal when detecting the optical signal, and has the positive terminal connected to the ground terminal, and a depletion-mode wide bandgap semiconductor switch having a gate electrode connected to the negative terminal, a drain electrode connected to the first output terminal, and a source electrode connected to the second output terminal.

[0007] In an embodiment of the present invention, the light source is a gallium arsenide (GaAs) light emitting diode (LED).

[0008] In an embodiment of the present invention, the photodiode array includes a plurality of silicon photodiodes connected in series in an array.

[0009] In an embodiment of the present invention, the wide bandgap photo relay further includes a control circuit connected between the photodiode array and the depletion-mode wide bandgap semiconductor switch.

[0010] In an embodiment of the present invention, the depletion-mode wide bandgap semiconductor switch is a depletion-mode gallium nitride (GaN) high electron mobility transistor (HEMT) or a silicon carbide junction field-effect transistor (JFET).

[0011] In an embodiment of the present invention, the light source and the photodiode array are arranged laterally with respect to each other.

[0012] In an embodiment of the present invention, the light source and the photodiode array are arranged vertically with respect to each other.

[0013] In an embodiment of the present invention, the wide bandgap photo relay further includes a diode, an anode of the diode is connected to the source electrode, and a cathode of the diode is connected to the drain electrode.

[0014] The present invention provides a wide bandgap photo relay. The wide bandgap photo relay includes a first input terminal, a second input terminal, a first output terminal, a second output terminal, a ground terminal, a light source that generates an optical signal and has a first end connected to the first input terminal and a second end connected to the second input terminal, a photodiode array that is installed separately from the light source, has a positive terminal and a negative terminal, generates a voltage difference between the positive terminal and the negative terminal when sensing the optical signal, and the positive terminal is connected to the ground terminal, and a depletion-type wide bandgap semiconductor switch pair. The depletion-type wide bandgap semiconductor switch pair includes a first depletion-type wide bandgap semiconductor switch and a second depletion-type wide bandgap semiconductor switch. The first depletion-type wide bandgap semiconductor switch has a first source electrode, a first drain electrode, and a first gate electrode. The first gate electrode is connected to the negative terminal. The first drain electrode is connected to the first output terminal. The second depletion-type wide bandgap semiconductor switch has a second source electrode, a second drain electrode, and a second gate electrode. The second gate electrode is connected to the negative terminal. The second source electrode is connected to the first source electrode. The second drain electrode is connected to the second output terminal.

[0015] In an embodiment of the present invention, the light source is a gallium arsenide (GaAs) light emitting diode (LED).

[0016] In an embodiment of the present invention, the photodiode array includes a plurality of silicon photodiodes connected in series in an array.

[0017] In an embodiment of the present invention, the wide bandgap photo relay further includes a control circuit connected between the photodiode array and the depletion-type wide bandgap semiconductor switch pair.

[0018] In an embodiment of the present invention, the first depletion-type wide bandgap semiconductor switch and the second depletion-type wide bandgap semiconductor switch are depletion-type gallium nitride (GaN) high electron mobility transistors (HEMTs) or silicon carbide (SiC) junction field-effect transistors (JFETs).

[0019] In an embodiment of the present invention, the light source and the photodiode array are arranged laterally with respect to each other.

[0020] In an embodiment of the present invention, the light source and the photodiode array are arranged longitudinally with respect to each other.

[0021] In an embodiment of the present invention, the wide bandgap photo relay further includes a first diode and a second diode. The anode of the first diode is connected to the first source electrode, the cathode of the first diode is connected to the first drain electrode, the anode of the second diode is connected to the second source electrode, and the cathode of the second diode is connected to the second drain electrode.

[0022] Those skilled in the art can understand other objects of the present invention, as well as the technical means and embodiments of the present invention, by referring to the drawings and the embodiments described below.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0024] Hereinafter, the content of the present invention will be described through embodiments. It should be noted that the embodiments of the present invention are examples of embodiments, and are not intended to be limited to the environments, applications, or specific modes as described in the embodiments. Therefore, the description of the embodiments is for explaining the present invention, but does not limit the present invention. In the embodiments and the drawings, components not directly related to the present invention are omitted and not shown. The dimensional relationships of the respective components in the drawings are for facilitating understanding and do not limit the actual dimensions.

