CN117639209A

CN117639209A - Dual-power isolation circuit and device

Info

Publication number: CN117639209A
Application number: CN202311527581.XA
Authority: CN
Inventors: 姚建伟
Original assignee: Jingwei Hengrun Tianjin Research And Development Co ltd
Current assignee: Jingwei Hengrun Tianjin Research And Development Co ltd
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2024-03-01

Abstract

The application discloses a dual power supply isolation circuit and device. The circuit comprises: the main path isolation module comprises a first switch, and two ends of the first switch are respectively connected with a first power supply and a second power supply; the bypass isolation module comprises a second switch and a current limiting resistor connected with the second switch in series, and two ends of the second switch are respectively connected with the first power supply and the second power supply; the logic control module is connected with the main path isolation module and the bypass isolation module and is used for controlling the second switch and the first switch to be sequentially conducted under the condition that the first power supply and the second power supply are electrified; and under the condition that the first power supply and the second power supply are powered down, the first switch is controlled to be turned off. According to the embodiment of the application, the protection capability of the isolation circuit can be improved in the isolation and communication process of the dual-power system, the damage risk is reduced, the complex working environment of the dual-power system is better adapted, and the robustness of the power system is improved.

Description

Dual-power isolation circuit and device

Technical Field

The application belongs to the technical field of power supplies, and particularly relates to a dual-power-supply isolation circuit and a device.

Background

With the continuous development of intelligent technology, the number of sensors, processors and actuators contained in various electric devices is also continuously improved. Taking an electric automobile as an example, in order to realize an automatic driving technology and ensure the safety of automatic driving, related electronic devices are increasingly arranged in the automobile.

In the running process of electric equipment, in order to ensure the normal running of devices, the related technology gradually develops to a double redundancy system, namely, the devices comprise a main device and a redundancy device. Accordingly, in order to achieve isolation between the main system and the redundant system, two sets of power supply systems, namely, a main power supply and a redundant power supply, are also required.

The two sets of power supply systems can be mutually communicated in normal operation, and are mutually disconnected in case of failure of one set of power supply systems so as to ensure that the system without failure can normally operate. For this reason, it is necessary to provide an isolation device between two power supply systems to switch between communication and isolation between the two power supply systems. However, the EOS (Electrical Over Stress ) generated by sudden changes in current and voltage will cause damage to the isolation device when the current isolation device is switched.

Disclosure of Invention

The embodiment of the application provides a dual-power isolation circuit and a device, which can solve the technical problem that an isolation device between two sets of power systems has damage risk when a switch state is changed.

In a first aspect, embodiments of the present application provide a dual power isolation circuit, the dual power isolation circuit comprising:

The main path isolation module comprises a first switch, and two ends of the first switch are respectively connected with a first power supply and a second power supply;

the bypass isolation module comprises a second switch and a current limiting resistor connected with the second switch in series, and two ends of the second switch are respectively connected with the first power supply and the second power supply;

the logic control module is connected with the main path isolation module and the bypass isolation module and is used for controlling the second switch and the first switch to be sequentially conducted under the condition that the first power supply and the second power supply are electrified; and under the condition that the first power supply and the second power supply are powered down, the first switch is controlled to be turned off.

In some embodiments, the main isolation module includes a first control unit, a first switch driving unit, and at least one of a first current detection unit, a voltage detection unit, or a first temperature sampling unit;

the first control unit is respectively connected with the first current detection unit and the voltage detection unit and is used for sending a turn-off signal to the first switch driving unit under the condition that at least one of an overcurrent signal, an overvoltage signal or an undervoltage signal is received;

the logic control module is connected with the first temperature sampling unit and is used for controlling the first control unit to send a turn-off signal to the first switch driving unit under the condition that the temperature signal meets the over-temperature condition.

In some embodiments, the first current detection unit includes:

the first sampling resistor is connected in series with the first switch;

the first operational amplifier is connected with two ends of the first sampling resistor and is used for amplifying the voltages of the two ends of the first sampling resistor to generate a current signal;

the first overcurrent detection device is connected with the first operational amplifier and is used for sending an overcurrent signal to the first control unit under the condition that the signal amplitude of the current signal meets the overcurrent threshold and the maintenance duration reaches the protection duration threshold.

In some embodiments, the voltage detection unit includes:

the first voltage detection device is connected with the first power supply and is used for acquiring a first power supply voltage of the first power supply, and sending an overvoltage signal or an undervoltage signal to the first control unit under the condition that the first power supply voltage does not meet a first voltage range;

the second voltage detection device is connected with a second power supply and used for acquiring a second power supply voltage of the second power supply, and sending an overvoltage signal or an undervoltage signal to the first control unit under the condition that the second power supply voltage does not meet a second voltage range.

In some embodiments, the bypass isolation module includes at least one of a second current detection unit or a second temperature sampling unit, a second switch driving unit, and a second control unit;

The second control unit is respectively connected with the second current detection unit and the voltage detection unit of the main circuit isolation module and is used for sending a turn-off signal to the second switch driving unit under the condition of receiving at least one of an overcurrent signal, an overvoltage signal or an undervoltage signal;

the logic control module is connected with the second temperature sampling unit and is used for controlling the second control unit to send a turn-off signal to the second switch driving unit under the condition that the temperature signal meets the over-temperature condition.

In some embodiments, the first switch comprises at least two pairs of MOSFETs in series, each pair of MOSFETs being connected in parallel with each other, the first pole of the body diode of one of each pair of MOSFETs being connected to the first pole of the body diode of the other pair of MOSFETs;

the first switch driving unit comprises a first gate driving unit and a second gate driving unit, the first gate driving unit is used for driving a first MOSFET in each pair of MOSFETs, and the second gate driving unit is used for driving a second MOSFET in each pair of MOSFETs; the anode of the body diode of the first MOSFET is connected with a first power supply, and the anode of the body diode of the second MOSFET is connected with a second power supply;

the first temperature sampling unit comprises a plurality of thermistors, and each thermistor is connected with the logic control module and used for detecting the working temperature of the corresponding MOSFET.

