Low-side driven circuit

Abstract

The utility model provides a low-side driving circuit, which comprises a power supply module, a control module and a low-side driving chip in communication connection with the control module, the power supply module is electrically connected with the control module and the low-side driving chip and is used for supplying power to the control module and the low-side driving chip; the output end of the low-side driving chip is electrically connected with the first end of the inductive load, the first end of the inductive load is electrically connected with the first end of the reverse electric release loop, and the second end of the reverse electric release loop is electrically connected with the power supply module. According to the utility model, the inductive load can be effectively driven, and the chip is prevented from overvoltage risk.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile control, in particular to a low-side drive circuit. Background Art

[0002] For mainstream manufacturers' multi-channel low-side driver chips, driving inductive loads (relay coils) in 24V systems does not require the support of additional auxiliary circuits. However, many manufacturers' clamping voltages are relatively low and cannot be directly applied in 24V systems. This will cause the reverse electromotive force generated by the disconnection of the inductive load to create an overvoltage risk for the low-side driver chip. Utility Model Content

[0003] The utility model provides a low-side drive circuit, which can effectively drive an inductive load while ensuring that the chip is not subject to overvoltage risks.

[0004] According to the utility model, a low-side drive circuit is provided, comprising: a power supply module, a control module, and a low-side drive chip connected to the control module for communication;

[0005] The power supply module is electrically connected to the control module and the low-side driver chip respectively, and is used to supply power to the control module and the low-side driver chip;

[0006] The output end of the low-side driver chip is connected to the first end of the inductive load, the first end of the inductive load is electrically connected to the first end of the reverse electric release loop, the second end of the reverse electric release loop is electrically connected to the power module, and the reverse electric release loop is used to release the reverse electric smoothly.

[0007] Optionally, the reverse electric release circuit includes a freewheeling diode; the first end of the inductive load is electrically connected to the positive electrode of the freewheeling diode, and the negative electrode of the freewheeling diode is electrically connected to the power module.

[0008] Optionally, the control module communicates with the low-side driver chip through an SPI protocol or an IIC protocol to perform read and write operations on registers in the low-side driver chip.

[0009] Optionally, the low-side driver chip further includes a MOS tube, which lowers the output voltage level when receiving a control instruction sent by the control module; and raises the output voltage level to the power supply voltage range when receiving a shutdown instruction sent by the control module.

[0010] Optionally, the input ends of the control module are electrically connected to a plurality of automobile function switches to obtain switch signals of corresponding functions of the automobile.

[0011] Optionally, the inductive load is a relay coil.

[0012] Optionally, the multiple output terminals of the low-side driver chip are respectively connected to the cathodes of multiple diodes, and the anodes of the multiple diodes are respectively connected to the relay control terminals of various functions of the vehicle.

[0013] Optionally, the anodes of the plurality of diodes are respectively connected to the first ends of the plurality of capacitors, and the second ends of the plurality of capacitors are grounded.

[0014] According to the technical solution of the embodiment of the present utility model, the output end of the low-side driver chip is electrically connected to the first end of the inductive load, the first end of the inductive load is also electrically connected to the first end of the reverse electric release circuit, and the second end of the reverse electric release circuit is electrically connected to the power module. The reverse electric power is smoothly released through the reverse electric release circuit, thereby effectively driving the inductive load while ensuring that the chip is not subject to overvoltage risks. Moreover, the utility model only needs to add an external reverse electric release circuit, making it more cost-effective to implement low-side driving.

