CN-122026879-A - Optical relay and electronic device

CN122026879ACN 122026879 ACN122026879 ACN 122026879ACN-122026879-A

Abstract

The embodiment of the application discloses an optical relay, which comprises a protection module, wherein the protection module is connected with a control end of a switching tube in a power output switching module and is used for absorbing surge current, so that the reliability of the optical relay is improved.

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 (15)

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 through a control signal so as to control whether power is output or not; The light receiving conversion module comprises a light receiving diode string and a first transistor, wherein the light receiving diode string is used for receiving the light signals of the light emitting diode; and the protection module is connected with the control end of the switching tube and used for absorbing surge current.
2. The optical relay of claim 1, wherein: The protection module comprises a first triode and a second triode which are connected back to back, wherein 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 emitting 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.
3. The optical relay of claim 2, wherein: The protection 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 base electrode of the second triode.
4. The optical relay of claim 1, wherein: The light receiving conversion module further comprises a clamping circuit, wherein the voltage difference between the second power pole and the control pole of the first 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.
5. The optical relay of claim 4, wherein: the diodes in the clamping diode string are light emitting diodes.
6. The optical relay of claim 4, 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.
7. The optical relay of claim 4, wherein: And in the process from the fact that the light emitting diode does not exist to the fact that the power output switch module is conducted, the first triode and the second triode are disconnected.
8. The optical relay of claim 2, wherein: when surge current occurs, the first triode is conducted and used for absorbing the surge current.
9. The optical relay of claim 8, wherein: When an in-rush current occurs, the voltage difference between the gate and the source of the switching tube in the power output switching module is clamped to VF_PD1+N+Q1_VBE, wherein VF_PD1 is the forward voltage drop when a single diode in the light receiving diode string is conducted, N is the number of diodes in the light receiving diode string, and Q1_VBE is the voltage difference between the base and the emitter of the first transistor.
10. The optical relay of claim 8, wherein: When surge current occurs, when-R1×IPD2< -VF PD2×M, the voltage difference between the grid electrode and the source electrode of the first transistor is clamped at-VF_Pd2×M-Q2_VBE, wherein Q2_VBE is the voltage difference between the base electrode and the emitter electrode of the second transistor, VF_Pd2 is the forward voltage drop when a single diode in the clamping diode string is conducted, M is the number of the diodes in the clamping diode string, R1 is the resistance value of the first resistor, and IPD2 is the current generated by the clamping diode string.
11. The optical relay of claim 4, wherein: and adjusting the conduction threshold current of the light emitting diode by adjusting the resistance values of the first resistor and the second resistor.
12. The optical relay of claim 11, wherein: When the light emitting diode starts to emit light, the current IPD1 generated by the light receiving diode string and the current IPD2 generated by the clamping diode string meet the conditions that-R1 is equal to or larger than IPD2-R2, wherein Vth1 is the conduction threshold of the first transistor, R1 is the resistance of the first resistor, and R2 is the resistance of the second resistor.
13. 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 package.
14. 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.
15. An electronic device, characterized in that: An optical relay comprising any one of claims 1 to 14.

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. When a switch in the power output switch module is turned on instantaneously or surge current appears instantaneously in ESD, current in the optical relay circuit is increased, so that the element of the optical relay is affected, and even damage is caused. 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 protection 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 to control whether power is output or not, the optical receiving conversion module comprises a light receiving diode string and a first 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 an anode of the light receiving diode string and is connected with a control electrode of the switch tube, and the protection module is connected with a control end of the switch tube and is used for absorbing surge current. Optionally, the protection module comprises a first triode and a second triode which are connected back to back, wherein 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. The embodiment of the application also provides electronic equipment comprising the optical relay. According to the optical relay provided by the embodiment of the application, the protection module is added, so that when the switch in the power output switch module is turned on instantly or surge current appears instantly by ESD, the protection module is used for absorbing large current and improving the anti-surge performance, and when the power output switch module is matched with an ultra-high voltage power tube for use, the optical relay can be applied to a high-voltage scene, the voltage application range of the optical relay is enlarged, and the reliability of the optical relay is improved. Meanwhile, through the arrangement of the protection module, when surge current occurs, the voltage difference between the grid electrode and the source electrode of the switching tube in the first transistor and the power output switching module is clamped, so that damage caused by instant overvoltage is prevented, the reliability is higher, and the surge prevention performance is better. 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 as being "connected to" another element or being "connected between" two nodes, it can be directly connected or connected to the other element or intervening elements may be present and the connection between the elements may be physical, logical, or a combination thereof. In contrast, when an element is referred to as being "directly connected to" another element, it means that there are