High-side switching circuit

Abstract

The application discloses a high-side switch circuit, and relates to the field of switch quantity, which comprises a current sampling and fault signal output unit, a fault driving control unit and a switch driving control unit.The current sampling and fault signal output unit is used for receiving a power supply voltage, collecting a load current, and delivering the power supply voltage to a switch unit; when the switch unit is turned on, a voltage is output; when the switch unit is turned off, no voltage is output; when the load current is abnormal, a fault signal is generated and sent to the fault driving control unit; the fault driving control unit is used for receiving the fault signal, generating a switch driving off signal, and sending the switch driving off signal to the switch driving control unit; the switch driving control unit is used for receiving the switch driving off signal, turning off the circuit based on the switch driving off signal, generating a switch unit off signal, and sending the switch unit off signal to the switch unit; and the switch unit receives the switch unit off signal and controls itself to be turned off based on the switch unit off signal.The application improves the safety of the load and the whole circuit.

Description

Technical Field

[0001] This application relates to the field of switching output circuit technology, and in particular to a high-side switching circuit. Background Technology

[0002] There are three common switching output methods in PLCs: relay output, transistor output, and thyristor output. Each of these three output methods has its own characteristics and corresponding applications. Among them, the transistor output method is particularly suitable for applications that require high-speed output to achieve fast / precise control. At the same time, transistors are semiconductor devices with no mechanical contacts and have a long service life.

[0003] Transistor outputs are further divided into two types: high-side (PNP) switching output and low-side (NPN) switching output. The output terminal of the high-side switching output is between the positive terminal of the power supply and the load, forming a "positive terminal of power supply -> transistor switch -> load -> negative terminal of power supply" loop, that is, the output terminal directly controls the conduction and disconnection between the positive terminal of the power supply and the load. The output terminal of the low-side switching output is between the negative terminal of the power supply and the load, forming a "positive terminal of power supply -> load -> transistor switch -> negative terminal of power supply" loop, that is, the output terminal directly controls the conduction and disconnection between the negative terminal of the power supply and the load.

[0004] For applications with high safety and reliable grounding requirements, high-side switch output circuits are often chosen. To achieve overcurrent / short-circuit protection in high-side switch circuits, fuses are commonly used. However, fuses have a slow response time and provide untimely protection. When a short-circuit fault occurs in the load, the transistors in the circuit are prone to instantaneous overload and damage, resulting in low safety. Summary of the Invention

[0005] The purpose of this application is to provide a high-side switching circuit to solve the problem described in the background art where the load or transistors in the circuit are easily damaged when an overcurrent or short circuit occurs, resulting in low safety.

[0006] To achieve the above objectives, this application provides a high-side switching circuit, comprising: The current sampling and fault signal output unit, the fault drive control unit, the switch drive control unit, and the switch unit are connected in sequence, and the current sampling and fault signal output unit is also connected to the switch unit. The current sampling and fault signal output unit is used to receive the power supply voltage supplied by the positive terminal of the power supply and to collect the load current, and then supply the power supply voltage to the switching unit; when the switching unit is in the on state, the voltage is output through the switching unit for the load to use; when the switching unit is in the off state, the switching unit has no voltage output. The current sampling and fault signal output unit is also used to collect the fault signal corresponding to the load current when the load current is abnormal, and send the fault signal to the fault drive control unit. The fault drive control unit is used to receive the fault signal, generate a switch drive disconnect signal based on the fault signal, and send the switch drive disconnect signal to the switch drive control unit. The switch drive disconnect signal is used to disconnect the switch drive control unit. The switch drive control unit is used to receive the switch drive disconnect signal, disconnect its own circuit based on the switch drive disconnect signal to generate a switch unit disconnect signal, and send the switch unit disconnect signal to the switch unit. The switching unit receives the switching unit disconnect signal and controls itself to disconnect based on the switching unit disconnect signal.

[0007] Optionally, the current sampling and fault signal output unit includes a power receiving terminal, a power output terminal, a fault signal output terminal, a sampling resistor, and a second transistor; the power receiving terminal is connected to the positive terminal of the power supply, the power output terminal is connected to the voltage receiving terminal of the switching unit, and the sampling resistor is connected between the power receiving terminal and the power output terminal; the emitter of the second transistor is connected to the power receiving terminal; the collector of the second transistor is connected to the fault signal output terminal; and the base of the second transistor is connected to the power output terminal.