[0025] FIG. 1 is a circuit diagram showing a wide bandgap photorelays 1 according to an embodiment of the present invention. The wide bandgap photorelays 1 includes a first input terminal IT1, a second input terminal IT2, a first output terminal OT1, a second output terminal OT2, a ground terminal GT, a light source 11, a photodiode array 13, and a depletion type wide bandgap semiconductor switch 15.

[0026] The light source 11 generates an optical signal and has a first end 111 and a second end 112. The first end 111 is connected to the first input terminal IT1. The second end 112 is connected to the second input terminal IT2. The light source 11 is a gallium arsenide (GaAs) light emitting diode (LED) that generates infrared light with a wavelength of 840 nm to 920 nm, but is not limited thereto. By inputting a voltage from the first input terminal IT1 and the second input terminal IT2, the light source 11 can generate an optical signal.

[0027] The photodiode array 13 is installed separately from the light source 11. The photodiode array 13 has a positive terminal 131 and a negative terminal 132. When the photodiode array 13 detects an optical signal from the light source 11, a voltage difference is generated between the positive terminal 131 and the negative terminal 132. The positive terminal 131 of the photodiode array 13 is connected to the ground terminal GT. The photodiode array 13 includes a plurality of silicon photodiodes. The plurality of silicon photodiodes are connected in series in an array, but are not limited thereto. The voltage difference between the positive terminal 131 and the negative terminal 132 of the photodiode array 13 is, for example, 10 V to 25 V. The voltage difference depends on the number of silicon photodiodes connected in series.

[0028] The depletion-type wide-bandgap semiconductor switch 15 has a source electrode, a drain electrode, and a gate electrode. The gate electrode is connected to the negative terminal 132 of the photodiode array 13. The drain electrode is connected to the first output terminal OT1. The source electrode is connected to the second output terminal OT2. When the photodiode array 13 detects an optical signal and a voltage difference occurs between the positive terminal 131 and the negative terminal 132, the voltage of the gate electrode of the depletion-type wide-bandgap semiconductor switch 15 becomes a negative voltage smaller than the threshold voltage (which is a negative voltage) of the depletion-type wide-bandgap semiconductor switch 15. As a result, the depletion-type wide-bandgap semiconductor switch 15 is in the off state (i.e., non-conductive). Conversely, when no optical signal is detected by the photodiode array 13, the voltage of the gate electrode of the depletion-type wide-bandgap semiconductor switch 15 becomes 0. As a result, the depletion-type wide-bandgap semiconductor switch 15 is in the on state (i.e., conductive).

[0029] The depletion-type wide-bandgap semiconductor switch 15 is a semiconductor switch having a high breakdown electric field strength and a high saturated electron drift rate. For example, the depletion-type wide-bandgap semiconductor switch 15 is a depletion-type gallium nitride (GaN) high electron mobility transistor (HEMT) or a silicon carbide (SiC) junction field-effect transistor (JFET). The depletion-type gallium nitride high electron mobility transistor has, for example, a breakdown electric field strength of 3.3 MV / cm and a saturated electron drift rate of 2.5×10 7 cm / s. The silicon carbide junction field-effect transistor has, for example, a breakdown electric field strength of 3.5 MV / cm and a saturated electron drift rate of 2.0×10 7 cm / s.

[0030] In this way, for the depletion-mode wide-bandgap semiconductor switch 15 of the present invention, a gate electrode is connected to the negative terminal 132 of the photodiode array 13. Depending on whether the photodiode array 13 detects an optical signal from the light source 11, a voltage difference is generated between the positive terminal 131 and the negative terminal 132. In this manner, the depletion-mode wide-bandgap semiconductor switch 15 can be quickly turned on and off. Specifically, while the response time of an enhancement-mode wide-bandgap semiconductor switch is about 5 ns to 50 ns, the response time of the depletion-mode wide-bandgap semiconductor switch 15 is as short as about 1 ns to 20 ns, making it suitable for applications that require high-speed switching.