In some embodiments, the first current detection unit is configured to detect a bidirectional current signal between the first power source and the second power source;

the first control unit is used for sending a turn-off signal to the second grid driving unit under the condition of receiving an overcurrent signal from the first power supply to the second power supply, an overvoltage signal of the first power supply or an undervoltage signal of the second power supply; and sending a turn-off signal to the first gate driving unit when receiving an overcurrent signal from the second power supply to the first power supply, an overvoltage signal of the second power supply or an undervoltage signal of the first power supply.

In some embodiments, the logic control module comprises:

the power taking unit comprises a first diode and a second diode, wherein the anode of the first diode is connected with a first power supply, and the anode of the second diode is connected with a second power supply;

the power supply end of the power supply management unit is connected with the cathode of the first diode and the cathode of the second diode, and the power supply management unit is used for providing power supply voltage and a power-on signal;

the main control unit is connected with the power management unit, the first current detection unit, the second current detection unit and the voltage detection unit, and is used for sending a conduction signal to the second switch under the condition that a power-on signal is received, and sending the conduction signal to the first switch under the condition that the voltage difference value between the first power supply and the second power supply is smaller than a voltage difference threshold value.

In some embodiments, the overcurrent threshold of the first current detection unit is greater than the overcurrent threshold of the second current detection unit, and the protection duration threshold of the first current detection unit is less than the protection duration threshold of the second current detection unit.

In a second aspect, embodiments of the present application provide a dual power isolation device including the dual power isolation circuit of the first aspect.

Compared with the prior art, the dual-power isolation circuit and the device provided by the embodiment of the application have the advantages that the main circuit isolation module and the bypass isolation module are arranged, the main circuit isolation module has larger through-current capacity, and the current limiting resistor arranged by the bypass isolation module can generate larger current limiting capacity. When the dual-power system is electrified, the second switch can be conducted in advance, and the first switch is conducted after the pressure difference of the two power supplies is stable, so that redundant power supply between the dual power supplies is realized through the main circuit isolation module after the bypass isolation module resists larger pressure difference impact. When the dual-power system is powered down, the first switch can be disconnected, and the second switch is kept on, so that the two power supplies are kept in communication through the bypass isolation module, and large instant current cannot be generated when the two power supplies are in communication. When one of the power supplies of the dual-power supply system fails, the first switch can be disconnected firstly, and then the second switch is disconnected, so that the transient impact is avoided in the disconnection process of the two power supplies. The main isolation module and the bypass isolation module are arranged to realize the communication and isolation of the dual power supply, so that the protection capability of an isolation part in the dual power supply system can be greatly increased, the damage risk is reduced, the complex working environment of the dual power supply system is better adapted, and the robustness of the power supply system is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic block diagram of a dual power isolation circuit according to an embodiment of the present disclosure;

FIG. 2 is a schematic block diagram of a dual power isolation circuit according to another embodiment of the present disclosure;

FIG. 3 is a schematic block diagram of a dual power isolation circuit according to another embodiment of the present disclosure;

FIG. 4 is a schematic block diagram of a dual power isolation circuit according to another embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a dual power isolation circuit according to an embodiment of the present disclosure;

fig. 6 is a schematic circuit diagram of a dual-power isolation circuit according to an embodiment of the present application.

In the accompanying drawings:

10. a main way isolation module; 20. a bypass isolation module; 30. a logic control module; 40. a first power supply; 50. a second power supply; s1, a first switch; s2, a second switch; rc, current limiting resistor; 11. a first current detection unit; 12. a voltage detection unit; 13. a first temperature sampling unit; 14. a first switch driving unit; 15. a first control unit; rs1, a first sampling resistor; OP1, a first operational amplifier; OC1, a first overcurrent detection device; rs2, a second sampling resistor; OP2, a second operational amplifier; OC2, a second overcurrent detection device; OV1, a first voltage detection device; OV2, a second voltage detection device; 21. a second current detection unit; 22. a second temperature sampling unit; 23. a second switch driving unit; 24. a second control unit; m1, a first MOSFET; m2, a second MOSFET; GD1, first gate drive unit; GD2, a second gate drive unit; GD3, third gate drive unit; an NTC and a thermistor; 31. a power taking unit; d1, a first diode; d2, a second diode; 32. a power management unit; 33. and a main control unit.

Detailed Description

Features and exemplary embodiments of various aspects of the present application are described in detail below to make the objects, technical solutions and advantages of the present application more apparent, and to further describe the present application in conjunction with the accompanying drawings and the detailed embodiments. It should be understood that the specific embodiments described herein are intended to be illustrative of the application and are not intended to be limiting. It will be apparent to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by showing an example of the present application.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

The two sets of power supply systems can be mutually communicated in normal operation, and are mutually disconnected in case of failure of one set of power supply systems, so that the normal operation of the system which does not fail is ensured. For this reason, it is necessary to provide an isolation device between two power supply systems to switch between communication and isolation between the two power supply systems. However, the EOS (Electrical Over Stress ) generated by sudden changes in current and voltage will cause damage to the isolation device when the current isolation device is switched.

In order to solve the technical problems, embodiments of the present application provide a dual-power isolation circuit and a device. The following first describes a dual power isolation circuit provided in an embodiment of the present application.

Fig. 1 shows a schematic structure of a dual power isolation circuit according to an embodiment of the present application. The dual power isolation circuit includes a main isolation module 10, a bypass isolation module 20, and a logic control module 30.

The main isolation module 10 includes a first switch S1, and two ends of the first switch S1 are connected to the first power source 40 and the second power source 50, respectively. When the first switch S1 is turned on, the first power source 40 and the second power source 50 may communicate through the first switch S1.

The bypass isolation module 20 includes a second switch S2 and a current limiting resistor Rc connected in series with the second switch S2, where two ends of the second switch S2 are connected to the first power source 40 and the second power source 50, respectively. The number of the current limiting resistors Rc may be one or more, and the current limiting resistors Rc may be disposed between the first power source 40 and the second switch S2, or may be disposed between the second power source 50 and the second switch S2. When the number of the current limiting resistors Rc is plural, a part of the current limiting resistors Rc may be provided between the first power source 40 and the second switch S2, and another part may be provided between the second power source 50 and the second switch S2.