[0008] Optionally, the current sampling and fault signal output unit is further provided with a first capacitor and a second resistor; the first capacitor is connected between the power receiving terminal and the base of the second transistor, and the second resistor is connected between the power output terminal and the base of the second transistor.

[0009] Optionally, the fault drive control unit includes a fault signal receiving terminal, a disconnect signal output terminal, a fourth transistor, a fifth transistor, a seventh transistor, a fifth resistor, a sixth resistor, a ninth resistor, and an eleventh resistor; The fault signal receiving terminal is connected to the fault signal output terminal. The sixth resistor is connected between the fault signal receiving terminal and the gate of the fifth transistor. The source of the fifth transistor is connected to the first ground terminal. The eleventh resistor is connected between the drain of the fifth transistor and the gate of the fourth transistor. The ninth resistor is connected between the gate of the fourth transistor and the source of the fourth transistor. The source of the fourth transistor is connected to the power receiving terminal. The fifth resistor is connected between the drain of the fourth transistor and the gate of the seventh transistor. The source of the seventh transistor is grounded. The drain of the seventh transistor is connected to the disconnect signal output terminal.

[0010] Optionally, the fault drive control unit further includes a second capacitor and an eighth resistor, wherein the second capacitor is connected between the fault signal receiving terminal and the first ground terminal, and the eighth resistor is connected between the fault signal receiving terminal and the first ground terminal; The fault drive control unit further includes a third capacitor and a tenth resistor. The third capacitor is connected between the drain of the fourth transistor and the first ground terminal, and the tenth resistor is connected between the drain of the fourth transistor and the first ground terminal.

[0011] Optionally, the switch drive control unit includes a disconnect signal receiving terminal, a switch signal receiving terminal, a control signal output terminal, and a sixth transistor. The disconnect signal receiving terminal is connected to the disconnect signal output terminal, the gate of the sixth transistor is connected to the disconnect signal receiving terminal, the gate of the sixth transistor is also connected to the switch signal receiving terminal, the source of the sixth transistor is connected to a second ground terminal, and the drain of the sixth transistor is connected to the control signal output terminal.

[0012] Optionally, the switch drive control unit further includes a twelfth resistor, a thirteenth resistor, and a fourth capacitor. The twelfth resistor is connected between the switch signal receiving terminal and the gate of the sixth transistor, the thirteenth resistor is connected between the gate of the sixth transistor and the second ground terminal, and the fourth capacitor is connected between the gate of the sixth transistor and the second ground terminal. The switch drive control unit further includes a second diode, the positive terminal of which is connected to the gate of the sixth transistor, and the negative terminal of which is connected to the switch signal receiving terminal.

[0013] Optionally, the switching unit includes a control signal receiving terminal, a voltage receiving terminal, a voltage output terminal, a first transistor, a third transistor, a third resistor, a fourth resistor, and a seventh resistor; the control signal receiving terminal is connected to the control signal output terminal, the voltage receiving terminal is connected to the power supply output terminal, and the voltage output terminal is used to connect to a load; the emitter of the first transistor is connected to the voltage receiving terminal, and the collector of the first transistor is connected to the voltage output terminal; the third resistor is connected between the voltage receiving terminal and the base of the first transistor; the emitter of the third transistor is connected to the base of the first transistor, and the collector of the third transistor is connected to the voltage output terminal; the fourth resistor is connected between the voltage receiving terminal and the base of the third transistor; and the seventh resistor is connected between the base of the third transistor and the control signal receiving terminal.

[0014] Optionally, the high-side switching circuit further includes a bidirectional transient voltage suppression diode, which is connected between the voltage output terminal and the second ground terminal.

[0015] Optionally, the high-side switching circuit further includes a microcontroller unit, the switching signal output terminal of which is connected to the switching signal receiving terminal of the switch drive control unit, for sending a switching signal to the switch drive control unit; The switch drive control unit is also used to receive the switch signal and control itself to turn on or off based on the switch signal, thereby generating a corresponding switch unit turn-on signal or switch unit turn-off signal and sending it to the switch unit.

