An isolated communication system with high voltage switch function

Abstract

The present invention relates to the technical field of isolated communication, and specifically discloses an isolated communication system with a high-voltage switch function, comprising a high-voltage control switch, a high-voltage power conversion module, a control module, two isolation control devices, a low-voltage power conversion module, a digital isolator and a communication chip, wherein the high-voltage control switch is connected to the high-voltage power supply, the high-voltage control switch is respectively connected to the control module and the digital isolator through the high-voltage power conversion module, the control module is respectively connected to the second isolation control device and the digital isolator, the low-voltage power supply is respectively connected to the low-voltage power conversion module and the communication chip, an external communication signal is connected to the low-voltage power conversion module through the communication chip, the low-voltage power conversion module is respectively connected to the digital isolator and the first isolation control device, the communication chip is connected to the digital isolator, and the first isolation control device and the second isolation control device are connected to the high-voltage control switch through an OR gate; the present invention can realize the power-on and power-off control of the high-voltage power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of isolated communication, and in particular to an isolated communication system with a high-voltage switch function. Background Art

[0002] like Figure 1 As shown, currently isolated communication is often achieved by using isolated transceivers or isolated optocouplers, but isolated transceivers are only applicable to certain communication methods. Some communication methods, such as LIN and CAN communication that require a specified node to wake up, rarely have suitable integrated solutions. Alternatively, discrete solutions can be used to achieve the above functions, but the method of waking up the secondary side on the primary side requires a more complex isolated power supply to control the high-voltage loop power supply. However, there are the following problems:

[0003] ① High complexity - an additional switching power supply is required to convert the power supply on the low-voltage side into the power supply on the high-voltage side to power the high-voltage side system;

[0004] ② High cost: Additional switching power supply chips and transformers have a high impact on system cost;

[0005] ③ The low-voltage power supply has a large load - the low-voltage power supply, as the power supply for the high-voltage side, will generate a certain load on the low-voltage side power supply;

[0006] ④It is impossible to directly control the on and off of the high-voltage side power supply. Summary of the invention

[0007] In view of the defects and shortcomings in the prior art, the present invention provides an isolated communication system with a high-voltage switching function to solve the problems of high complexity, high cost, large low-voltage power supply load, and inability to directly control the on and off of the high-voltage side power supply in the existing isolated communication circuits.

[0008] As a first aspect of the present invention, an isolated communication system with a high-voltage switch function is provided, the isolated communication system with a high-voltage switch function comprising a high-voltage control switch, a high-voltage power conversion module, a control module, a first isolation control device, a second isolation control device, a low-voltage power conversion module, a digital isolator and a communication chip, the high-voltage control switch is connected to the high-voltage power supply, the high-voltage control switch is also connected to the control module and the digital isolator respectively through the high-voltage power conversion module, the control module is respectively connected to the second isolation control device and the digital isolator, the low-voltage power supply is respectively connected to the low-voltage power conversion module and the communication chip, an external communication signal is connected to the low-voltage power conversion module through the communication chip, the low-voltage power conversion module is respectively connected to the digital isolator and the first isolation control device, the communication chip is connected to the digital isolator, the first isolation control device and the second isolation control device are connected to the high-voltage control switch through an OR gate; wherein,

[0009] The low-voltage power supply supplies power to the communication chip and the low-voltage power conversion module, and the low-voltage power conversion module provides a stable low-voltage side digital power supply for the digital isolator;

[0010] The external communication signal communicates with the control module through the communication chip and the digital isolator in turn; the communication chip can enter a dormant state, and when the external communication signal wakes up the communication chip, the communication chip controls the low-voltage power conversion module, and then controls the first isolation control device to issue an opening instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to turn on, thereby achieving the communication wake-up function of the isolated communication system;

[0011] After the high-voltage control switch is turned on, the control module controls the second isolation control device to send a power-on hold instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to remain turned on;

[0012] When the communication chip receives an external sleep command, the low-voltage power conversion module is powered off, and the first isolation control device is controlled to issue a first shutdown command to the high-voltage control switch. At this time, the control module needs to store data for a period of time to enter the shutdown sequence, and then controls the second isolation control device to issue a second shutdown command to the high-voltage control switch, thereby controlling the high-voltage control switch to shut down.

[0013] Furthermore, after the first isolation control device sends an on command to the high-voltage control switch, the high-voltage control switch is turned on; after the second isolation control device sends a power-on hold command to the high-voltage control switch, the high-voltage control switch remains on; after both the first isolation control device and the second isolation control device send an off command to the high-voltage control switch, the high-voltage control switch is turned off.