[0015] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 1 is a schematic diagram of a low-side driver circuit provided according to an embodiment of the present utility model;

[0018] Figure 2 1 is a schematic diagram of another low-side driver circuit provided according to an embodiment of the present utility model;

[0019] Figure 3 This is a circuit diagram of a control module in one embodiment of a low-side driver circuit of the present invention;

[0020] Figure 4 This is a circuit diagram of the input portion of a control module in one embodiment of a low-side driver circuit of the present invention;

[0021] Figure 5 A circuit diagram of a low-side driver chip, an inductive load, and a freewheeling diode in one embodiment of a low-side driver circuit of the present invention;

[0022] Figure 6 The figure is a circuit diagram of a power module in one embodiment of a low-side drive circuit of the present invention. DETAILED DESCRIPTION

[0023] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] Figure 1 The utility model provides a schematic diagram of a low-side drive circuit. Figure 1 As shown, the circuit includes: a power module 1, a control module 2, and a low-side driver chip 3 that is connected to the control module 2 for communication;

[0026] The power supply module 1 is electrically connected to the control module 2 and the low-side driver chip 3 respectively, and is used to supply power to the control module 2 and the low-side driver chip 3;

[0027] The output end of the low-side driver chip 3 is electrically connected to the first end of the inductive load 4, the first end of the inductive load 4 is electrically connected to the first end of the reverse electric release circuit 5, the second end of the reverse electric release circuit 5 is electrically connected to the power module 1, and the reverse electric release circuit 5 is used to release the reverse electric smoothly.

[0028] Power module 1 is a DC power supply used to power the control module and low-side driver chip. The power module may include a voltage regulator. Control module 2 is used to receive a trigger signal from the corresponding vehicle function at its input terminal and send a control signal to low-side driver chip 3. After receiving the trigger signal from the corresponding vehicle function, low-side driver chip 3 sets the corresponding function's drive output terminal to a low level, thereby driving the corresponding vehicle function.

[0029] In this embodiment, the output end of the low-side driver chip 3 is connected to the first end of an inductive load 4. The number of inductive loads can be the same as the number of functions required to be driven by the vehicle. When the first end of the inductive load 4 receives a low-level signal, it turns on, causing the vehicle function corresponding to the inductive load 4 to begin operating. Furthermore, the first end of the inductive load 4 is also electrically connected to the first end of a reverse electromotive force release circuit 5. The second end of the reverse electromotive force release circuit 5 is connected to the power module. When the output end of the low-side driver chip 3 is suddenly set to a high level and the inductive load 4 is disconnected, the sudden voltage generated across the inductive load 4 will input a reverse electromotive force into the power module 1 and the low-side driver chip 3. Because the output end of the low-side driver chip 3 is set to a high level and at a relatively high voltage, the reverse electromotive force will not damage the low-side driver chip 3. Furthermore, the presence of the reverse electromotive force release circuit 5 ensures a smooth reverse electromotive force release.

[0030] According to the technical solution of the embodiment of the present utility model, the output end of the low-side driver chip 3 is electrically connected to the first end of the inductive load 4, the first end of the inductive load 4 is also electrically connected to the first end of the reverse electric release circuit 5, and the second end of the reverse electric release circuit 5 is electrically connected to the power module. The reverse electric power is smoothly released through the reverse electric release circuit 5, thereby effectively driving the inductive load 4 while ensuring that the chip is not subject to overvoltage risks. In addition, the utility model only needs to add an external reverse electric release circuit 5, which makes it cheaper to implement low-side driving.

[0031] In such Figure 2 In the illustrated embodiment, the reverse electric release circuit 5 includes a freewheeling diode; the first end of the inductive load is electrically connected to the positive electrode of the freewheeling diode, and the negative electrode of the freewheeling diode is electrically connected to the power module 1 .

[0032] A freewheeling diode is a diode used with inductive loads. When the current of an inductive load suddenly changes or decreases, a sudden voltage is generated across the inductor, potentially damaging other components. Using a freewheeling diode allows the current to change more smoothly, avoiding voltage surges. In this embodiment, by electrically connecting the first end of the inductive load to the positive electrode of the freewheeling diode and the negative electrode of the freewheeling diode to the power module, the current generated by the sudden voltage across the inductive load changes smoothly due to the freewheeling diode, thus preventing any impact on the power module.

[0033] In one embodiment, the control module 2 communicates with the low-side driver chip 3 via the SPI protocol or the IIC protocol to perform read and write operations on registers in the low-side driver chip 3 .