[0016] According to the specific embodiments provided in this application, the following technical effects are disclosed: The high-side switching circuit provided in this embodiment is equipped with a current sampling and fault signal output unit. This unit can sample the load current and, when the load current is abnormal, send the corresponding fault signal to the fault drive control unit. After receiving the fault signal, the fault drive control unit generates a switch drive disconnect signal and sends it to the switch drive control unit. Upon receiving the switch drive disconnect signal, the switch drive control unit controls its own circuit to be in a disconnected state to generate a switch unit disconnect signal and sends it to the switch unit. Upon receiving the switch unit disconnect signal, the switch unit performs a disconnect operation to disconnect the power supply voltage output, thereby achieving the function of timely protection of the load and the entire high-side switching circuit. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a high-side switching circuit provided in an embodiment of this application; Figure 2 A circuit diagram of another high-side switching circuit provided in an embodiment of this application; Figure 3 A circuit diagram of another high-side switching circuit provided in an embodiment of this application.

[0019] In the diagram: Power receiver 1; Power output 2; Fault signal output 3; Fault signal receiver 4; Disconnect signal output 5; Disconnect signal receiver 6; Switch signal receiver 7; Control signal output 8; Control signal receiver 9; Voltage receiver 10; Voltage output 11; Switch signal output 12; Sampling resistor (first resistor) R1; Second resistor R2; Third resistor R3; Fourth resistor R4; Fifth resistor R5; Sixth resistor R6; Seventh resistor R7; Eighth resistor R8; Ninth resistor R9; Tenth resistor R10; Eleventh resistor R11; Twelfth resistor R12; Thirteenth resistor R13; First capacitor C1; Second capacitor C2; Third capacitor C3; Fourth capacitor C4; First transistor Q1; Second transistor Q2; Third transistor Q3; Fourth transistor Q4; Fifth transistor Q5; Sixth transistor Q6; Seventh transistor Q7; First diode D1; Second diode D2; First ground terminal 13; Second ground terminal 14. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the contents of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In one exemplary embodiment, see Figure 1 As shown, a high-side switching circuit is provided, which includes a current sampling and fault signal output unit, a fault drive control unit, a switch drive control unit and a switch unit connected in sequence, wherein the current sampling and fault signal output unit is also connected to the switch unit; The current sampling and fault signal output unit is used to receive the power supply voltage supplied by the positive terminal of the power supply and to collect the load current, and then supply the power supply voltage to the switching unit; when the switching unit is in the on state, the voltage is output through the switching unit for the load to use; when the switching unit is in the off state, the switching unit has no voltage output. The current sampling and fault signal output unit is also used to collect the fault signal corresponding to the load current when the load current is abnormal, and send the fault signal to the fault drive control unit. The fault drive control unit is used to receive the fault signal, generate a switch drive disconnect signal based on the fault signal, and send the switch drive disconnect signal to the switch drive control unit. The switch drive disconnect signal is used to disconnect the switch drive control unit. The switch drive control unit is used to receive the switch drive disconnect signal, disconnect its own circuit based on the switch drive disconnect signal to generate a switch unit disconnect signal, and send the switch unit disconnect signal to the switch unit. The switching unit receives the switching unit disconnect signal and controls itself to disconnect based on the switching unit disconnect signal.

[0023] The receiving end of the current sampling and fault signal output unit is connected to the positive terminal of the power supply to receive the power supply voltage output by the power supply.

[0024] Among them, abnormal load current refers to excessive load current, such as when the load current exceeds the preset current value, for example, when the load is short-circuited, or when the load current is too high due to other reasons. The preset current value can be the rated current of the load.

[0025] Unless otherwise specified, the “connection” mentioned in this application refers to an electrical signal connection achieved through a cable.

[0026] The high-side switching circuit provided in this embodiment is equipped with a current sampling and fault signal output unit. This unit can sample the load current and, when the load current is abnormal, send the corresponding fault signal to the fault drive control unit. After receiving the fault signal, the fault drive control unit generates a switch drive disconnect signal and sends it to the switch drive control unit. Upon receiving the switch drive disconnect signal, the switch drive control unit controls its own circuit to be in a disconnected state to generate a switch unit disconnect signal and sends it to the switch unit. Upon receiving the switch unit disconnect signal, the switch unit performs a disconnect operation to disconnect the power supply voltage output. This achieves the effect of timely protection of the load and the entire high-side switching circuit, improving the safety of the load and the entire circuit.