[0031] In practice, the light source 11 and the photodiode array 13 are arranged horizontally spaced apart on the package substrate (i.e., arranged horizontally (left and right)). Through optical path design (for example, installing a reflective coating containing silver, aluminum, polyethylene terephthalate (Mylar), or mica (Mica) on the top), the photodiode array 13 can receive the reflected light from the optical signal of the light source 11. Incidentally, in other embodiments, the light source 11 and the photodiode array 13 may be arranged vertically spaced apart on different package substrates (i.e., arranged vertically (up and down)). The photodiode array 13 receives the direct light of the optical signal from the light source 11. As described above, the positional relationship between the light source 11 and the photodiode array 13 can be changed by optical path design, and various positional relationships are included in the protection scope of the present invention.

[0032] Figure 2A is a circuit diagram of the wide-bandgap photorelays 2 according to an embodiment of the present invention. Different from the wide-bandgap photorelays 1, the wide-bandgap photorelays 2 further include a control circuit 21. The control circuit 21 is connected between the photodiode array 13 and the depletion-type wide-bandgap semiconductor switch 15. The control circuit 21 can further increase the switching speed. For example, as shown in Figure 2B, the control circuit 21 includes a transistor, two resistors, and a diode, but the present invention is not limited to this circuit configuration.

[0033] Figure 3 is a circuit diagram showing the wide-bandgap photorelays 3 according to an embodiment of the present invention. Different from the wide-bandgap photorelays 1, the wide-bandgap photorelays 3 further include a diode 31. As shown in Figure 3, the anode of the diode 31 is connected to the source electrode of the depletion-type wide-bandgap semiconductor switch 15. The cathode of the diode 31 is connected to the drain electrode of the depletion-type wide-bandgap semiconductor switch 15. In this way, the depletion-type wide-bandgap semiconductor switch 15 further has, for example, reverse bias protection and overvoltage protection so that the depletion-type wide-bandgap semiconductor switch 15 operates with the correct polarity.

[0034] Furthermore, in one embodiment, the wide-bandgap photorelays according to the present invention may include the control circuit 21 and the diode 31. That is, it is a combination of the wide-bandgap photorelays 2 and the wide-bandgap photorelays 3.

[0035] FIG. 4 is a circuit diagram showing a wide-bandgap photorelays 4 according to an embodiment of the present invention. The wide-bandgap photorelays 4 includes a first input terminal IT1, a second input terminal IT2, a first output terminal OT1, a second output terminal OT2, a ground terminal GT, a light source 41, a photodiode array 43, and a depletion-type wide-bandgap semiconductor switch pair (composed of a first depletion-type wide-bandgap semiconductor switch 45 and a second depletion-type wide-bandgap semiconductor switch 47).

[0036] Similar to the above, the light source 41 generates an optical signal and has a first end 411 and a second end 412. The first end 411 is connected to the first input terminal IT1. The second end 412 is connected to the second input terminal IT2. The light source 41 is a gallium arsenide (GaAs) light-emitting diode (LED), but is not limited thereto. By inputting a voltage from the first input terminal IT1 and the second input terminal IT2, the light source 41 can generate an optical signal.

[0037] The photodiode array 43 is installed separately from the light source 41. The photodiode array 43 has a positive terminal 431 and a negative terminal 432. The photodiode array 43 detects the optical signal from the light source 41. When detecting the optical signal, a voltage difference is generated between the positive terminal 431 and the negative terminal 432. The positive terminal 431 of the photodiode array 43 is connected to the ground terminal GT. The photodiode array 43 includes a plurality of silicon photodiodes. The plurality of silicon photodiodes are connected in series in an array, but are not limited thereto. Similarly, the voltage difference between the positive terminal 431 and the negative terminal 432 of the photodiode array 43 is, for example, 10V to 25V. The voltage difference depends on the number of silicon photodiodes connected in series.