[0034] The control module 2 may be an MCU chip, which may communicate with the low-side driver chip 3 via a communication port. In this embodiment, the MCU chip may communicate with the low-side driver chip via the MOSI, MISO, SCK, and CS ports. When the MCU chip receives an input of a vehicle function signal, the MCU transmits a control signal corresponding to the vehicle function signal to the low-side driver chip 3 via the communication port, thereby performing read and write operations on the registers within the low-side driver chip 3.

[0035] In one embodiment, the low-side driver chip 3 further includes a MOS transistor, which lowers the output voltage level when receiving a control instruction sent by the control module 2; and raises the output voltage level to the power supply voltage range when receiving a shutdown instruction sent by the control module.

[0036] The low-side driver chip 3 also includes a MOS transistor, which can generally be an NMOS transistor. Based on a received control instruction, the low-side driver chip 3 sets the drive output terminal corresponding to the corresponding vehicle function to a low level, thereby controlling the inductive load of the corresponding vehicle function. Based on a received control instruction, the low-side driver chip 3 sets the drive output terminal corresponding to the corresponding vehicle function to a high level, thereby shutting off the inductive load of the corresponding vehicle function. In this embodiment, when shutting off the inductive load, the voltage level at the output terminal of the low-side driver chip 3 can be raised to the supply voltage range to reduce the voltage difference between the output terminal of the low-side driver chip 3 and the inductive load, thereby preventing the back electromotive force generated when the inductive load is shut off from burning out the low-side driver chip 3.

[0037] In one embodiment, the input terminals of the control module are electrically connected to a plurality of automobile function switches to obtain switch signals of corresponding automobile functions.

[0038] The input terminals of the control module 2 can be electrically connected to multiple vehicle function switches, thereby obtaining switch signals when the multiple vehicle function switches are actuated. In this embodiment, the control module 2 can be connected to eight vehicle function switches, including the front position light switch, high beam switch, low beam switch, left front fog light switch, right front fog light switch, rearview mirror heating switch, low-speed wiper switch, and high-speed wiper switch.

[0039] In one embodiment, the inductive load is a relay coil. The multiple output terminals of the low-side driver chip are respectively connected to the cathodes of multiple diodes, and the anodes of the multiple diodes are respectively connected to the relay control terminals of various functions of the vehicle.

[0040] Specifically, such as Figure 2 The schematic diagram of the low-side driver circuit is shown in Figure 2 The central control module 2 is an MCU, and the reverse electric release circuit 5 includes a freewheeling diode. The power module 1 is connected to the MCU and the low-side driver chip 3, respectively, for supplying power to the MCU and the low-side driver chip 3. The MCU includes eight input terminals connected to vehicle function switches. When the eight vehicle function switches are activated, the MCU inputs switch signals corresponding to the vehicle functions into the MCU. The MCU is electrically connected to the low-side driver chip 3 through a communication port. The MCU transmits control signals corresponding to the vehicle functions to the low-side driver chip 3 via the communication port. Upon receiving the control signals, the low-side driver chip 3 sets its output terminal to a low level to drive the inductive load corresponding to the vehicle function. The inductive load can be a relay coil. The eight output terminals of the low-side driver chip are respectively connected to eight relay coils, each corresponding to one of the eight vehicle functions: front position lights, high beam, low beam, left front fog light, right front fog light, heated rearview mirror, low-speed wiper, and high-speed wiper. The first terminal of the relay coil is electrically connected to the positive electrode of the freewheeling diode, and the negative electrode of the freewheeling diode is electrically connected to the power module 1 to smoothly discharge the sudden current generated when the relay coil is suddenly disconnected.

[0041] In one embodiment, the control module 2 may be selected as follows: Figure 3 The chip shown in the figure can be S12G96, S12G128, 100pin. The chip includes 8-to-1 channel selection interfaces YC1, YB1, and YA1 for connecting to the input end. It also includes an SPI communication port for communicating with the low-side driver chip. The SPI communication port includes four ports: MOSI, MISO, SCK, and CS.