[0027] Optionally, see Figure 1 and Figure 2In another exemplary embodiment of this application, the current sampling and fault signal output unit is provided with a power receiving terminal 1, a power output terminal 2, a fault signal output terminal 3, a sampling resistor R1, and a second transistor Q2; the power receiving terminal 1 is connected to the positive terminal of the power supply, the power output terminal 2 is connected to the voltage receiving terminal 10 of the switching unit, and the sampling resistor R1 is connected between the power receiving terminal 1 and the power output terminal 2; the emitter of the second transistor Q2 is connected to the power receiving terminal 1; the collector of the second transistor Q2 is connected to the fault signal output terminal 3; and the base of the second transistor Q2 is connected to the power output terminal 2.

[0028] The sampling resistor R1, also referred to as the first resistor, is used to collect the load current. The value of the sampling resistor R1 can be selected according to the actual circuit.

[0029] The second transistor, Q2, is a PNP transistor.

[0030] During operation, the power receiving terminal 1 receives the voltage output from the positive terminal of the power supply and sends it to the sampling resistor R1, which then sends it to the power output terminal 2. At the same time, the sampling resistor R1 collects the load current. When the load experiences an overcurrent or short circuit fault, the current flowing through the sampling resistor R1 increases abnormally, and the voltage across the sampling resistor R1 rises. For example, when the voltage is greater than the turn-on voltage of the second transistor Q2, the second transistor Q2 will be turned on, and a voltage signal will be output through the collector of the second transistor Q2. This voltage signal is recorded as a fault signal and sent to the fault signal output terminal 3.

[0031] Further, see Figure 3 The current sampling and fault signal output unit is further provided with a first capacitor C1 and a second resistor R2; the first capacitor C1 is connected between the power receiving terminal 1 and the base of the second transistor Q2, and the second resistor R2 is connected between the power output terminal 2 and the base of the second transistor Q2.

[0032] The first capacitor C1 and the second resistor R2 form a low-pass filter circuit, which filters the voltage signal across the sampling resistor R1 to achieve anti-interference and prevent the second transistor Q2 from being mistakenly turned on when the sampling current fluctuates.

[0033] When the sampling current is too large due to a load short circuit or other reasons, the second transistor Q2 will be turned on and generate a fault signal when the voltage across the sampling resistor R1 reaches the turn-on voltage of the second transistor Q2.

[0034] Optionally, see Figure 1 and Figure 2In another exemplary embodiment of this application, the fault drive control unit includes a fault signal receiving terminal 4, a disconnect signal output terminal 5, a fourth transistor Q4, a fifth transistor Q5, a seventh transistor Q7, a fifth resistor R5, a sixth resistor R6, a ninth resistor R9, and an eleventh resistor R11. The fault signal receiving terminal 4 is connected to the fault signal output terminal 3. The sixth resistor R6 is connected between the fault signal receiving terminal 4 and the gate of the fifth transistor Q5. The source of the fifth transistor Q5 is connected to the first ground terminal 13. The eleventh resistor R11 is connected between the drain of the fifth transistor Q5 and the gate of the fourth transistor Q4. The ninth resistor R9 is connected between the gate of the fourth transistor Q4 and the source of the fourth transistor Q4. The source of the fourth transistor Q4 is connected to the power receiving terminal 1. The fifth resistor R5 is connected between the drain of the fourth transistor Q4 and the gate of the seventh transistor Q7. The source of the seventh transistor Q7 is grounded. The drain of the seventh transistor Q7 is connected to the disconnect signal output terminal 5.

[0035] Among them, the fourth transistor Q4, the fifth transistor Q5, and the seventh transistor Q7 are MOSFETs. The resistance values ​​of the fifth resistor R5, the sixth resistor R6, the ninth resistor R9, and the eleventh resistor R11 are selected according to actual needs.

[0036] The fault signal is a high-voltage signal that can turn on the fifth transistor Q5.

[0037] During operation, when the fault signal receiver 4 receives the fault signal, i.e., the voltage signal, it passes through the sixth resistor R6, at which point the fifth transistor Q5 is turned on. After the fifth transistor Q5 is turned on, the voltage of the eleventh resistor R11 is pulled low. At this time, the power supply receiver 1, the ninth resistor R9, the eleventh resistor R11, the fifth transistor Q5, and the first ground terminal 13 form a circuit. At this time, the fourth transistor Q4 is turned on. After the fourth transistor Q4 is turned on, it transmits the power supply voltage to the fifth resistor R5, and finally to the gate of the seventh transistor Q7, causing Q7 to turn on. After the seventh transistor Q7 is turned on, the current of the seventh transistor Q7 flows from the drain to the source. Since the source is directly grounded, the final result is that the drain voltage of the seventh transistor Q7 is pulled low to ground potential, generating a low voltage signal, i.e., a disconnect signal, which is sent to the disconnect signal output terminal 5 to force disconnect the switch drive control unit.