[0038] The first depletion-mode wide-bandgap semiconductor switch 45 has a first source electrode, a first drain electrode, and a first gate electrode. The first gate electrode is connected to the negative terminal 432 of the photodiode array 43. The first drain electrode is connected to the first output terminal OT1. The second depletion-mode wide-bandgap semiconductor switch 47 has a second source electrode, a second drain electrode, and a second gate electrode. The second gate electrode is connected to the negative terminal of the photodiode array 43. The second source electrode is connected to the first source electrode. The second drain electrode is connected to the second output terminal OT2. When the photodiode array 43 detects an optical signal and a voltage difference occurs between the positive terminal 431 and the negative terminal 432, the voltages of the first gate electrode of the first depletion-mode wide-bandgap semiconductor switch 45 and the second gate electrode of the second depletion-mode wide-bandgap semiconductor switch 47 become negative voltages smaller than the threshold voltage (which is a negative voltage). As a result, the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 are in the off state (i.e., non-conductive). Conversely, when no optical signal is detected by the photodiode array 43, the voltages of the first gate electrode of the first depletion-mode wide-bandgap semiconductor switch 45 and the second gate electrode of the second depletion-mode wide-bandgap semiconductor switch 47 become zero. As a result, the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 are in the on state (i.e., conductive).

[0039] The first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 are semiconductor switches having a high breakdown electric field strength and a high saturation electron drift rate. For example, the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 are depletion-mode gallium nitride (GaN) high electron mobility transistors (HEMTs) or silicon carbide (SiC) junction field-effect transistors (JFETs). The depletion-mode gallium nitride high electron mobility transistor has, for example, a breakdown electric field strength of 3.3 MV / cm and a saturation electron drift rate of 2.5×10 7 cm / s. The silicon carbide junction field-effect transistor has, for example, a breakdown electric field strength of 3.5 MV / cm and a saturation electron drift rate of 2.0×10 7 cm / s.

[0040] Thus, the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 of the present invention connect a gate electrode to the negative terminal 432 of the photodiode array 43. A voltage difference is generated between the positive terminal 431 and the negative terminal 432 according to whether the photodiode array 43 detects an optical signal from the light source 41. In this way, the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 can be quickly turned on and off. As described above, the response time of the enhancement-mode wide-bandgap semiconductor switch is about 5 ns to 50 ns, whereas the response times of the first depletion-mode wide-bandgap semiconductor switch 45 and the second depletion-mode wide-bandgap semiconductor switch 47 are as short as about 1 ns to 20 ns, making them suitable for applications that require high-speed switching.

[0041] Similarly, in practice, the light source 41 and the photodiode array 43 are arranged horizontally spaced apart on the package substrate. Through the optical path design (for example, installing a reflective coating containing silver, aluminum, polyethylene terephthalate (Mylar), or mica (Mica) on the top), the photodiode array 43 can receive the reflected light from the optical signal of the light source 41. By the way, in other embodiments, the light source 41 and the photodiode array 43 may be arranged vertically spaced apart on different package substrates. The photodiode array 43 receives the direct light of the optical signal from the light source 41. As described above, the positional relationship between the light source 41 and the photodiode array 43 can be changed by the optical path design, and various positional relationships are included in the protection scope of the present invention.

[0042] FIG. 5 is a circuit diagram of the wide-bandgap photorelays 5 according to an embodiment of the present invention. Different from the wide-bandgap photorelays 4, the wide-bandgap photorelays 5 further include a control circuit 21 connected between the photodiode array 43 and the depletion-type wide-bandgap semiconductor switch pair. The control circuit 21 can further increase the switching speed. As described above, as shown in FIG. 2B, the control circuit 21 includes a transistor, two resistors, and a diode, but the present invention is not limited to this circuit configuration.

[0043] FIG. 6 is a circuit diagram showing a wide bandgap photo relay 6 according to an embodiment of the present invention. Different from the wide bandgap photo relay 4, the wide bandgap photo relay 6 further includes a first diode 61 and a second diode 63. As shown in FIG. 6, the anode and the cathode of the first diode 61 are connected to the first source electrode and the first drain electrode of the first depletion type wide bandgap semiconductor switch 45, respectively. The anode and the cathode of the second diode are connected to the second source electrode and the second drain electrode of the second depletion type wide bandgap semiconductor switch 47, respectively. In this way, the first depletion type wide bandgap semiconductor switch 45 and the second depletion type wide bandgap semiconductor switch 47 further have, for example, reverse bias protection and overvoltage protection so that the first depletion type wide bandgap semiconductor switch 45 and the second depletion type wide bandgap semiconductor switch 47 operate with the correct polarity.