When the second switch S2 is turned on, the first power source 40 and the second power source 50 may communicate through the second switch S2. Because the current loop where the second switch S2 is located is provided with the current limiting resistor Rc, the second switch S2 can resist larger voltage difference impact compared with the first switch S1, and the first switch S1 has stronger current capacity compared with the second switch S2.

The logic control module 30 may be connected to the main path isolation module 10 and the bypass isolation module 20, respectively. When the first power supply 40 and the second power supply 50 are powered on, the logic control module 30 can control the second switch S2 to be turned on first, and at this time, the current limiting resistor Rc in the bypass isolation module 20 can avoid excessive transient current impact generated in the process of connecting the first power supply 40 and the second power supply 50. After the first power source 40 is connected to the second power source 50 through the second switch S2, the voltage difference between the power source voltages at the two ends is gradually reduced, and after the voltage difference is reduced to a certain range, the logic control module 30 may conduct the first switch S1. Since the voltage difference between the two power supplies is small at this time, no large transient impact is generated to the main isolation module 10.

In the dual power system, one of the first power source 40 and the second power source 50 is a main power source, and the other is a redundant power source. Taking the first power source 40 as a main power source, the first power source 40 needs to supply power to the main load 41, and the second power source 50 needs to supply power to the redundant load 51. In the event of a failure of one of the power supplies of the dual power supply system, the corresponding load needs to be supplied by the other power supply. For example, when the first power supply 40 (main power supply) fails, the second power supply 50 (redundant power supply) needs to supply power not only to the redundant load 51 but also to the main load 41. And the second power supply 50 supplies power to the main load 41 through the isolation module, the isolation module is required to have a strong current-through capability. Therefore, after the logic control module 30 turns on the second switch S2 first and determines that the first power source 40 and the second power source 50 are relatively stable, the first switch S1 may be turned on. When the first switch S1 is turned on and one of the first power supply 40 and the second power supply 50 fails, the main isolation module 10 can meet the requirement of larger current passing, so that the power supply which does not fail can supply power to the load corresponding to the failed power supply.

When the dual power system is powered down or dormant, the logic control module 30 may open the first switch S1 to reduce the quiescent current in the dual power system, where the second switch S2 maintains a closed state, and the first power source 40 and the second power source 50 may maintain the communication through the second switch S2 in the powered down state or dormant state.

When one of the first power source 40 or the second power source 50 has a short circuit fault, the logic control module 30 may control the first switch S1 and the second switch S2 to be turned off, so as to isolate the first power source 40 from the second power source 50, and avoid the short circuit power source affecting the other power source and the load supplied by the other power source.

Taking the short-circuit fault of the first power supply 40 as an example, since the current capacity of the main circuit isolation module 10 is strong, in order to avoid the influence of the instantaneous current on the second power supply 50, the main circuit isolation module 10 should be turned off quickly, i.e. when the short-circuit fault of the first power supply 40 occurs, the first switch S1 should be turned off quickly. Since the bypass isolation module 20 is provided with the current limiting resistor Rc, an excessive instantaneous current can be avoided, and a certain time can be prolonged for response when the first power supply 40 has a short-circuit fault. That is, after the first switch S1 is turned off, if a fault still exists, the second switch S2 may be turned off at this time, so that the first power source 40 is completely isolated from the second power source 50.

According to the current-passing capability of the main isolation module 10 and the current-limiting capability of the bypass isolation module 20, when the first power source 40 and the second power source 50 need to be communicated, the second switch S2 can be turned on, and then the first switch S1 can be turned on. When the first power source 40 and the second power source 50 need to be isolated, the second switch S2 may be turned off first, and then the first switch S1 may be turned off. On the basis that the main isolation module 10 is utilized to meet the current required by the mutual power supply of the dual-power system, the current limiting effect of the bypass isolation module 20 can be utilized to reduce the impact of instantaneous EOS in the process of communication and isolation, so that the operation safety of the dual-power system is ensured.

In this embodiment, by providing the main path isolation module 10 and the bypass isolation module 20, the main path isolation module 10 has a larger current-limiting capability, and the current-limiting resistor Rc provided by the bypass isolation module 20 can generate a larger current-limiting capability. When the dual power supply system is electrified, the second switch S2 can be led in, and the first switch S1 is led in after the pressure difference of the two power supplies is stable, so that redundant power supply between the dual power supplies is realized through the main circuit isolation module 10 after the bypass isolation module 20 resists larger pressure difference impact. When the dual power system is powered down, the first switch S1 can be turned off, and the second switch S2 is maintained to be turned on, so that the two power supplies are maintained to be communicated through the bypass isolation module 20, and the two power supplies do not generate larger instantaneous current during the communication. The main path isolation module 10 and the bypass isolation module 20 are arranged to realize the communication and isolation of the dual power supply, so that the protection capability of an isolation part in the dual power supply system can be greatly increased, the complex working environment of the dual power supply system can be better adapted, and the robustness of the power supply system is improved.

Referring to fig. 2, in some embodiments, the main isolation module 10 may include at least one of a first current detection unit 11, a voltage detection unit 12, or a first temperature sampling unit 13, and the main isolation module 10 may further include a first switch driving unit 14 and a first control unit 15.

The first current detection unit 11 can detect the current of the loop where the first switch S1 is located, so as to obtain a current signal. The voltage detection unit 12 may detect the power supply voltages of the first power supply 40 and the second power supply 50 connected to the first switch S1 unit to obtain a voltage signal.

The first control unit 15 may be connected to the first current detection unit 11 and the voltage detection unit 12, respectively, and the first current detection unit 11 may send an overcurrent signal to the first control unit 15 when the magnitude of the detected current signal is too large at the time of current detection.

When the voltage detection unit 12 detects the voltage of the first power source 40 or the second power source 50, if the detected voltage is too large or too small, an overvoltage signal or an undervoltage signal may be sent to the first control unit 15.

