High-drive circuit, LED high-drive hardware turn-off circuit and calling system
By introducing a combination of transistors and voltage divider resistors into the high-drive circuit, a fast hardware shutdown is achieved, solving the problem of overcurrent burnout caused by MCU detection delay and ensuring circuit safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2026-04-07
AI Technical Summary
In the case of a short power supply abnormality, the existing high-drive circuit has a time delay in the MCU's detection, judgment and shutdown actions, which leads to a significant increase in current and poses a risk of overcurrent burnout.
Introducing a combination of a first transistor, a second transistor, and a third transistor, along with voltage divider resistors, into the high-drive circuit enables rapid hardware shutdown, reducing shutdown time and preventing circuit damage.
It achieves rapid hardware shutdown before MCU detection, avoiding overcurrent damage to circuit components, reducing shutdown time, and lowering the risk of overcurrent burnout.
Smart Images
Figure CN224097699U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to circuit protection technical field, concretely relates to a high drive circuit, LED high drive's hardware shutdown circuit and calling system. BACKGROUND
[0002] In the traditional circuit control, usually in the low potential end (ground terminal) of the load switch control. And high drive circuit is contrary, is in the high potential end of the power supply switch operation, namely the output end of external power supply through high drive circuit for load power supply.
[0003] In the prior art, the high drive circuit includes two diodes and corresponding voltage dividing resistors, the circuit state is detected by a control module MCU (microcontroller unit, Microcontroller Unit), and the high drive circuit is turned on and turned off according to the circuit state, thereby controlling the on-off of the high drive circuit, and realizing the control of the load power supply.
[0004] However, when the short power supply anomaly occurs, the detection, judgment and shutdown of the MCU need a certain time, and the current in the whole circuit increases greatly in this period of time, and only the overcurrent protection of the external power supply can protect the whole circuit to a certain extent, and there is a certain degree of overcurrent burning risk. INVENTION CONTENTS
[0005] Therefore, the utility model provides a high drive circuit, LED high drive's hardware shutdown circuit and calling system to solve the problem of time delay of high drive circuit shutdown through MCU.
[0006] In a first aspect, the utility model provides a high drive circuit, including: first triode, second triode, third triode and preset quantity's voltage dividing resistor, wherein, the base of first triode and control module's control port and the collector of third triode are connected, and the collector of first triode and the base of second triode are connected;The emitter of second triode is connected with external power supply, the collector of second triode is connected with external load, is connected with the detection port of control module through first voltage dividing resistor, is connected with ground and the base of third triode through second voltage dividing resistor;The emitter of first triode, the emitter of third triode, first voltage dividing resistor and second voltage dividing resistor are connected with ground respectively.
[0007] The high drive circuit provided by the utility model, through deploying the first triode and the second triode between the control port of the control module and the external power supply, deploying the third triode between the first triode and the second triode, connecting between the detection port of the control module and the second triode and between the second triode and the third triode through the voltage dividing resistor, connecting the first triode, the second triode and the voltage dividing resistor with the grounding point, can realize the fast hardware shutdown in the high drive circuit before the MCU performs the shutdown control on the high drive circuit, reduce the shutdown time and avoid damaging the device in the circuit due to overcurrent.
[0008] In an alternative embodiment, the first voltage dividing resistor comprises a first resistor and a second resistor, the collector of the second triode is connected with the first end of the first resistor; the second end of the first resistor and the first end of the second resistor are connected with the detection port of the control module, and the second end of the second resistor is connected with the grounding point; the collector of the first triode is connected with the base of the second triode through a third resistor.
[0009] The utility model discloses a method for connecting the detection port of MCU between the two resistors between the second triode and the grounding point, can realize the ADC collection of MCU to the circuit through voltage division, thereby judging the state of the whole circuit. Further, the resistance between the first triode and the second triode can turn on the first triode and the second triode when the MCU detects normal operation and outputs high voltage, and can turn off the first triode and the second triode when the MCU detects short circuit and outputs low voltage, realize the on-off control of the high drive circuit, thereby realizing the control of the load power supply and avoiding damaging the circuit.
[0010] In an alternative embodiment, the second voltage dividing resistor comprises a fourth resistor and a fifth resistor, the collector of the second triode is connected with the first end of the fourth resistor; the second end of the fourth resistor and the first end of the fifth resistor are connected with the base of the third triode, and the second end of the fifth resistor is connected with the grounding point.