[0042] In one embodiment, the input end of the control module 2 includes 8 vehicle function switches, specifically Figure 4As shown, the eight switches include a front position light switch, a high beam switch, a low beam switch, a left front fog light switch, a right front fog light switch, a rearview mirror heating switch, a wiper low speed switch, and a wiper high speed switch. The eight switches correspond to an 8-to-1 channel selection interface for receiving switch action signals.

[0043] The connection relationship between the low-side driver chip 3, the inductive load 4 and the freewheeling diode is as follows: Figure 5 As shown, Figure 5 The mid- and low-side driver chip 3 is connected to the control module 2 via a communication port. The communication interface includes four ports: MOSI, MISO, SCK, and CS. The low-side driver chip 3 also includes eight output terminals OUT1-OUT8 connected to the relay drive terminal. Each output terminal of the low-side driver chip 3 is connected to the cathode of a diode. The anode of the diode is connected to the first segment of the capacitor, the first end of the freewheeling diode, and the relay drive terminal. The second end of the capacitor is grounded, and the second end of the freewheeling diode is connected to the power module 1.

[0044] The circuit diagram of power module 1 is as follows Figure 6 As shown, Figure 6 The power supply module 1 includes a power supply circuit, the input end of the power supply circuit is connected to the negative electrode of the freewheeling diode D20, the first end of the first resistor of the power supply circuit is the input end of the power supply circuit, the second end of the first resistor is respectively connected to the first end of the first capacitor and the input end of the voltage regulator, the second end of the first capacitor is grounded, the ground end of the voltage regulator is grounded, the output end of the voltage regulator is respectively connected to the first end of the second capacitor, the MCU and the power supply port of the low-side driver chip, and the second end of the second capacitor is grounded. Figure 6 The medium voltage regulator uses the BD750L5FP-C model.

[0045] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this utility model can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this utility model can be achieved. This is not limited herein.

[0046] The above specific embodiments do not limit the scope of protection of this utility model. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model shall be included within the scope of protection of this utility model.

Claims

1. A low-side driver circuit, characterized in that: It includes a power module, a control module, and a low-side driver chip that is connected to the control module in communication; The power supply module is electrically connected to the control module and the low-side driver chip respectively, and is used to supply power to the control module and the low-side driver chip; The output end of the low-side driver chip is connected to the first end of the inductive load, the first end of the inductive load is electrically connected to the first end of the reverse electric release loop, the second end of the reverse electric release loop is electrically connected to the power module, and the reverse electric release loop is used to release the reverse electric smoothly.

2. The low-side driver circuit according to claim 1, wherein: The reverse electric release circuit includes a freewheeling diode; the first end of the inductive load is electrically connected to the positive electrode of the freewheeling diode, and the negative electrode of the freewheeling diode is electrically connected to the power module.

3. The low-side driver circuit according to claim 1, wherein: The control module communicates with the low-side driver chip through the SPI protocol or the IIC protocol to perform read and write operations on the registers in the low-side driver chip.

4. The low-side driver circuit according to claim 1, wherein: The low-side driver chip further includes a MOS transistor, which lowers the output voltage level when receiving a control instruction sent by the control module; and raises the output voltage level to a power supply voltage range when receiving a shutdown instruction sent by the control module.

5. The low-side driver circuit according to claim 1, wherein: The input ends of the control module are electrically connected to a plurality of automobile function switches to obtain switch signals of corresponding automobile functions.

6. The low-side driver circuit according to claim 1, wherein: The inductive load is a relay coil.

7. The low-side driver circuit according to claim 6, wherein: The multiple output terminals of the low-side driver chip are respectively connected to the cathodes of the multiple diodes, and the anodes of the multiple diodes are respectively connected to the relay control terminals of the various functions of the vehicle.

8. The low-side driver circuit according to claim 7, wherein: Anodes of the plurality of diodes are respectively connected to first ends of the plurality of capacitors, and second ends of the plurality of capacitors are grounded.

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