[0014] Furthermore, when the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module generates a VDD voltage to supply power to the high-voltage side of the digital isolator and the control module respectively.

[0015] Furthermore, when the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module can supply power to the high-voltage load.

[0016] Furthermore, the high-voltage control switch is a relay RE1, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is a transistor Q1 and a first pin and a second pin of the relay RE1, the second isolation control device is an isolation optocoupler IC2, and the communication chip IC1 is integrated with the low-voltage power conversion module; the seventh pin of the relay RE1 is connected to the DC-DC converter, and the DC-DC converter is respectively connected to the first pin of the isolation optocoupler IC2 and the digital isolator IC3 through the MCU, the first pin of the relay RE1 is respectively connected to the collector of the transistor Q1 and the fourth pin of the isolation optocoupler IC2, the second pin of the relay RE1 is connected to the seventh pin of the communication chip IC1, and the base of the transistor Q1 is connected to the eighth pin of the communication chip IC1.

[0017] Furthermore, the high-voltage control switch includes a first switch tube Q3 and a second switch tube Q4, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is an isolation optocoupler IC4, the second isolation control device is a transistor Q5, and the low-voltage power conversion module is integrated in the communication chip IC5; the second pin of the first switch tube Q3 is connected to the high-voltage power supply, the second pin of the second switch tube Q4 is connected to the DC-DC converter, the DC-DC converter is respectively connected to the base of the transistor Q5 and the digital isolator IC6 through the MCU, the first pin of the first switch tube Q3 and the first pin of the second switch tube Q4 are respectively connected to the third pin of the isolation optocoupler IC4 and the collector of the transistor Q5 through a resistor R1, and the second pin of the isolation optocoupler IC4 and the eighth pin of the communication chip IC5 are both connected to the VCC voltage.

[0018] The isolated communication system with high-voltage switch function provided by the present invention has the following advantages:

[0019] (1) The high-voltage side is completely in the off state before the system wakes up, with extremely low high-voltage side leakage current;

[0020] (2) Directly control the high voltage control switch through the low voltage side, which is highly safe;

[0021] (3) Using an isolation device to realize the switch on the low-voltage side to control the high-voltage side is more cost-effective;

[0022] (4) Communication transceivers can use low-voltage devices, without the need for isolation, which is more flexible;

[0023] (5) Able to use communication chips and control modules to coordinate the up and down control of high-voltage power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0025] Figure 1 It is a structural diagram of an existing isolated communication circuit.

[0026] Figure 2 This is a structural block diagram of the isolated communication system with high-voltage switch function provided by the present invention.

[0027] Figure 3 A first specific circuit structure diagram of the isolated communication system with high-voltage switch function provided by the present invention.

[0028] Figure 4 A second specific circuit structure diagram of the isolated communication system with high-voltage switch function provided by the present invention. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] In this embodiment, an isolated communication system with a high-voltage switch function is provided. Figure 2 This is a structural block diagram of an isolated communication system with a high voltage switch function provided by the present invention. Figure 2 As shown, the isolated communication system with high-voltage switch function includes a high-voltage control switch, a high-voltage power conversion module, a control module, a first isolation control device, a second isolation control device, a low-voltage power conversion module, a digital isolator and a communication chip. The high-voltage control switch is connected to the high-voltage power supply. The high-voltage control switch is also connected to the control module and the digital isolator respectively through the high-voltage power conversion module. The control module is connected to the second isolation control device and the digital isolator respectively. The low-voltage power supply is connected to the low-voltage power conversion module and the communication chip respectively. The external communication signal is connected to the low-voltage power conversion module through the communication chip. The low-voltage power conversion module is connected to the digital isolator and the first isolation control device respectively. The communication chip is connected to the digital isolator. The first isolation control device and the second isolation control device are connected to the high-voltage control switch through an OR gate; wherein,

[0033] The low-voltage power supply supplies power to the communication chip and the low-voltage power conversion module, and the low-voltage power conversion module provides a stable low-voltage side digital power supply for the digital isolator;

[0034] The external communication signal communicates with the control module through the communication chip and the digital isolator in turn; the communication chip can enter a dormant state, and when the external communication signal wakes up the communication chip, the communication chip controls the low-voltage power conversion module, and then controls the first isolation control device to issue an opening instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to turn on, thereby achieving the communication wake-up function of the isolated communication system;

[0035] After the high-voltage control switch is turned on, the control module controls the second isolation control device to send a power-on hold instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to remain turned on;

[0036] When the communication chip receives an external sleep command, the low-voltage power conversion module is powered off, and the first isolation control device is controlled to issue a first shutdown command to the high-voltage control switch. At this time, the control module needs to store data for a period of time to enter the shutdown sequence, and then controls the second isolation control device to issue a second shutdown command to the high-voltage control switch, thereby controlling the high-voltage control switch to shut down.

