CN-122026881-A - Optical relay and electronic device

Abstract

The embodiment of the application discloses an optical relay, which is characterized in that a first transistor, a second transistor and a first triode are arranged, when a light emitting diode does not emit light, the first transistor, the second transistor and the first triode are all conducted, and compared with the fact that only the first transistor is used for extracting current, the capability of extracting current is greatly improved, so that the time from conduction to complete disconnection of a power output switch module is greatly shortened.

Inventors

• SHAO LILI
• HE HUISEN

Assignees

• 南京矽力微电子技术有限公司

Dates

Publication Date

20260512

Application Date

20251229

Claims (18)

1. 1. An optical relay, the optical relay comprising: The light emitting module receives the electric signal to control the light emitting diode; the power output switch module comprises a switch tube, and the state of the switch tube is controlled by a control signal; The light receiving conversion module comprises a light receiving diode string, a first transistor and a second transistor, wherein the light receiving diode string is used for receiving light signals of the light emitting diode, a first power electrode of the first transistor is connected with a first power electrode of the first transistor and is connected with an anode of the light receiving diode string and a control electrode of the switch tube, the control electrode of the first transistor is connected with the control electrode of the second transistor, and when the light emitting diode does not emit light, the first transistor and the second transistor are both conducted.
2. 2. The optical relay of claim 1, wherein: The light receiving conversion module further comprises a clamping circuit, and the voltage difference between the second power poles and the control poles of the first transistor and the second transistor is controlled by the clamping circuit; the clamping circuit comprises a first resistor and a clamping diode string which are connected in parallel.
3. 3. The relay of claim 1, wherein: The first transistor and the second transistor are depletion transistors.
4. 4. The optical relay of claim 1, wherein: the diodes in the clamping diode string are light emitting diodes.
5. 5. The optical relay of claim 2, wherein: The anode of the clamping diode string is connected with the cathode of the light receiving diode string, and the cathode is connected with the control electrode of the first transistor and the control electrode of the second transistor.
6. 6. The optical relay of claim 2, wherein: the optical relay further comprises a protection module, wherein the protection module comprises a first triode and a second triode which are connected back to back, the base electrode of the first triode is connected with the collector electrode of the second triode and is connected with the cathode of the light receiving diode string, and the emitter electrode of the first triode is connected with the base electrode of the second triode and is connected with the second power electrode of the first transistor.
7. 7. The optical relay of claim 6, wherein: when the light emitting diode does not emit light, the first triode and the second triode are disconnected, and the second triode is gradually turned on and the first triode is kept off along with the enhancement of illumination.
8. 8. The optical relay of claim 6, wherein: When the power output switch module needs to be turned off, the first transistor and the second transistor are gradually turned on, the first triode is turned on, and the second triode is turned off.
9. 9. The optical relay of claim 6, wherein: the light receiving conversion module further comprises a second resistor, one end of the second resistor is connected with the base electrode of the first triode, and the other end of the second resistor is connected with the second power stage of the second transistor.
10. 10. The optical relay of claim 6, wherein: When the first transistor and the second transistor are both turned off, the second triode is turned on, and-R1×IPD2< -VF_Pd2 is M, the voltage difference between the gates and the sources of the first transistor and the second transistor is clamped, wherein IPD2 is the current generated by the clamping diode string PD2, R1 is the resistance value of the first resistor, VF_Pd2 is the forward voltage drop when a single diode in the clamping diode string is turned on, and M is the number of diodes in the clamping diode string.
11. 11. The optical relay of claim 10, wherein: the voltage difference between the gates and sources of the first transistor and the second transistor is clamped at-VF_PD2-M2_VBE, wherein Q2_VBE is the voltage difference between the base and emitter of the second transistor.
12. 12. The optical relay of claim 9, wherein: And the on threshold current of the light emitting diode of the optical relay is adjusted by adjusting the resistance value of the first resistor and/or the second resistor.
13. 13. The optical relay of claim 12, wherein: When the light emitting diode starts to emit light, the current IPD2 generated by the clamping diode string meets the requirement that R1 is equal to or greater than IPD2-Q2_VBE and is equal to or greater than Vth1, wherein Vth1 is the conduction threshold of the first transistor, R1 is the resistance value of the first resistor, and Q2_VBE is the voltage difference between the base electrode and the emitter electrode of the second triode.
14. 14. The optical relay of claim 12, wherein: When the light emitting diode starts to emit light, the current flowing through the second resistor is equal to the current IMDN2 flowing through the second transistor, and the current IPD2 generated by the clamping diode string is equal to or greater than-R1.IPD 2-R2.IMDN 2, wherein Vth2 is the conduction threshold of the second transistor MDN2, R1 is the resistance of the first resistor, and R2 is the resistance of the second resistor.
15. 15. The optical relay of claim 6, wherein: when surge current appears at the moment of switching tube conduction or ESD moment in the power output switching module, the first triode is conducted and used for absorbing the surge current.
16. 16. The optical relay of claim 1, wherein: the light emitting module, the power output switch module and the light receiving conversion module are integrated in one chip.
17. 17. The optical relay of claim 1, wherein: The power output switch module comprises a first switch tube and a second switch tube, wherein the control electrode of the first switch tube is connected with the control electrode of the second switch tube, and the second power electrode of the first switch tube is connected with the second power electrode of the second switch tube.
18. 18. An electronic device, characterized in that: An optical relay comprising any one of claims 1 to 17.