[0011] The utility model discloses a method for connecting the base of the third triode between the two resistors between the second triode and the grounding point, can directly turn on the third triode through voltage division when the voltage at the load interface becomes short power supply voltage, and further turn off the first triode and the second triode in succession due to the emitter of the third triode being grounded and the collector being connected with the base of the first triode, thereby realizing the hardware level shutdown.
[0012] In an alternative embodiment, the first triode and the third triode are NPN type triodes, and the second triode is a PNP type triode.
[0013] The utility model discloses that according to the circuit requirement, the triode of different models is arranged, can guarantee the load drive function and electrical isolation function of high drive circuit, so that the load can work normally.
[0014] In a second aspect, the utility model provides a kind of LED high drive's hardware shutdown circuit, comprising: external power supply, control module, LED load and the high drive circuit of above-mentioned first aspect or any of its corresponding implementation ways;External power supply is connected with the emitter of second triode in high drive circuit;The control port of control module is connected with the base of first diode in high drive circuit, and the detection port of control module is connected with first voltage dividing resistor in high drive circuit;LED load is connected with the collector of second triode.
[0015] The LED high drive's hardware shutdown circuit provided by the utility model, by external power supply provides power supply, under the detection and control of control module, by high drive circuit driving LED load to work when normal, short circuit is realized by high drive circuit internal hardware shutdown, and then by control module carries out logic shutdown, can reduce shutdown time, avoid the damage of device in circuit due to overcurrent.
[0016] In an alternative embodiment, the external power supply includes: a battery for providing external power supply of a first voltage; a voltage conversion module, the input end is connected with the battery, and the output end is connected with the emitter of the second triode, for converting the external power supply of the first voltage into a second voltage.
[0017] In an alternative embodiment, the voltage conversion module is a low-dropout linear regulator or a DC-DC converter.
[0018] In an alternative embodiment, the first voltage is 12V or 24V, and the second voltage is 5V.
[0019] The utility model can supply power according to the working condition of high drive circuit by voltage conversion, so as to drive LED load by high drive circuit to work, provide stable current for LED lamp, and ensure its brightness and service life.
[0020] In an alternative embodiment, the hardware shutdown circuit further includes: an external load connected with the output end of the voltage conversion module.
[0021] The utility model can supply power for different loads by being directly connected with external power supply and being connected with high drive circuit.
[0022] In a third aspect, the utility model further provides a calling system, comprising: the LED high drive's hardware shutdown circuit of the second aspect or any of its corresponding implementation ways.
[0023] Because the calling system includes the LED high drive's hardware shutdown circuit, it has the same effect as the LED high drive's hardware shutdown circuit, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0025] Figure 1 A schematic diagram of a conventional high drive circuit and a corresponding hardware shutdown circuit of LED high drive.
[0026] Figure 2 A schematic diagram of a conventional high drive circuit and a corresponding hardware shutdown circuit of LED high drive.
[0027] Explanation of reference signs:
[0028] Q1-first triode; Q2-second triode; Q3-third triode; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor. Specific embodiments
[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0030] The present application is applicable to the scene of driving load to work through high drive circuit, taking LED as an example. As shown in Figure 1 The principle of driving LED load to work by conventional high drive circuit is as follows:
[0031] ①The vehicle storage battery voltage 12V / 24V is input as input voltage to LDO (Low Dropout Regulator, low dropout regulator) or DCDC (DC-to-DC Converter, DC-to-DC converter), and after voltage reduction, VCC_5V is output, VCC_5V is used for power supply of LED high drive circuit, and also for power supply of other electric appliances;
[0032] ②MCU's GPIO1 (General Purpose Input / Output, GPIO1 is a general port of MCU) is used to control the on-off of the high drive circuit, when GPIO1 outputs high voltage, the transistors Q1 and Q2 are successively turned on, VCC_5V supplies power for the LED through Q2, when GPIO1 outputs low voltage, the transistors Q1 and Q2 are turned off, and the high drive is in the off state;
[0033] ③The voltage at the LED interface is divided by the voltage dividing resistors R1 and R2, and then collected by the ADC1 port of the MCU, and the voltage at the LED interface is calculated after the MCU collects the data, and the state (normal working, short circuit, short power supply, short ground) of the entire circuit is judged;
[0034] ④Once the short power supply occurs, the MCU detects it and immediately controls GPIO1 to output low voltage to disconnect the entire high drive circuit.
[0035] However, after the short power supply anomaly occurs, the series of actions of the MCU's ADC detection, judgment and pulling down GPIO1 takes a certain time, generally about 250ms, and during this period, the current in the entire circuit increases greatly, and only the overcurrent protection of the LDO / DCDC can protect the entire circuit to a certain extent, and there is a certain risk of overcurrent burning. Moreover, during this period, VCC_5V will be raised to the short power supply voltage, which may cause other power consumption places of this power supply voltage to malfunction or even be damaged, and there is a risk of overvoltage burning.