The first control unit 15 may transmit a turn-off signal to the first switch driving unit 14 upon receiving at least one of an overcurrent signal, an overvoltage signal, or an undervoltage signal.

The first switch driving unit 14 can control the on state of the first switch S1, and when the first switch driving unit 14 receives the off signal, the first switch S1 may be turned off. When the first switch driving unit 14 receives the on signal, the first switch S1 may be turned on.

When the main circuit isolation module 10 is provided with the first current detection unit 11, the first switch S1 may be turned off when the current loop where the main circuit isolation module 10 is located is too large, so as to implement an overcurrent protection function. When the main circuit isolation module 10 is provided with the voltage detection unit 12, the first switch S1 unit can be disconnected when the voltage of at least one of the two power supplies is too large or too small, so as to realize an overvoltage protection function or an undervoltage protection function.

The logic control module 30 may be connected to the first temperature sampling unit 13, when the main circuit isolation module 10 operates, the first temperature sampling unit 13 may detect an operating temperature of the main circuit isolation module 10, and the logic control module 30 may obtain a temperature signal collected by the first temperature sampling unit 13 and determine whether the operating temperature of the main circuit isolation module 10 is too high according to the temperature signal. When the temperature signal meets the over-temperature condition, the logic control module 30 may determine that the temperature of the main circuit isolation module 10 is higher, and at this time, the logic control module 30 may control the first control unit 15 to send an off signal to the first switch driving unit 14 to open the first switch S1. That is, when the main path isolation module 10 is provided with the first temperature sampling unit 13, the first switch S1 unit may be turned off when the temperature of the main path isolation module 10 is too high, thereby realizing an overheat protection function.

Through setting up first electric current detecting element 11, voltage detecting element 12 or first temperature sampling unit 13, can realize overcurrent protection, overvoltage protection, undervoltage protection or overtemperature protection respectively, promote the adaptability of dual supply isolation circuit under various complex environments.

Referring to fig. 3, in some embodiments, the first current detecting unit 11 may include a first sampling resistor Rs1, a first operational amplifier OP1, and a first over-current detecting device OC1.

The first sampling resistor Rs1 may be connected in series with the first switch S1. The two input ends of the first operational amplifier OP1 may be connected to two ends of the first sampling resistor Rs1, respectively, and the first operational amplifier OP1 may obtain a voltage difference value between two ends of the first sampling resistor Rs1 and amplify the voltage difference value to generate a current signal.

The first over-current detection device OC1 may be connected to an output terminal of the first operational amplifier OP1, the first operational amplifier OP1 may output a current signal to the first over-current detection device OC1, and the first over-current detection device OC1 may determine, according to the current signal, a current signal amplitude of a loop in which the main circuit isolation module 10 is located. When the current signal amplitude reaches the overcurrent threshold and is maintained for a certain period of time, for example, the maintenance period of time reaches the protection period of time threshold, an overcurrent protection function may be triggered, and an overcurrent signal is sent to the first control unit 15, so that the first control unit 15 turns off the first switch S1.

Since the main circuit isolation module 10 is not provided with the current limiting resistor Rc with a larger resistance value, the main circuit isolation module 10 has weak current limiting capability, and needs to perform quick response when overcurrent occurs. The guard period threshold may be set to a shorter period, for example the guard period threshold may be us level. Accordingly, the bypass isolation module 20 is provided with a current limiting resistor Rc, so that when overcurrent occurs, in order to increase the stability of the dual-power system, the response time of the overcurrent protection can be prolonged appropriately, for example, the protection duration threshold can be in ms level.

Accordingly, since the current capacity of the main circuit isolation module 10 is strong, the current threshold of the main circuit isolation module 10 may be set to be greater than the current threshold of the bypass isolation module 20.

With continued reference to fig. 3, in some embodiments, the voltage detection unit 12 may include a first voltage detection device OV1 and a second voltage detection device OV2.

The first voltage detection device OV1 may be connected to the first power source 40 to obtain a first power source voltage of the first power source 40.

The second voltage detection device OV2 may be connected to the second power source 50 to obtain a second power source voltage of the second power source 50.

The first voltage detection device OV1 may compare the first power supply voltage with the first voltage range after acquiring the first power supply voltage, and when the first power supply voltage does not satisfy the first voltage range, the first voltage detection device OV1 may transmit an overvoltage signal or an undervoltage signal to the first control unit 15. For example, the first voltage detection device OV1 may transmit an under-voltage signal when the first power supply voltage is below the first voltage range; the first voltage detection device OV1 may send an overvoltage signal when the first power supply voltage is above the first voltage range.

The first voltage range may be determined according to a normal fluctuation range of the first power supply voltage, that is, a maximum voltage value of the first voltage range may be slightly greater than a maximum voltage value of the first power supply voltage under normal conditions, and a minimum voltage value of the first voltage range may be slightly less than a minimum voltage value of the first power supply voltage under normal conditions. For example, when the voltage amplitude of the first power supply voltage is in the 8V-16V interval, the first voltage range may be determined to be in the 7V-16V interval. At this time, if the first power supply voltage is within the normal voltage amplitude range, the first voltage detection device OV1 will not generate the overvoltage signal or the undervoltage signal, and when the first power supply voltage exceeds the first voltage range, the first voltage detection device OV1 may send the overvoltage signal or the undervoltage signal.

Likewise, the second voltage detection device OV2 may compare the second power supply voltage with the second voltage range after acquiring the second power supply voltage, and when the second power supply voltage does not satisfy the second voltage range, the second voltage detection device OV2 may transmit an overvoltage signal or an undervoltage signal to the first control unit 15.

Since the voltage difference between the power supply voltages of the first power supply 40 and the second power supply 50 is small in the dual power supply system, the voltage amplitude interval of the second power supply voltage generally coincides with the voltage amplitude interval of the first power supply voltage. At this time, the second voltage range may be set alone according to the voltage fluctuation range of the second power supply voltage, or may be kept identical to the first voltage range.