[0038] Further, see Figure 3 The fault drive control unit further includes a second capacitor C2 and an eighth resistor R8. The second capacitor C2 is connected between the fault signal receiving terminal 4 and the first ground terminal 13, and the eighth resistor R8 is connected between the fault signal receiving terminal 4 and the first ground terminal 13.

[0039] The second capacitor C2 and the eighth resistor R8 form a fault signal delay circuit. By charging the second capacitor C2, the conduction time of the fifth transistor Q5 and the fourth transistor Q4 is maintained, thereby extending the duration of the fault signal. The conduction of the fourth transistor Q4 will cause the third capacitor C3 to charge rapidly, and the third capacitor C3 will maintain the conduction time of the seventh transistor Q7. Thus, the above process ensures that the fifth transistor Q5, the fourth transistor Q4, and the seventh transistor Q7 can conduct smoothly.

[0040] Further, see Figure 3 The fault drive control unit further includes a third capacitor C3 and a tenth resistor R10. The third capacitor C3 is connected between the drain of the fourth transistor Q4 and the first ground terminal 13, and the tenth resistor R10 is connected between the drain of the fourth transistor Q4 and the first ground terminal 13.

[0041] The third capacitor C3 and the tenth resistor R10 form a fault signal delay circuit. After the third capacitor C3 is charged, it will maintain the conduction time of the seventh transistor Q7 to extend the maintenance time of the fault signal and ensure that the subsequent seventh transistor Q7 can be turned on smoothly.

[0042] By maintaining a certain delay in the fault signal, the fourth transistor Q4 is ensured to have enough conduction time to fully charge the third capacitor C3, thereby achieving the turn-off delay effect of the entire circuit and reducing the heat generation of the power transistor.

[0043] Furthermore, if the seventh transistor Q7 remains in the on state, the gate of the sixth transistor Q6 remains in the low level state, and the microcontroller unit will not be able to turn the sixth transistor Q6 on again; the microcontroller unit can only control the sixth transistor Q6 to turn on when the seventh transistor Q7 is turned off again.

[0044] Optionally, see Figure 1 and Figure 2 In another exemplary embodiment of this application, the switch drive control unit includes a disconnect signal receiving terminal 6, a switch signal receiving terminal 7, a control signal output terminal 8, and a sixth transistor Q6. The disconnect signal receiving terminal 6 is connected to the disconnect signal output terminal 5. The gate of the sixth transistor Q6 is connected to the disconnect signal receiving terminal 6. The gate of the sixth transistor Q6 is also connected to the switch signal receiving terminal 7. The source of the sixth transistor Q6 is connected to the second ground terminal 14. The drain of the sixth transistor Q6 is connected to the control signal output terminal 8.

[0045] Among them, the sixth transistor Q6 is a MOSFET.

[0046] During operation, the switch signal is received through the switch signal receiver 7. When the received switch signal is a high-level turn-on signal, the gate of the sixth transistor Q6 is pulled to a high level, and the sixth transistor Q6 is turned on. Then, both the drain and source of the sixth transistor Q6 are grounded and are at a low level. The drain sends a switch unit turn-on signal to the control signal output terminal 8, so that the control signal output terminal 8 sends the switch unit turn-on signal to the switch unit. When the received switch signal is a low-level turn-off signal, the gate of the sixth transistor Q6 is at a low level, and the sixth transistor Q6 is in a turn-off state. Then, the drain is at a high level, and the drain sends a switch unit turn-off signal to the control signal output terminal 8. The control signal output terminal 8 outputs the switch unit turn-off signal, so that the control signal output terminal 8 sends the switch unit turn-off signal to the switch unit.

[0047] In addition, when the disconnect signal receiver 6 receives the switch drive disconnect signal, since the switch drive disconnect signal is a low-level signal pulled down by the first ground terminal 13, the gate of the sixth transistor Q6 can be forcibly pulled low. Therefore, even if the microcontroller unit sends a high-level turn-on signal, the sixth transistor Q6 cannot be turned on.