[0036] Therefore, the utility information provides a high drive circuit, a hardware shutdown circuit of an LED high drive and a calling system, and the embodiments of the utility model are described below. Figure 2 , the embodiments of the utility model are described below.
[0037] According to the embodiments of the utility model, on the one hand, a high drive circuit is provided, which comprises: a first transistor, a second transistor, a third transistor and a preset number of voltage dividing resistors, wherein the base of the first transistor is connected with the control port of the control module and the collector of the third transistor, and the collector of the first transistor is connected with the base of the second transistor; the emitter of the second transistor is connected with an external power supply, the collector of the second transistor is connected with an external load, connected with the detection port of the control module through the first voltage dividing resistor, and connected with the ground and the base of the third transistor through the second voltage dividing resistor; the emitter of the first transistor, the emitter of the third transistor, the first voltage dividing resistor and the second voltage dividing resistor are connected with the ground respectively.
[0038] Specifically, in the embodiments of the utility model, as shown in Figure 2 the first transistor Q1, the second transistor Q2, the first resistor R1, the second resistor R2 and the third resistor R3 are connected withFigure 1 The third transistor Q3, the fourth resistor R4 and the fifth resistor R5 are added on the basis of the same conventional high drive circuit. The first resistor R1 and the second resistor R2 correspond to the first voltage divider, the collector of the second transistor Q2 is connected with the first end of the first resistor R1; the second end of the first resistor R1 and the first end of the second resistor R2 are connected with the detection port ADC1 of the control module MCU, the second end of the second resistor R2 is connected with the ground point GND, and the collector of the first transistor Q1 is connected with the base of the second transistor Q2 through the third resistor R3. The fourth resistor R4 and the fifth resistor R5 correspond to the second voltage divider, the collector of the second transistor Q2 is connected with the first end of the fourth resistor R4; the second end of the fourth resistor R4 and the first end of the fifth resistor R5 are connected with the base of the third transistor Q3, the second end of the fifth resistor R5 is connected with the ground point GND.
[0039] In some optional embodiments, as shown in Figure 2 The first transistor Q1 and the third transistor Q3 are NPN transistors, and the second transistor Q2 is a PNP transistor. The NPN transistor and the PNP transistor are both semiconductor devices composed of three regions (emitter region, base region and collector region) and two PN junctions (emitter junction and collector junction). The NPN transistor is composed of two N-type semiconductors and a P-type semiconductor in the middle, and the carrier is mainly electron. When working, the emitter region injects electrons into the base region, the electrons diffuse in the base region and are collected by the collector region to form the collector current. When normally working, the collector (C) is connected with the positive electrode of the power supply, the emitter (E) is connected with the negative electrode of the power supply, and the base (B) is positively biased relative to the emitter, that is, V B >V E The current flows from the collector to the emitter, and the base current controls the size of the collector current. When the base has a suitable current input, a larger current will flow from the collector to the emitter; the PNP transistor is composed of two P-type semiconductors and an N-type semiconductor in the middle, and the carrier is mainly hole. The emitter region injects holes into the base region, the holes diffuse in the base region and are collected by the collector region to form the collector current. When working, the collector is connected with the negative electrode of the power supply, the emitter is connected with the positive electrode of the power supply, and the base is reversely biased relative to the emitter, that is, V B <V E The current flows from the emitter to the collector, and the base current also controls the collector current. The change of the base current will cause the corresponding change of the current from the emitter to the collector.
[0040] The high drive circuit provided by the utility model, through deploying the first triode and the second triode between the control port of the control module and the external power supply, deploying the third triode between the first triode and the second triode, connecting between the detection port of the control module and the second triode, and between the second triode and the third triode through the voltage dividing resistor, connecting the first triode, the second triode and the voltage dividing resistor with the grounding point, the fast hardware shutdown in the high drive circuit can be realized before the MCU performs the shutdown control on the high drive circuit, the shutdown time is reduced, and the damage of the device in the circuit due to the overcurrent is avoided.
[0041] According to the embodiment of the utility model, on the other hand, a kind of hardware shutdown circuit of LED high drive is further provided, comprising: external power supply, control module, LED load and Figure 2 High drive circuit shown in the figure;External power supply is connected with the emitter of the second triode in high drive circuit;The control port of control module is connected with the base of the first diode in high drive circuit, and the detection port of control module is connected with the first voltage dividing resistor in high drive circuit;LED load is connected with the collector of the second triode.