[0037] Specifically, the first isolation control device and the second isolation control device control the opening of the high-voltage control switch as an OR gate, that is, after the first isolation control device sends an opening instruction to the high-voltage control switch, the high-voltage control switch is turned on; after the second isolation control device sends a power-on hold instruction to the high-voltage control switch, the high-voltage control switch remains turned on; after the first isolation control device and the second isolation control device both send a shutdown instruction to the high-voltage control switch, the high-voltage control switch is turned off.

[0038] Specifically, when the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module generates a VDD voltage to supply power to the high-voltage side of the digital isolator and the control module respectively.

[0039] Specifically, when the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module can supply power to the high-voltage load.

[0040] Preferably, if Figure 3 As shown, the high-voltage control switch is a relay RE1, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is a transistor Q1 and a first pin and a second pin of the relay RE1, the second isolation control device is an isolation optocoupler IC2, and the communication chip IC1 is integrated with the low-voltage power conversion module; the seventh pin of the relay RE1 is connected to the DC-DC converter, and the DC-DC converter is respectively connected to the first pin of the isolation optocoupler IC2 and the digital isolator IC3 through the MCU, the first pin of the relay RE1 is respectively connected to the collector of the transistor Q1 and the fourth pin of the isolation optocoupler IC2, the second pin of the relay RE1 is connected to the seventh pin of the communication chip IC1, and the base of the transistor Q1 is connected to the eighth pin of the communication chip IC1.

[0041] It should be noted that the isolation optocoupler IC2 can be replaced by other isolation switch tubes, and the transistor Q1 can be replaced by a MOSFET tube.

[0042] Preferably, if Figure 4As shown, the high-voltage control switch includes a first switch tube Q3 and a second switch tube Q4, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is an isolation optocoupler IC4, the second isolation control device is a transistor Q5, and the low-voltage power conversion module is integrated in the communication chip IC5; the second pin of the first switch tube Q3 is connected to the high-voltage power supply, the second pin of the second switch tube Q4 is connected to the DC-DC converter, the DC-DC converter is respectively connected to the base of the transistor Q5 and the digital isolator IC6 through the MCU, the first pin of the first switch tube Q3 and the first pin of the second switch tube Q4 are respectively connected to the third pin of the isolation optocoupler IC4 and the collector of the transistor Q5 through a resistor R1, and the second pin of the isolation optocoupler IC4 and the eighth pin of the communication chip IC5 are both connected to the VCC voltage.

[0043] It should be noted that the first switch tube Q3 and the second switch tube Q4 can be MOSFET tubes or other switch devices, the isolation optocoupler IC4 can be replaced by other isolation switch tubes, and the transistor Q5 can be replaced by a MOSFET tube.

[0044] It should be noted that when selecting different high-voltage control switches, the second isolation control device can determine whether to use the second isolation control device according to the characteristics of the high-voltage control switch. Figure 3 The example requires the use of a second isolation control device, Figure 4 The example does not require the use of a second isolation control device.

[0045] In an embodiment of the present invention, the control signal generated by the communication chip can control the low-voltage power conversion module on the low-voltage side and the high-voltage control switch on the high-voltage side, thereby achieving extremely low leakage current on both the high and low voltage sides.

[0046] In an embodiment of the present invention, the control and communication signals between high and low voltages can be isolated through a first isolation control device, a second isolation control device and a digital isolator; the communication function of the system is implemented by a communication chip, and its communication with the high-voltage side control module is isolated through a digital isolator.

[0047] In an embodiment of the present invention, the opening of the high-voltage control switch is controlled by a first isolation control device, and the power-on and opening of the high-voltage control switch is controlled by a second isolation control device. When both signals are shutdown signals, the high-voltage control switch is turned off.

[0048] The working principle of the isolated communication system with high-voltage switch function provided by the embodiment of the present invention is as described above and will not be repeated here.