[0048] Optionally, see Figure 3 The switch drive control unit further includes a twelfth resistor R12, a thirteenth resistor R13, and a fourth capacitor C4. The twelfth resistor R12 is connected between the switch signal receiving terminal 7 and the gate of the sixth transistor Q6. The thirteenth resistor R13 is connected between the gate of the sixth transistor Q6 and the second ground terminal 14. The fourth capacitor C4 is connected between the gate of the sixth transistor Q6 and the second ground terminal 14.

[0049] The twelfth resistor R12, the thirteenth resistor R13, and the fourth capacitor C4 are used to delay the turn-on of the sixth transistor Q6, while the second diode D2 is used to accelerate the turn-off of the sixth transistor Q6. By making the sixth transistor Q6 "delay the turn-on and accelerate the turn-off", the output pulse width and the pulse width issued by the microcontroller unit can be kept as consistent as possible.

[0050] Optionally, see Figure 3 The switch drive control unit further includes a second diode D2, the positive terminal of which is connected to the gate of the sixth transistor Q6, and the negative terminal of which is connected to the switch signal receiving terminal 7.

[0051] Among them, the second diode D2 is a common diode.

[0052] When the sixth transistor Q6 is turned off, the current in the gate of the sixth transistor Q6 can be released through the second diode D2, which can speed up the turn-off speed of the sixth transistor Q6.

[0053] It should be noted that when the overcurrent or short-circuit fault is cleared, the current sampled by the sampling resistor R1 decreases, and the voltage across the sampling resistor R1 decreases, causing the second transistor Q2 to turn off. This sends a low-level signal to the fault drive control unit, causing all transistors in the fault drive control unit to turn off. The gate of the sixth transistor Q6 is no longer forcibly pulled low. At this time, the conduction or disconnection of the sixth transistor Q6 is again controlled by the received switching signal, restoring normal operation. Therefore, the circuit provided in this application can not only automatically disconnect the switching unit to achieve the protection function, but also automatically restore normal operation.

[0054] In addition, due to limitations in the design of the internal high-voltage drive circuit, the switching frequency of existing high-side switching circuit chips is often not very high, so they generally do not support the output of high-speed pulses, such as the 200kHz pulse commonly used in industrial control.

[0055] In addition, the twelfth resistor R12, the thirteenth resistor R13, and the fourth capacitor C4 of the switch drive control unit can adjust the pulse duty cycle, thereby ensuring that the duty cycle of the voltage output terminal 11 is consistent with the switch signal. The second diode D2 can also accelerate the disconnection of the sixth transistor Q6. Thus, the twelfth resistor R12, the thirteenth resistor R13, the fourth capacitor C4, and the second diode D2 work together to adjust the output performance of the entire circuit, thereby meeting the requirements of high-speed pulse output and satisfying the 200kHz pulse requirements commonly used in industrial control.

[0056] R12 / R13 / C4 can delay the turn-on of Q6, and D2 can accelerate the turn-off of Q6. This allows Q6 to delay its turn-on and accelerate its turn-off, thereby adjusting the output pulse width of the entire circuit to be close to that of the microcontroller unit, thus meeting the requirements of high-speed pulse output.

[0057] Optionally, see Figure 1 and Figure 2In another exemplary embodiment of this application, the switching unit includes a control signal receiving terminal 9, a voltage receiving terminal 10, a voltage output terminal 11, a first transistor Q1, a third transistor Q3, a third resistor R3, a fourth resistor R4, and a seventh resistor R7; the control signal receiving terminal 9 is connected to the control signal output terminal 8, the voltage receiving terminal 10 is connected to the power output terminal 2, and the voltage output terminal 11 is used to connect to a load; the emitter of the first transistor Q1 is connected to the voltage receiving terminal 10, and the collector of the first transistor Q1 is connected to the voltage output terminal 11; the third resistor R3 is connected between the voltage receiving terminal 10 and the base of the first transistor Q1; the emitter of the third transistor Q3 is connected to the base of the first transistor Q1, and the collector of the third transistor Q3 is connected to the voltage output terminal 11; the fourth resistor R4 is connected between the voltage receiving terminal 10 and the base of the third transistor Q3; and the seventh resistor R7 is connected between the base of the third transistor Q3 and the control signal receiving terminal 9.

[0058] Among them, the first transistor Q1 and the third transistor Q3 are PNP transistors, and the third transistor Q3 is a small signal transistor.