[0044] The above wide bandgap photo relays 1 to 6 can be modularized respectively. This module can be used in consumer electronic devices, automation and control systems, communication systems, electric vehicles, etc., and provides a switching function by connecting to other circuits.

[0045] FIG. 7 is a timing chart showing the states of the respective components during the operation of a wide bandgap photo relay (for example, the wide bandgap photo relays 1 to 6 in the above embodiment) according to an embodiment of the present invention. V in is the voltage input from the first input terminal IT1 and the second input terminal IT2. The drive voltage of the light source (for example, the light source 11 or the light source 41) is usually from 3V to 5V. I LED is the drive current flowing through the light source and corresponds to V in . I LED is usually from 0.5 mA to 10 mA. Φ LED is the radiant flux of the optical signal of the light source and is usually in units of milliwatts (mW).

[0046] I PDA is the detection current generated when an optical signal is detected by a photodiode array (e.g., photodiode array 13 or photodiode array 43), and is usually 10 uA to 100 uA. V PDA is the detection voltage across both ends of the photodiode array due to the detection of the optical signal, and is usually 20 V to 30 V. V th is the threshold voltage of the depletion-type wide-bandgap semiconductor switch, and is a negative voltage. V G is the gate voltage of the depletion-type wide-bandgap semiconductor switch (e.g., depletion-type wide-bandgap semiconductor switch 15, first depletion-type wide-bandgap semiconductor switch 45, second depletion-type wide-bandgap semiconductor switch 47). In the present invention, since the positive terminal of the photodiode array is connected to the ground terminal GT, V G is equal to -V PDA and is usually -5 V to -25 V, and is smaller than V th . As shown in FIG. 7, I out is the output current between the first output terminal OT1 and the second output terminal OT2, and switches between 0 and I dd . I dd is the input current on the high-voltage load side, and is usually 1 A to 50 A.

[0047] As can be seen from FIG. 7, when a voltage is input from the first input terminal IT1 and the second input terminal IT2 (i.e., when the bias voltage of V in is turned on), the light source is driven (i.e., the light source lights up) and an optical signal is generated. At this time, since V G is -V PDA , the depletion-type wide-bandgap semiconductor switch is turned off. Thereafter, when no voltage is input from the first input terminal IT1 and the second input terminal IT2 (i.e., when the bias voltage of V in is turned off), the light source is not driven (i.e., the light source is turned off). At this time, since V G is 0 V, the depletion-type wide-bandgap semiconductor switch is turned on. Therefore, V inBy turning the light source on and off according to the on / off of the bias, the switch can be switched quickly.

[0048] As described above, the wide-bandgap photorelays according to the present invention can improve the off-state voltage and switching speed by a depletion-type wide-bandgap semiconductor switch. Therefore, the wide-bandgap photorelays of the present invention have characteristics such as high breakdown voltage, high-speed switching, high reliability, and high durability compared with conventional photorelays, and can meet the needs of various applications.

[0049] The above embodiments illustrate the embodiments of the present invention and explain the characteristic configurations of the present invention. The present invention is not limited to the above embodiments. Modifications or equivalent arrangements that can be easily made by those skilled in the art are also within the scope of the present invention. The scope of protection of the rights of the present invention shall be based on the scope of the claims.

Description of Reference Numerals

[0050] 1 Wide-bandgap photorelays 2 Wide-bandgap photorelays 3 Wide-bandgap photorelays 4 Wide-bandgap photorelays 5 Wide-bandgap photorelays 6 Wide-bandgap photorelays IT1 First input terminal IT2 Second input terminal OT1 First output terminal OT2 Second output terminal GT Ground terminal 11 Light source 41 Light source 13 Photodiode array 43 Photodiode array 15 Depletion-type wide-bandgap semiconductor switch 45 First depletion-type wide-bandgap semiconductor switch 47 Second Depression-Type Wide Bandgap Semiconductor Switch 111 First Terminal 411 First Terminal 112 Second Terminal 412 Second Terminal 131 Positive Terminal 431 Positive Terminal 132 Negative Terminal 432 Negative Terminal 21 Control Circuit 31 Diode 61 First Diode 63 Second Diode