[0042] Specifically, in the embodiment of the utility model, external power supply includes: battery, for providing the first voltage of external power supply;Voltage conversion module, input end is connected with battery, output end is connected with the emitter of the second triode, for converting the first voltage of external power supply into second voltage. As Figure 2As shown, the voltage conversion module is a low dropout linear regulator or a DC-DC converter. The low dropout linear regulator (LDO) works on the principle of linear voltage regulation, adjusting the output voltage by adjusting the conduction of an internal power transistor (usually a transistor or MOSFET), and the difference between the input voltage and the output voltage is consumed by the power transistor in the form of heat. For example, when the input voltage is higher than the output voltage, the LDO will change the voltage drop of the power transistor according to the feedback signal of the output voltage, so that the output voltage remains stable. In simple terms, the input voltage minus the voltage drop of the power transistor equals the output voltage. The DC-DC converter uses the periodic conduction and cutoff of the switching element (such as MOSFET) to realize the conversion of voltage through energy storage elements such as inductors and capacitors. Common DC-DC converters include buck, boost, buck-boost, etc. Taking the buck DC-DC converter as an example, when the switching element is turned on, the input voltage supplies power to the load through the inductor and stores energy in the inductor; when the switching element is turned off, the energy in the inductor continues to supply power to the load through the freewheeling diode. The output voltage is adjusted by controlling the conduction time (duty cycle) of the switching element. In the utility model, the battery is a car battery, the voltage is 12V / 24V, and VCC_5V is output after LDO / DCDC voltage reduction. VCC_5V supplies power to the LED high drive circuit and also supplies power to other electrical loads.
[0043] In an alternative embodiment, as shown in Figure 2 The control module mainly includes a master control chip MCU and its peripheral circuit, which is used to send high / low level signals to control the LED on / off, and diagnose the circuit state through the ADC interface. The LED load and the high drive circuit are mainly connected through the wires at the LED interface. The voltage at the LED interface is divided by the first resistor R1 and the second resistor R2, and then collected by the ADC1 port of the MCU. After the MCU collects the data, it calculates the voltage at the LED interface, and judges the state of the entire circuit (normal working, short circuit, short power supply, short ground). The specific determination process is a conventional technical means in the art, and will not be described here. When the high drive circuit is working normally, the GPIO1 of the MCU outputs high voltage, the first transistor Q1 and the second transistor Q2 are turned on in turn, and the voltage at the LED interface is divided by the fourth resistor R4 and the fifth resistor R5. The third transistor Q3 cannot be turned on, and the third transistor Q3 is still in the off state. At this time, the circuit continues to work normally.
[0044] In an alternative embodiment, when the high drive circuit is shorted, the voltage at the LED interface becomes the shorted power supply voltage, after voltage division by the fourth resistor R4 and the fifth resistor R5, the third transistor Q3 is turned on, and the collector of the third transistor Q3 is directly connected to the base of the first transistor Q1, when the third transistor Q3 is turned on, the base of the first transistor Q1 is connected to GND, so that the first transistor Q1 and the second transistor Q2 are disconnected in turn, and the entire high drive circuit is hardware shut down and stops working, and the hardware shutdown time is very small, generally in the nanosecond / microsecond level. As can be seen, during the series of actions of ADC detection, judgment and pull-down of GPIO1 of the MCU, the high drive circuit inside has been hardware shut down, so the duration of the large increase in current in the circuit is very small, and the overcurrent protection mechanism of the LDO / DCDC does not need to be used for protection, and the device in the circuit will not be damaged, and the time when VCC_5V is raised to the shorted power supply voltage is also very small, and the circuit and other VCC_5V consumers will not be damaged and will not work abnormally.
[0045] The hardware shutdown circuit of the LED high drive provided by the utility model provides power supply through external power supply, under the detection and control of the control module, the LED load is driven by the high drive circuit to work in normal operation, and hardware shutdown is realized inside the high drive circuit in short circuit, and then logical shutdown is realized by the control module, so that the shutdown time can be reduced, and damage of the device in the circuit due to overcurrent can be avoided.