Description

Optical relay and electronic device Technical Field The application relates to the field of electronic circuits, in particular to an optical relay and electronic equipment. Background The optical relay is a technology for realizing electrical isolation through optical signals and is widely applied to the fields of power electronics, communication, industrial control and the like. In the prior art, when the power output switch module needs to be turned off, only one transistor is turned on to draw current, and the current drawing capability is limited. Disclosure of Invention The embodiment of the application provides an optical relay which comprises an optical emission module, a power output switch module, an optical receiving conversion module and a light receiving conversion module, wherein the optical emission module receives an electric signal to control a light emitting diode, the power output switch module comprises a switch tube, the state of the switch tube is controlled through a control signal, the optical receiving conversion module comprises a light receiving diode string, a first transistor and a second transistor, the light receiving diode string is used for receiving an optical signal of the light emitting diode, a first power electrode of the first transistor is connected with a first power electrode of the first transistor and is connected with an anode of the light receiving diode string and is connected with a control electrode of the switch tube, a control electrode of the first transistor is connected with a control electrode of the second transistor, and when the light emitting diode does not emit light, the first transistor and the second transistor are both conducted. Preferably, the light receiving conversion module further comprises a clamping circuit, wherein the voltage difference between the second power poles and the control poles of the first transistor and the second transistor is controlled by the clamping circuit, and the clamping circuit comprises a first resistor and a clamping diode string which are connected in parallel. On the other hand, the embodiment of the application also provides electronic equipment, which comprises the optical relay. The embodiment of the application provides an optical relay, wherein an optical receiving conversion module comprises a clamping circuit, when the light intensity of an LED is large, the voltage difference between a second power pole and a control pole of a first transistor and a second transistor is controlled by the clamping circuit, the voltage difference is used for protecting the first transistor and the second transistor, the voltage application range of the optical relay is enlarged, in addition, by adding a protection module, when a switch in the power output switch module is conducted instantly or surge current appears instantly in ESD, the protection module is used for absorbing large current, the anti-surge performance is improved, when the power output switch module is matched with an ultrahigh voltage power transistor for use, the optical relay can be applied to a high voltage scene, and when the power output switch module needs to be turned off, the first transistor, the second transistor and the first triode are all turned on, compared with the fact that the first transistor is only used for extracting current, the current extracting capacity is greatly improved, and therefore the time from the conduction to the complete disconnection of the power output switch module is greatly shortened in the process from light emitting to the ESD. Drawings The above and other objects, features and advantages of the present application will become more apparent from the following description of embodiments of the present application with reference to the accompanying drawings, in which: Fig. 1 is a block diagram of an optical relay according to an embodiment of the present application; Fig. 2 is a circuit diagram of an optical relay according to an embodiment of the present application. Detailed Description The present application is described below based on examples, but the present application is not limited to only these examples. In the following detailed description of the present application, certain specific details are set forth in detail. The present application will be fully understood by those skilled in the art without the details described herein. Well-known methods, procedures, flows, components and circuits have not been described in detail so as not to obscure the nature of the application. It will be appreciated by those of ordinary skill in the art that the drawings provided herein are for illustrative purposes and that the drawings are not necessarily drawn to scale. It should be understood that in the following description, "circuit" refers to an electrically conductive loop formed by at least one element or sub-circuit through electrical or electromagnetic connection. When an element or circuit is referred to