Claims

1. A wide band gap photorelay, A first input terminal; A second input terminal; A first output terminal; A second output terminal; A ground terminal; a light source generating an optical signal and having a first end connected to the first input terminal and a second end connected to the second input terminal; a photodiode array disposed separately from the light source, having a positive terminal and a negative terminal, generating a voltage difference between the positive terminal and the negative terminal when detecting the optical signal, and having the positive terminal connected to the ground terminal; a depletion-type wide bandgap semiconductor switch having a gate electrode connected to the negative terminal, a drain electrode connected to the first output terminal, and a source electrode connected to the second output terminal.

2. 2. The wide bandgap photorelay according to claim 1, wherein the light source is a gallium arsenide (GaAs) light emitting diode (LED).

3. 2. The wide bandgap photorelay according to claim 1, wherein the photodiode array includes a plurality of silicon photodiodes connected in series in an array.

4. 2. The wide bandgap photorelay according to claim 1, further comprising a control circuit connected between the photodiode array and the depletion-type wide bandgap semiconductor switch.

5. 2. The wide bandgap photorelay of claim 1, wherein the depletion-type wide bandgap semiconductor switch is a depletion-type gallium nitride (GaN) high electron mobility transistor (HEMT) or a silicon carbide (SiC) junction field-effect transistor (JFET).

6. 2. The wide bandgap photorelay of claim 1, wherein the light source and the photodiode array are disposed laterally relative to one another.

7. 2. The wide bandgap photorelay of claim 1, wherein the light source and the photodiode array are arranged vertically relative to each other.

8. Further comprising a diode; 2. The wide bandgap photorelay according to claim 1, wherein the anode of the diode is connected to the source electrode, and the cathode of the diode is connected to the drain electrode.

9. A wide band gap photorelay, A first input terminal; A second input terminal; A first output terminal; A second output terminal; A ground terminal; a light source generating an optical signal and having a first end connected to the first input terminal and a second end connected to the second input terminal; a photodiode array disposed separately from the light source, having a positive terminal and a negative terminal, generating a voltage difference between the positive terminal and the negative terminal when detecting the optical signal, and having the positive terminal connected to the ground terminal; a depletion type wide bandgap semiconductor switch pair including a first depletion type wide bandgap semiconductor switch and a second depletion type wide bandgap semiconductor switch; the first depletion-type wide bandgap semiconductor switch has a first gate electrode connected to the negative terminal, a first drain electrode connected to the first output terminal, and a first source electrode; the second depletion-type wide bandgap semiconductor switch has a second gate electrode connected to the negative terminal, a second source electrode connected to the first source electrode, and a second drain electrode connected to the second output terminal.

10. 10. The wide bandgap photorelay according to claim 9, wherein the light source is a gallium arsenide (GaAs) light emitting diode (LED).

11. 10. The wide bandgap photorelay of claim 9, wherein the photodiode array includes a plurality of silicon photodiodes connected in series in an array.

12. 10. The wide bandgap photorelay according to claim 9, further comprising a control circuit connected between the photodiode array and the pair of depletion-type wide bandgap semiconductor switches.

13. 10. The wide bandgap photorelay of claim 9, wherein the first depletion type wide bandgap semiconductor switch and the second depletion type wide bandgap semiconductor switch are depletion type gallium nitride (GaN) high electron mobility transistors (HEMTs) or silicon carbide (SiC) junction field-effect transistors (JFETs).

14. 10. The wide bandgap photorelay of claim 9, wherein the light source and the photodiode array are disposed laterally relative to one another.

15. 10. The wide bandgap photorelay of claim 9, wherein the light source and the photodiode array are arranged vertically relative to each other.

16. Further comprising a first diode and a second diode, 10. The wide bandgap photorelay of claim 9, wherein an anode of the first diode is connected to the first source electrode, a cathode of the first diode is connected to the first drain electrode, an anode of the second diode is connected to the second source electrode, and a cathode of the second diode is connected to the second drain electrode.

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