By providing the first voltage detection device OV1 and the second voltage detection device OV2, when the voltage of the first power supply 40 or the second power supply 50 is abnormal in overvoltage or undervoltage, the first switch S1 can be turned off by the first control unit 15, so as to realize overvoltage protection and undervoltage protection.

As an alternative embodiment, the first voltage detecting device OV1 may include a comparator capable of comparing the first power voltage of the first power source 40 with a preset first voltage range, and a latch capable of latching a fault signal of an overvoltage or an undervoltage when the first power voltage exceeds an upper limit of the preset range or is lower than a lower limit of the preset range, so that the first control unit 15 continuously receives the overvoltage signal or the undervoltage signal, so that the first switch S1 can be opened and maintain an opened state.

Referring to fig. 4, in some embodiments, the bypass isolation module 20 may include at least one of a second current detection unit 21 or a second temperature sampling unit 22, and the bypass isolation module 20 may further include a second switch driving unit 23 and a second control unit 24.

The second current detecting unit 21 may include a second sampling resistor Rs2, a second operational amplifier OP2, and a second overcurrent detecting device OC2, similar to the first current detecting unit 11.

The second control unit 24 is connected to the second current detection unit 21 and the voltage detection unit 12 of the main isolation module 10, respectively.

The second current detection unit 21 can detect the current of the loop where the second switch S2 is located, so as to obtain a current signal. When the second current detection unit 21 detects a current, if the detected current signal has an excessive amplitude, an overcurrent signal may be sent to the second control unit 24.

Since the main path isolation module 10 and the bypass isolation module 20 are both connected to the first power source 40 and the second power source 50, the second control unit 24 in the bypass isolation module 20 may be directly connected to the voltage detection unit 12 of the main path isolation module 10 on the basis that the voltage detection unit 12 is provided in the main path isolation module 10. When the voltage detection unit 12 detects the voltage of the first power source 40 or the second power source 50, if the detected voltage is too large or too small, an overvoltage signal or an undervoltage signal may be sent to both the first control unit 15 and the second control unit 24.

The second control unit 24 may transmit a turn-off signal to the second switch driving unit 23 upon receiving at least one of an overcurrent signal, an overvoltage signal, or an undervoltage signal.

The second switch driving unit 23 can control the on state of the second switch S2, and when the second switch driving unit 23 receives the off signal, the second switch S2 can be turned off. When the second switch driving unit 23 receives the on signal, the second switch S2 may be turned on.

The logic control module 30 may be connected to the second temperature sampling unit 22, and when the bypass isolation module 20 operates, the second temperature sampling unit 22 may detect an operating temperature of the bypass isolation module 20, and the logic control module 30 may obtain a temperature signal collected by the second temperature sampling unit 22 and determine whether the operating temperature of the bypass isolation module 20 is too high according to the temperature signal. When the temperature signal satisfies the over-temperature condition, the logic control module 30 may determine that the temperature of the bypass isolation module 20 is high, and at this time, the logic control module 30 may control the second control unit 24 to send an off signal to the second switch driving unit 23 to open the second switch S2. That is, when the bypass isolation module 20 is provided with the second temperature sampling unit 22, the second switch S2 unit may be turned off when the temperature of the bypass isolation module 20 is too high, thereby realizing an overheat protection function.

By providing the second current detecting unit 21 and the second temperature sampling unit 22, the overcurrent protection or the overtemperature protection can be realized respectively.

In some embodiments, the first switch S1 may include at least two pairs of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor) connected in series, and each pair of MOSFETs is connected in parallel to each other. As other embodiments, the first switch S1 may be another type of transistor. The first pole of the body diode of one of each pair of MOSFETs is connected to the first pole of the body diode of the other. That is, in each pair of MOSFETs, the cathode of one body diode is connected to the cathode of the other body diode, or the anode of one body diode is connected to the anode of the other body diode.

The two MOSFETs in each set of the opposite series connection may be N-channel MOSFETs, and when both MOSFETs are turned off, the first power source 40 and the second power source 50 are not connected; when both MOSFETs are on, the first power supply 40 and the second power supply 50 are in bidirectional communication; when one of the two MOSFETs is turned on, the turned-on MOSFET and the body diode of the other turned-off MOSFET form a unidirectional conduction loop, so that the first power supply 40 and the second power supply 50 are in unidirectional communication.

Referring to fig. 5, the first switch driving unit 14 may include a first gate driving unit GD1 and a second gate driving unit GD2.

Each pair of MOSFETs may include a first MOSFET and a second MOSFET, as shown in fig. 5, M1 being the first MOSFET and M2 being the second MOSFET. The anode of the body diode of the first MOSFET is connected to a first power supply 40 and the anode of the body diode of the second MOSFET is connected to a second power supply 50.

When the cathode of the first MOSFET is connected to the cathode of the second MOSFET, the anode of the first MOSFET is directly connected to the first power supply 40, and the anode of the second MOSFET is directly connected to the second power supply 50; when the anode of the first MOSFET is connected to the anode of the second MOSFET, the anode of the first MOSFET is connected to the first power supply 40 via the second MOSFET, and the anode of the second MOSFET is connected to the second power supply 50 via the first MOSFET.

The first gate driving unit GD1 may be connected to the first MOSFETs of each pair of MOSFETs to drive the respective first MOSFETs to be turned on or off synchronously. The second gate driving unit GD2 may be connected to the second MOSFETs of each pair of MOSFETs to drive the respective second MOSFETs to be turned on or off synchronously.

The first temperature sampling unit 13 may include a plurality of thermistors NTC, each of which may be disposed beside a corresponding MOSFET and connected with the logic control module 30. When the working temperature of the corresponding MOSFET changes, the resistance of the thermistor NTC can change correspondingly, and the logic control module 30 connected with the thermistor NTC can determine the resistance of the thermistor NTC according to the signal amplitude of the received sampling signal, thereby determining the working temperature of the corresponding MOSFET.

The logic control module 30 is respectively connected with a plurality of thermistors NTC through a plurality of sampling ends, so that the working temperatures of the MOSFETs can be respectively obtained, and temperature monitoring is realized.