[0059] During operation, when the control signal receiver 9 receives a low-level switch unit turn-on signal, the voltage across the seventh resistor R7 is pulled low, and the third transistor Q3 is turned on. After the third transistor Q3 is turned on, the voltage at the base of the first transistor Q1 is pulled low, and the first transistor Q1 is turned on. At this time, voltage is supplied from the voltage receiver 10 to the voltage output terminal 11 to power the load. When the control signal receiver 9 receives a high-level switch unit turn-off signal, the voltage across the seventh resistor R7 is pulled high, and the third transistor Q3 is turned off. After the third transistor Q3 is turned off, the voltage at the base of the first transistor Q1 is pulled high, and the first transistor Q1 is turned off. At this time, there is no voltage output from the voltage output terminal 11.

[0060] Optionally, see Figure 1 and Figure 2 In another exemplary embodiment of this application, the high-side switching circuit further includes a first diode D1, which is a bidirectional transient voltage suppression diode connected between the voltage output terminal 11 and the second ground terminal 14.

[0061] Bidirectional transient voltage suppressor diodes are used to clamp and protect against transient overvoltages in both positive and negative directions.

[0062] Optionally, see Figure 1 and Figure 2In another exemplary embodiment of this application, the high-side switch circuit further includes a microcontroller unit, wherein the switch signal output terminal 12 of the microcontroller unit is connected to the switch signal receiving terminal 7 of the switch drive control unit, and is used to send a switch signal to the switch drive control unit; The switch drive control unit is also used to receive the switch signal and control itself to turn on or off based on the switch signal, thereby generating a corresponding switch unit turn-on signal or switch unit turn-off signal and sending it to the switch unit.

[0063] In daily operation, the microcontroller unit sends a switching signal to the switch drive control unit to control the switch unit to turn on or off, thereby enabling the power supply to or from the load.

[0064] Furthermore, the microcontroller unit can be a microcontroller, which can directly drive the high-side switching circuit through the microcontroller's I / O port without the need for an additional boost circuit or level conversion unit.

[0065] Optionally, see Figure 1 and Figure 2 In another exemplary embodiment of this application, the high-side switch circuit further includes an indicator unit, the signal receiving of which is connected to the fault signal output terminal 3, for receiving the fault signal and generating a fault reminder based on the fault signal.

[0066] The fault alerts include voice alerts, text alerts, or alerts by illuminating indicator lights.

[0067] This fault signal is also an overcurrent or short-circuit feedback signal of the load. It is output by the indicator unit to facilitate timely detection of the fault and timely execution of fault diagnosis operations.

[0068] Currently, most intelligent high-side switch circuits with protection functions on the market adopt integrated chip solutions. However, there are few manufacturers that design such integrated chip solutions, resulting in a limited range of model choices and higher costs. This application uses simple components and designs a simple circuit structure to reduce costs.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A high-side switching circuit, characterized in that, include: The current sampling and fault signal output unit, the fault drive control unit, the switch drive control unit, and the switch unit are connected in sequence, and the current sampling and fault signal output unit is also connected to the switch unit. The current sampling and fault signal output unit is used to receive the power supply voltage supplied by the positive terminal of the power supply and to collect the load current, and then supply the power supply voltage to the switching unit; when the switching unit is in the on state, the voltage is output through the switching unit for the load to use; when the switching unit is in the off state, the switching unit has no voltage output. The current sampling and fault signal output unit is also used to collect the fault signal corresponding to the load current when the load current is abnormal, and send the fault signal to the fault drive control unit. The fault drive control unit is used to receive the fault signal, generate a switch drive disconnect signal based on the fault signal, and send the switch drive disconnect signal to the switch drive control unit. The switch drive disconnect signal is used to disconnect the switch drive control unit. The switch drive control unit is used to receive the switch drive disconnect signal, disconnect its own circuit based on the switch drive disconnect signal to generate a switch unit disconnect signal, and send the switch unit disconnect signal to the switch unit. The switching unit receives the switching unit disconnect signal and controls itself to disconnect based on the switching unit disconnect signal.

2. The high-side switching circuit according to claim 1, characterized in that, The current sampling and fault signal output unit includes a power receiving terminal, a power output terminal, a fault signal output terminal, a sampling resistor, and a second transistor. The power receiving terminal is connected to the positive terminal of the power supply, the power output terminal is connected to the voltage receiving terminal of the switching unit, and the sampling resistor is connected between the power receiving terminal and the power output terminal. The emitter of the second transistor is connected to the power receiving terminal, the collector of the second transistor is connected to the fault signal output terminal, and the base of the second transistor is connected to the power output terminal.