[0046] According to the embodiment of the utility model, on the other hand, a calling system is also provided, which comprises the hardware shutdown circuit of the LED high drive as shown in the figure. Figure 2
[0047] Specifically, in the utility model, the high drive circuit of the LED can be Figure 2 The hardware shutdown circuit of the shown LED high drive is applied to ECALL (Emergency-CALL) and BCALL (Breakdown-CALL) of a TBOX (Telematics BOX) product. ECALL is an emergency call rescue service, which is a phone call initiated by the vehicle owner or automatically triggered by the vehicle when an emergency occurs. When the vehicle is involved in a collision, triggers the airbag or other serious emergency, the system will automatically make an emergency call to directly connect the customer to the emergency call center. The staff of the call center will remotely talk to the vehicle and decide whether to activate relevant rescue agencies, such as contacting 120 emergency services, notifying the insurance company, etc., and assisting the driver to escape danger. In this process, when the ECALL button is pressed manually, the LED indicator will flash green, indicating that the emergency rescue call is being made. BCALL is a one-key phone rescue system, mainly used for road rescue. When the vehicle breaks down, such as being stranded, having a flat tire, engine failure, etc., the driver presses the BCALL button to send a distress signal to the background to obtain a series of help such as towing, repair personnel dispatch, etc. The background service center will arrange appropriate rescue resources to the scene according to the vehicle's location and fault information. In this process, after pressing the BCALL button, the LED may be on, possibly in a constant or flashing state of a specific color (such as yellow or blue, etc.), indicating that the vehicle is sending a fault distress signal to the background, or indicating that the background has received the signal and is processing it.
[0048] In addition, if the ECALL or BCALL system fails, the LED may change to a special flashing pattern or color to prompt the user that there is a problem with the system. For example, there may be a rapidly flashing red light to remind the user that the system is not working properly and needs to be checked and repaired. As can be seen, it is crucial to ensure the normal operation of the LED. The present application improves the high drive circuit to ensure that the circuit does not have the risk of overcurrent or overvoltage burnout.
[0049] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.
Claims
1. A high-drive circuit, characterized in that, include: The transistor consists of a first transistor, a second transistor, a third transistor, and a predetermined number of voltage divider resistors, wherein... The base of the first transistor is connected to the control port of the control module and the collector of the third transistor, and the collector of the first transistor is connected to the base of the second transistor. The emitter of the second transistor is connected to an external power supply, the collector of the second transistor is connected to an external load, the detection port of the control module is connected through a first voltage divider resistor, and the base of the third transistor is connected to a ground point and a second voltage divider resistor. The emitter of the first transistor, the emitter of the third transistor, the first voltage divider resistor, and the second voltage divider resistor are respectively connected to the ground point.
2. The high-drive circuit according to claim 1, characterized in that, The first voltage divider resistor includes a first resistor and a second resistor. The collector of the second transistor is connected to the first end of the first resistor; The second end of the first resistor is connected to the detection port of the control module and the first end of the second resistor, and the second end of the second resistor is connected to the grounding point; The collector of the first transistor is connected to the base of the second transistor through a third resistor.
3. The high-drive circuit according to claim 1, characterized in that, The second voltage divider resistor includes a fourth resistor and a fifth resistor. The collector of the second transistor is connected to the first end of the fourth resistor; The second end of the fourth resistor is connected to the base of the third transistor and the first end of the fifth resistor, and the second end of the fifth resistor is connected to the ground point.
4. The high-drive circuit according to claim 1, characterized in that, The first transistor and the third transistor are NPN transistors, and the second transistor is a PNP transistor.
5. A hardware shutdown circuit for an LED high-speed drive, characterized in that, include: External power supply, control module, LED load, and high-drive circuit as described in any one of claims 1 to 4; The external power supply is connected to the emitter of the second transistor in the high-drive circuit; The control port of the control module is connected to the base of the first diode in the high-drive circuit, and the detection port of the control module is connected to the first voltage divider resistor in the high-drive circuit. The LED load is connected to the collector of the second transistor.
6. The hardware shutdown circuit according to claim 5, characterized in that, The external power source includes: A storage battery, used to provide an external power source with a primary voltage; The voltage conversion module has its input terminal connected to the battery and its output terminal connected to the emitter of the second transistor, and is used to convert the external power supply of the first voltage into the second voltage.
7. The hardware shutdown circuit according to claim 6, characterized in that, The voltage conversion module is a low-dropout linear regulator or a DC-DC converter.
8. The hardware shutdown circuit according to claim 6, characterized in that, The first voltage is 12V or 24V, and the second voltage is 5V.
9. The hardware shutdown circuit according to claim 6, characterized in that, Also includes: An external electrical load is connected to the output terminal of the voltage conversion module.
10. A calling system, characterized in that, include: The hardware shutdown circuit for LED high-drive according to any one of claims 5 to 9.