When the operating temperature of the MOSFET is too high, the logic control module 30 may send a corresponding adjustment signal to the first control unit 15, so that the first control unit 15 controls the first switch driving unit 14 to turn off the first switch S1.

Corresponding to the main isolation module 10, in the bypass isolation module 20, the second switch S2 may include a pair of MOSFETs in series, similar to each pair of MOSFETs in the first switch S1. The second switch driving unit 23 may include a third gate driving unit GD3, and the third gate driving unit GD3 is connected to the gates of the pair of MOSFETs connected in series, and is capable of driving the pair of MOSFETs to be turned on or off.

The second temperature sampling unit 22 may include a thermistor NTC disposed beside the second switch S2, which is also connected with the logic control module 30. The logic control module 30 may transmit an off signal to the third switch driving unit through the second control unit 24 to turn off a pair of MOSFETs in the second switch S2 when it is determined that the temperature of the second switch S2 is too high according to the sampling signal of the thermistor NTC.

In some embodiments, the first current detection unit 11 may detect a bidirectional current signal between the first power source 40 and the second power source 50, that is, when there is an overcurrent in a direction from the first power source 40 to the second power source 50, the first current detection unit 11 may generate a first overcurrent signal; and when there is an overcurrent in the direction from the second power source 50 to the first power source 40, the first current detection unit 11 may generate a second overcurrent signal.

The first control unit 15 may transmit an off signal to the second gate driving unit GD2 when receiving a first overcurrent signal in a direction from the first power source 40 to the second power source 50, at which time a first MOSFET of each pair of MOSFETs is turned on and a second MOSFET is turned off.

When the first MOSFET is turned on and the second MOSFET is turned off, the body diode of the second MOSFET and the first MOSFET form an on-loop, and when overcurrent occurs in a direction from the first power supply 40 to the second power supply 50, the body diode of the second MOSFET is turned off by reverse bias, so that current can be limited.

Conversely, the first control unit 15 may transmit an off signal to the first gate driving unit GD1 when receiving the second overcurrent signal in the direction from the second power supply 50 to the first power supply 40, at which time the second MOSFET of each pair of MOSFETs is turned on and the first MOSFET is turned off. The body diode of the first MOSFET and the second MOSFET form a conducting loop. Since the anode of the body diode of the first MOSFET is connected to the second power supply 50, the body diode of the first MOSFET is turned off in reverse bias, and thus, an excessive current can be current-limited.

When the first power supply voltage of the first power supply 40 is over-voltage, a voltage difference exists between the first power supply 40 and the second power supply 50, the loads on the first power supply 40 side and the second power supply 50 side are powered by the first power supply 40 with higher voltage, at this time, load current on the second power supply 50 side will flow through the isolation module, and when the isolation module bears large current, a larger overheat risk exists. The first control unit 15 may transmit an off signal to the second gate driving unit GD2 upon receiving the overvoltage signal of the first power source 40, so that the body diode of the second MOSFET is turned off in reverse bias. At this time, the first power source 40 and the second power source 50 are turned on in one direction from the second power source 50 to the first power source 40, and the overvoltage of the first power source 40 does not flow to the second power source 50.

Similarly, when the second power supply voltage of the second power supply 50 is undervoltage, there is a voltage difference between the first power supply 40 and the second power supply 50, and the loads on the first power supply 40 side and the second power supply 50 side are also powered by the first power supply 40 with higher voltage, at this time, the first control unit 15 may send an off signal to the second gate driving unit GD2 when receiving the undervoltage signal of the second power supply 50, so as to turn off the body diode of the second MOSFET reversely.

In combination with the above embodiments, when the first power source 40 and the second power source 50 are over-current, the first power source 40 is over-voltage, or the second power source 50 is under-voltage, the first control unit 15 may send a turn-off signal to the second gate driving unit GD2, so that the first power source 40 and the second power source 50 are unidirectional on in a direction from the second power source 50 to the first power source 40, thereby realizing over-current protection, over-voltage protection, or under-voltage protection.

Correspondingly, when the second power supply 50 is over-current in the direction from the first power supply 40, the second power supply 50 is over-voltage or the first power supply 40 is under-voltage, the first control unit 15 may send a turn-off signal to the first gate driving unit GD1 according to the received second over-current signal from the second power supply 50 to the first power supply 40, the received over-voltage signal from the second power supply 50 or the received under-voltage signal from the first power supply 40, so that the first power supply 40 and the second power supply 50 are unidirectional on in the direction from the first power supply 40 to the second power supply 50, thereby realizing over-current protection, over-voltage protection or under-voltage protection.

With continued reference to fig. 5, in some embodiments, the logic control module 30 may include a power taking unit 31, a power management unit 32, and a main control unit 33.

The power taking unit 31 may include a first diode D1 and a second diode D2, wherein an anode of the first diode D1 is connected to the first power source 40, and an anode of the second diode D2 is connected to the second power source 50.

The power supply terminal of the power management unit 32 is connected to the cathode of the first diode D1 and the cathode of the second diode D2. In the case where at least one of the first power source 40 and the second power source 50 is powered on, the power management unit 32 can receive the power supply voltage, and one of the two diodes is in an on state, and the other is in a reverse bias off state, so that the power supply voltage can be prevented from being applied to the load on the other side through the diode.

The power management unit 32 can generate a power supply voltage and supply it to the main control unit 33. The power management unit 32 is also capable of generating a power-on signal upon receiving the power supply voltage of the first power supply 40 or the second power supply 50.

The main control unit 33 may be connected to the power management unit 32, the first current detection unit 11, the second current detection unit 21, and the voltage detection unit 12, respectively.

When the power management unit 32 outputs the power-on signal, the main control unit 33 may transmit a turn-on signal to the second switch S2 according to the power-on signal to turn on the second switch S2. When the second switch S2 is turned on, the first power supply 40 and the second power supply 50 are connected through the bypass isolation module 20, so that the current on the loop can be limited, and the transient current surge when the first power supply 40 and the second power supply 50 are connected is avoided.