3. The high-side switching circuit according to claim 2, characterized in that, The current sampling and fault signal output unit is further provided with a first capacitor and a second resistor; the first capacitor is connected between the power receiving terminal and the base of the second transistor, and the second resistor is connected between the power output terminal and the base of the second transistor.

4. The high-side switching circuit according to claim 1, characterized in that, The fault drive control unit includes a fault signal receiving terminal, a disconnect signal output terminal, a fourth transistor, a fifth transistor, a seventh transistor, a fifth resistor, a sixth resistor, a ninth resistor, and an eleventh resistor. The fault signal receiving terminal is connected to the fault signal output terminal. The sixth resistor is connected between the fault signal receiving terminal and the gate of the fifth transistor. The source of the fifth transistor is connected to the first ground terminal. The eleventh resistor is connected between the drain of the fifth transistor and the gate of the fourth transistor. The ninth resistor is connected between the gate of the fourth transistor and the source of the fourth transistor. The source of the fourth transistor is connected to the power receiving terminal. The fifth resistor is connected between the drain of the fourth transistor and the gate of the seventh transistor. The source of the seventh transistor is grounded. The drain of the seventh transistor is connected to the disconnect signal output terminal.

5. The high-side switching circuit according to claim 4, characterized in that, The fault drive control unit further includes a second capacitor and an eighth resistor. The second capacitor is connected between the fault signal receiving terminal and the first ground terminal, and the eighth resistor is connected between the fault signal receiving terminal and the first ground terminal. The fault drive control unit further includes a third capacitor and a tenth resistor. The third capacitor is connected between the drain of the fourth transistor and the first ground terminal, and the tenth resistor is connected between the drain of the fourth transistor and the first ground terminal.

6. The high-side switching circuit according to claim 1, characterized in that, The switch drive control unit includes a disconnect signal receiving terminal, a switch signal receiving terminal, a control signal output terminal, and a sixth transistor. The disconnect signal receiving terminal is connected to the disconnect signal output terminal. The gate of the sixth transistor is connected to the disconnect signal receiving terminal and is also connected to the switch signal receiving terminal. The source of the sixth transistor is connected to a second ground terminal, and the drain of the sixth transistor is connected to the control signal output terminal.

7. The high-side switching circuit according to claim 6, characterized in that, The switch drive control unit further includes a twelfth resistor, a thirteenth resistor, and a fourth capacitor. The twelfth resistor is connected between the switch signal receiving terminal and the gate of the sixth transistor. The thirteenth resistor is connected between the gate of the sixth transistor and the second ground terminal. The fourth capacitor is connected between the gate of the sixth transistor and the second ground terminal. The switch drive control unit further includes a second diode, the positive terminal of which is connected to the gate of the sixth transistor, and the negative terminal of which is connected to the switch signal receiving terminal.

8. The high-side switching circuit according to claim 1, characterized in that, The switching unit includes a control signal receiving terminal, a voltage receiving terminal, a voltage output terminal, a first transistor, a third transistor, a third resistor, a fourth resistor, and a seventh resistor. The control signal receiving terminal is connected to the control signal output terminal, the voltage receiving terminal is connected to the power output terminal, and the voltage output terminal is used to connect to a load. The emitter of the first transistor is connected to the voltage receiving terminal, and the collector of the first transistor is connected to the voltage output terminal. The third resistor is connected between the voltage receiving terminal and the base of the first transistor. The emitter of the third transistor is connected to the base of the first transistor, and the collector of the third transistor is connected to the voltage output terminal. The fourth resistor is connected between the voltage receiving terminal and the base of the third transistor. The seventh resistor is connected between the base of the third transistor and the control signal receiving terminal.

9. The high-side switching circuit according to claim 1, characterized in that, The high-side switching circuit also includes a bidirectional transient voltage suppression diode, which is connected between the voltage output terminal and the second ground terminal.

10. The high-side switching circuit according to claim 1, characterized in that, The high-side switching circuit also includes a microcontroller unit, the switching signal output terminal of which is connected to the switching signal receiving terminal of the switch drive control unit, for sending a switching signal to the switch drive control unit; The switch drive control unit is also used to receive the switch signal and control itself to turn on or off based on the switch signal, thereby generating a corresponding switch unit turn-on signal or switch unit turn-off signal and sending it to the switch unit.

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