[0049] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An isolated communication system with high voltage switch function, characterized in that: The isolated communication system with high-voltage switch function includes a high-voltage control switch, a high-voltage power conversion module, a control module, a first isolation control device, a second isolation control device, a low-voltage power conversion module, a digital isolator and a communication chip. The high-voltage control switch is connected to the high-voltage power supply. The high-voltage control switch is also connected to the control module and the digital isolator respectively through the high-voltage power conversion module. The control module is connected to the second isolation control device and the digital isolator respectively. The low-voltage power supply is connected to the low-voltage power conversion module and the communication chip respectively. The external communication signal is connected to the low-voltage power conversion module through the communication chip. The low-voltage power conversion module is connected to the digital isolator and the first isolation control device respectively. The communication chip is connected to the digital isolator. The first isolation control device and the second isolation control device are connected to the high-voltage control switch through an OR gate; wherein, The low-voltage power supply supplies power to the communication chip and the low-voltage power conversion module, and the low-voltage power conversion module provides a stable low-voltage side digital power supply for the digital isolator; The external communication signal communicates with the control module through the communication chip and the digital isolator in turn; the communication chip can enter a dormant state, and when the external communication signal wakes up the communication chip, the communication chip controls the low-voltage power conversion module, and then controls the first isolation control device to issue an opening instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to turn on, thereby achieving the communication wake-up function of the isolated communication system; After the high-voltage control switch is turned on, the control module controls the second isolation control device to send a power-on hold instruction to the high-voltage control switch, thereby controlling the high-voltage control switch to remain turned on; When the communication chip receives an external sleep command, the low-voltage power conversion module is powered off, and the first isolation control device is controlled to issue a first shutdown command to the high-voltage control switch. At this time, the control module needs to store data for a period of time to enter the shutdown sequence, and then controls the second isolation control device to issue a second shutdown command to the high-voltage control switch, thereby controlling the high-voltage control switch to shut down; wherein, after both the first isolation control device and the second isolation control device issue shutdown commands to the high-voltage control switch, the high-voltage control switch is turned off.

2. The isolated communication system with high voltage switch function according to claim 1, characterized in that: After the first isolation control device sends an opening instruction to the high-voltage control switch, the high-voltage control switch is turned on; after the second isolation control device sends a power-on holding instruction to the high-voltage control switch, the high-voltage control switch remains turned on.

3. The isolated communication system with high voltage switch function according to claim 1, characterized in that: When the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module generates a VDD voltage to supply power to the high-voltage side of the digital isolator and the control module respectively.

4. The isolated communication system with high voltage switch function according to claim 1, characterized in that: When the high-voltage control switch is turned on, the high-voltage power supply supplies power to the high-voltage power conversion module through the high-voltage control switch, so that the high-voltage power conversion module can supply power to the high-voltage load.

5. The isolated communication system with high voltage switch function according to claim 1, characterized in that: The high-voltage control switch is a relay RE1, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is a transistor Q1 and a first pin and a second pin of the relay RE1, the second isolation control device is an isolation optocoupler IC2, and the communication chip IC1 is integrated with the low-voltage power conversion module; the seventh pin of the relay RE1 is connected to the DC-DC converter, and the DC-DC converter is respectively connected to the first pin of the isolation optocoupler IC2 and the digital isolator IC3 through the MCU, the first pin of the relay RE1 is respectively connected to the collector of the transistor Q1 and the fourth pin of the isolation optocoupler IC2, the second pin of the relay RE1 is connected to the seventh pin of the communication chip IC1, and the base of the transistor Q1 is connected to the eighth pin of the communication chip IC1.

6. The isolated communication system with high voltage switch function according to claim 1, characterized in that: The high-voltage control switch includes a first switch tube Q3 and a second switch tube Q4, the high-voltage power conversion module is a DC-DC converter, the control module is an MCU, the first isolation control device is an isolation optocoupler IC4, the second isolation control device is a transistor Q5, and the low-voltage power conversion module is integrated in the communication chip IC5; the second pin of the first switch tube Q3 is connected to the high-voltage power supply, the second pin of the second switch tube Q4 is connected to the DC-DC converter, the DC-DC converter is respectively connected to the base of the transistor Q5 and the digital isolator IC6 through the MCU, the first pin of the first switch tube Q3 and the first pin of the second switch tube Q4 are respectively connected to the third pin of the isolation optocoupler IC4 and the collector of the transistor Q5 through a resistor R1, and the second pin of the isolation optocoupler IC4 and the eighth pin of the communication chip IC5 are both connected to the VCC voltage.

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