After the first power source 40 and the second power source 50 are connected through the bypass isolation module 20, when the voltage difference between the first power source 40 and the second power source 50 is smaller than the voltage difference threshold, the main control unit 33 may send a conducting signal to the first switch S1 to conduct the first switch S1. When the first switch S1 is turned on, the first power supply 40 and the second power supply 50 are connected through the main path isolation module 10, the main path isolation module 10 has higher current-through capability, and redundant power supply of the dual-power system can be realized, that is, when one of the two power supplies fails, the other power supply can supply power for a load corresponding to the failed power supply, and the main path isolation module 10 can meet load current required by power supply for the load on the failed side.

In some embodiments, the overcurrent threshold of the first current detection unit 11 may be set to be greater than the overcurrent threshold of the second current detection unit 21, and the protection duration threshold of the first current detection unit 11 may be set to be smaller than the protection duration threshold of the second current detection unit 21.

It should be noted that the first switch S1 has a strong current-limiting capability, and the second switch S2 has a strong current-limiting capability. For the main circuit isolation module 10 with low current limiting or non-limiting capability, in order to avoid excessive impact of instantaneous current, a quick response is required when overcurrent occurs, that is, the protection duration threshold of the first current detection unit 11 is small, so that overcurrent protection can be quickly performed.

Likewise, the first switch S1 has a strong current-passing capability, and the current flowing through the main isolation module 10 where the first switch S1 is located is generally much larger than that flowing through the bypass isolation module 20 where the second switch S2 is located. Therefore, the overcurrent threshold at which the first current detection unit 11 triggers the overcurrent protection should be larger than the overcurrent threshold at which the second current detection unit 21 triggers the overcurrent protection.

As an alternative embodiment, the overcurrent threshold of the first current detecting unit 11 may be 250A, and the overcurrent threshold of the second current detecting unit 21 may be 30A; the protection duration threshold of the first current detection unit 11 may be 50us and the protection duration threshold of the second current detection unit 21 may be 200ms. Accordingly, the preset differential voltage threshold Δv may be 2V, that is, the second switch S2 may be turned on when the absolute value of the voltage difference between the first power supply 40 and the second power supply 50 is less than 2V.

Referring to fig. 6, in some embodiments, the dual power isolation circuit may further include a first capacitor, a second capacitor, a first TVS (Transient voltage suppression ) diode, and a second TVS diode. In fig. 6, c3_1 is a first capacitor, c3_2 is a second capacitor, q3_1 is a first TVS diode, and q3_2 is a second TVS diode.

A first end of the first capacitor is connected between the first switch S1 and the first power supply 40, and a second end of the first capacitor is grounded; the first end of the second capacitor is connected between the first switch S1 and the second power supply 50, and the second end of the second capacitor is grounded. The first capacitor and the second capacitor may be ESD (electrostatic discharge) capacitors, and the number of the first capacitor and the second capacitor may be one or more, and the capacitance values of the respective capacitors may be the same or different.

A first end of the first TVS diode is connected between the first switch S1 and the first power supply 40, and a second end of the first TVS diode is grounded; the first terminal of the first TVS diode is connected between the first switch S1 and the second power supply 50, and the second terminal of the first TVS diode is grounded.

And a capacitor is arranged between the first switch S1 and the two power supplies, so that voltage signals provided by the power supplies can be filtered, and the influence of interference signals is reduced. The TVS diode can be used for shunting when the transient current is overlarge so as to avoid damage to devices in the circuit caused by overlarge peak current.

As an alternative embodiment, as shown in fig. 6, node a is the power supply terminal of the first power source 40, and node B is the power supply terminal of the second power source 50.

In the main isolation module 10, q1_1 and q2_1 are a pair of oppositely disposed N-channel MOSFETs, and the first switch S1 includes N pairs of MOSFETs. R3 is a first sampling resistor, U1_1 is a first operational amplifier, and the voltage at two ends of R3 can be amplified.

The u2_2 is a comparator and a latch, and can compare the amplified current signal with an overcurrent threshold value and output an overcurrent signal OCA or an overcurrent signal OCB when the current is excessive. The OCA is that the current in the direction from node a to node B is excessive, and the OCB is that the current in the direction from node B to node a is excessive.

The U2_1 is a comparator and a latch, can detect and compare the power supply voltage of the first power supply 40, and can output an overvoltage signal OVA when the voltage of the first power supply 40 is overlarge; when the voltage of the first power source 40 is too small, the u2_1 may output the under-voltage signal UVA.

Likewise, u2_3 can detect and compare the supply voltage of the second power supply 50, and when the voltage of the second power supply 50 is too large, u2_3 can output an overvoltage signal OVB; when the voltage of the second power supply 50 is too small, the u2_3 may output the under-voltage signal UVB.

The u4_2 is a logic or gate, and when at least one of the over-current signal OCA, the over-voltage signal OVA, and the under-voltage signal UVB is an active signal, the u4_2 can output a hw_fault signal to the u4_3.

And U4-3 is a logic OR gate and is respectively connected with U6 and U4-2. U6 is the main control unit 33, for example, may be an MCU (Microcontroller Unit, micro control unit), U6 may output an enable signal to u4_3, and when u4_2 outputs a hw_fault signal or U6 outputs an enable signal, u4_3 may output an EN signal to u3_1, and u3_1 is the first gate driving unit GD1.

Similarly, u4_4 is a logical or gate, connected to U6 and u4_2, respectively. When at least one of the over-current signal OCB, the over-voltage signal OVB, and the under-voltage signal UVA is an active signal, u4_2 can output a hw_fault signal to u4_4. When the u4_2 outputs the hw_fault signal or the U6 outputs the enable signal, the u4_4 may output the EN signal to the u3_2, and the u3_2 is the second gate driving unit GD2.

In the bypass isolation module 20, the first switch S1 includes q4_1 and q4_2, q4_1 and q4_2 are a pair of oppositely disposed N-channel MOSFETs, R6 is a second sampling resistor, R4, R5, R7, R8 are current limiting resistors, and u1_2 is a second operational amplifier capable of amplifying the voltage across R6.

The u2_4 is a comparator and a latch, and can compare the amplified current signal with an overcurrent threshold value and output an overcurrent signal OCC or an overcurrent signal OCD when the current is excessive. The OCC is that the current in the direction from node A to node B is too large, and the OCD is that the current in the direction from node B to node A is too large.

The u4_1 is a logic or gate, and when at least one of the over-current signal OCC and the over-voltage signal OVA is an active signal, the u4_1 can output an active signal to the u4_5. And U4-5 is a logic OR gate and is respectively connected with U6 and U4-1. When at least one of the u4_1 and the U6 outputs the active signal, the u4_5 can output the off signal to the u3_3, and the u3_3 is the third gate driving unit GD3.

In the logic control module 30, the U5 is a power management unit 32, for example, may be an SBC (System Basic Chip, power management chip), and the U5 may provide corresponding power supply voltages for each of the above modules and chips when at least one of the first power source 40 or the second power source 50 is powered on. U5 may also be in communication with U6.

The U6 may also be in communication connection with the u2_1, the u2_2, and the u3_3, where the U6 may sample the electrical parameter signals of each node, and after the first switch S1 in the main circuit isolation module 10 is turned off, if the U6 determines that the fault has been eliminated, a Retry signal may be sent to the u2_1, the u2_2, or the u3_3 to stop outputting an overcurrent signal, an overvoltage signal, or an undervoltage signal, so that the MOSFET turned off in the first switch S1 is turned back on.

The embodiment of the application also provides a dual-power isolation device, which can comprise the dual-power isolation circuit provided by the embodiment of the application.

The functional blocks shown in the above-described structural block diagrams may be implemented in hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the present application are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information. Examples of machine-readable media include electronic circuitry, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio Frequency (RF) links, and the like. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Specific examples are set forth herein to illustrate the principles and embodiments of the present application, and the description of the examples above is only intended to assist in understanding the methods of the present application and their core ideas. The foregoing is merely a preferred embodiment of the present application, and it should be noted that, due to the limited text expressions, there is objectively no limit to the specific structure, and it will be apparent to those skilled in the art that numerous modifications, adaptations or variations can be made thereto and that the above-described features can be combined in a suitable manner without departing from the principles of the present application; such modifications, variations, or combinations, or the direct application of the concepts and aspects of the present application to other applications without modification, are intended to be within the scope of the present application.

Claims

1. A dual power isolation circuit, the dual power isolation circuit comprising:

the bypass isolation module comprises a second switch and a current limiting resistor connected with the second switch in series, and two ends of the second switch are respectively connected with a first power supply and a second power supply;

The logic control module is connected with the main path isolation module and the bypass isolation module and is used for controlling the second switch and the first switch to be turned on successively under the condition that the first power supply and the second power supply are electrified; and under the condition that the first power supply and the second power supply are powered down, the first switch is controlled to be disconnected.

2. The dual power isolation circuit of claim 1, wherein the main isolation module comprises a first control unit, a first switch drive unit, and at least one of a first current detection unit, a voltage detection unit, or a first temperature sampling unit;

3. The dual power isolation circuit of claim 2, wherein said first current detection unit comprises:

The first sampling resistor is connected in series with the first switch;

the first overcurrent detection device is connected with the first operational amplifier and is used for sending the overcurrent signal to the first control unit under the condition that the signal amplitude of the current signal meets an overcurrent threshold and the maintaining time length reaches a protection time length threshold.

4. The dual power isolation circuit of claim 2, wherein the voltage detection unit comprises:

and the second voltage detection device is connected with the second power supply and is used for acquiring the second power supply voltage of the second power supply and sending an overvoltage signal or an undervoltage signal to the first control unit under the condition that the second power supply voltage does not meet a second voltage range.

5. The dual power isolation circuit of claim 2, wherein the bypass isolation module comprises a second control unit, a second switch drive unit, and at least one of a second current detection unit or a second temperature sampling unit;

6. The dual power isolation circuit of claim 2, wherein said first switch comprises at least two pairs of MOSFETs in series, each pair of MOSFETs being connected in parallel with each other, a first pole of a body diode of one of each pair of MOSFETs being connected to a first pole of a body diode of the other pair of MOSFETs;

the first switch driving unit comprises a first gate driving unit and a second gate driving unit, wherein the first gate driving unit is used for driving a first MOSFET in each pair of MOSFETs, and the second gate driving unit is used for driving a second MOSFET in each pair of MOSFETs; the anode of the body diode of the first MOSFET is connected with the first power supply, and the anode of the body diode of the second MOSFET is connected with the second power supply;

7. The dual power isolation circuit of claim 6, wherein the first current detection unit is configured to detect a bi-directional current signal between the first power supply and the second power supply;

the first control unit is used for sending a turn-off signal to the second grid driving unit under the condition that the overcurrent signal, the overvoltage signal or the undervoltage signal of the first power supply or the undervoltage signal of the second power supply from the first power supply to the second power supply is received; and sending a turn-off signal to the first gate driving unit when the over-current signal from the second power supply to the first power supply, the over-voltage signal of the second power supply or the under-voltage signal of the first power supply is received.

8. The dual power isolation circuit of claim 5, wherein said logic control module comprises:

the power taking unit comprises a first diode and a second diode, wherein the anode of the first diode is connected with the first power supply, and the anode of the second diode is connected with the second power supply;

the main control unit is connected with the power management unit, the first current detection unit, the second current detection unit and the voltage detection unit, and is used for sending a conduction signal to the second switch under the condition that the power-on signal is received, and sending the conduction signal to the first switch under the condition that the voltage difference value between the first power supply and the second power supply is smaller than a differential pressure threshold value.

9. The dual power isolation circuit of claim 5, wherein the overcurrent threshold of the first current detection unit is greater than the overcurrent threshold of the second current detection unit, and wherein the protection duration threshold of the first current detection unit is less than the protection duration threshold of the second current detection unit.

10. A dual power isolation device comprising the dual power isolation circuit of any one of claims 1-9.