Low-power-consumption CAN communication circuit with autonomous power-off control

Abstract

The utility model relates to a low-power-consumption CAN communication circuit with autonomous power-off control, which is used for realizing communication between a controller unit and a CAN bus and comprises a CAN transceiver chip, an N-channel MOS (Metal Oxide Semiconductor) tube, a P-channel MOS tube, an inductor, a first resistor, a second resistor, a third resistor and a fourth resistor, wherein the grid electrode of the P-channel MOS tube is connected with the source electrode of the power supply input end and the VCC pin of the CAN transceiver chip through a first resistor, and the drain electrode of the N-channel MOS tube is connected to the grid electrode of the power supply input end and is connected with the GPIO pin of the controller unit through a third resistor; the grid electrode of the N-channel MOS tube is connected with the source electrode of the grounding end through a fourth resistor, and the drain electrode of the grounding end is connected with the grid electrode of the P-channel MOS tube through a second resistor R2; and the inductor is connected among the CANL pin, the CANH pin and the differential signal receiving terminal of the CAN transceiver chip. According to the utility model, the CAN transceiver chip can be completely powered off when there is no communication, the problem of static power consumption of the communication chip in an idle state is solved, and a rapid wake-up function is supported.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and in particular to a low-power CAN communication circuit with autonomous power-off control. Background Technology

[0002] CAN communication is a serial communication protocol widely used in the automotive, industrial automation, and other fields. It enables efficient and reliable data transmission between multiple devices, offering advantages such as high anti-interference capability and strong real-time performance. In many devices, CAN communication is an essential component for enabling collaborative work and information exchange between devices.

[0003] Currently, most devices using CAN communication continue to be powered even when entering standby mode. For example, some automotive electronic devices keep their internal CAN communication modules powered even after the vehicle is turned off, so they can receive and send data at any time. While this ensures that the device can quickly respond to communication requests in standby mode, it leads to a waste of static power consumption. This power waste is particularly prominent in applications with high power consumption requirements, such as battery-powered portable devices or remote monitoring equipment.

[0004] To reduce static power consumption, some products currently employ software-based sleep mode. Specifically, when the device enters standby mode, software controls the CAN communication module to enter sleep mode, thereby reducing power consumption. However, this method has some drawbacks. First, it doesn't completely cut off power to the CAN communication circuitry, leaving some leakage current and preventing further power reduction. Second, this method heavily relies on MCU control, resulting in a relatively slow response time from high to low power consumption, which cannot meet the demands of applications with high real-time requirements. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a low-power CAN communication circuit with autonomous power-off control, which can realize the complete power-off of the CAN transceiver chip when there is no communication and support the fast wake-up function, effectively solving the static power consumption problem of the communication chip in the idle state.

[0006] To solve the above-mentioned technical problems, this utility model provides a low-power CAN communication circuit with autonomous power-off control, used to realize communication between the controller unit and the CAN bus, including: CAN transceiver chip, N-channel MOSFET, P-channel MOSFET, inductor, first resistor, second resistor, third resistor, and fourth resistor.

[0007] The gate of the P-channel MOSFET is connected to the source of the power input terminal and the VCC pin of the CAN transceiver chip via a first resistor, and the drain of the P-channel MOSFET is connected to the power input terminal. The gate of the N-channel MOSFET is connected to the GPIO pin of the controller unit via a third resistor, and the gate of the N-channel MOSFET is connected to the ground terminal via a fourth resistor. The drain of the N-channel MOSFET is connected to the gate of the P-channel MOSFET via a second resistor R2. The inductor is connected between the CANL pin, CANH pin and the differential signal receiving terminal of the CAN transceiver chip.

[0008] In one embodiment of this utility model, the CAN transceiver chip further includes a TXD pin, a GND pin, a SPLIT pin, and an STB pin. The GND pin and the STB pin are both connected to the ground terminal. The decoupling capacitor is connected between the SPLIT pin of the CAN transceiver chip and the ground terminal to filter out power supply noise.

[0009] In one embodiment of this utility model, a differential signal protection device is also included, one end of which is connected to an inductor and the other end is connected to a ground terminal.

[0010] In one embodiment of this utility model, the differential signal protection device is a bidirectional TVS diode array D1.

[0011] In one embodiment of this utility model, when the GPIO pin is configured to a high level, the N-channel MOSFET and the P-channel MOSFET are turned on, and the CAN transceiver chip is powered on; when the GPIO pin is configured to a low level, the N-channel MOSFET and the P-channel MOSFET, and the CAN transceiver chip are powered off.

[0012] In one embodiment of this utility model, the differential signal receiving terminal includes a CANH terminal and a CANL terminal, wherein the CANH terminal and the CANL terminal are respectively used to transmit high-level and low-level signals of the CAN bus.

[0013] In one embodiment of the present invention, the first resistor is used to maintain the gate voltage of the P-channel MOSFET at a high level when there is no signal driving, so that the P-channel MOSFET remains in the off state.

[0014] In one embodiment of this utility model, the second resistor is used to pull down the gate voltage of the P-channel MOSFET when the N-channel MOSFET is turned on, so as to control the conduction of the P-channel MOSFET.

[0015] In one embodiment of this invention, the third resistor and the fourth resistor are used to control the gate voltage of the N-channel MOSFET to achieve conduction control of the N-channel MOSFET.

[0016] Compared with the prior art, the above-mentioned technical solution of this utility model has the following beneficial effects:

[0017] The present invention discloses a low-power CAN communication circuit with autonomous power-off control. By controlling the conduction and cutoff of N-channel MOSFETs and P-channel MOSFETs through a controller unit, the CAN transceiver chip is completely powered off when there is no communication, and supports a fast wake-up function, effectively solving the static power consumption problem of the communication chip in the idle state. Attached Figure Description

[0018] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] Figure 1 This is a circuit diagram of a low-power CAN communication circuit with autonomous power-off control in a preferred embodiment of this utility model. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0021] Reference Figure 1 As shown in the figure, this utility model discloses a low-power CAN communication circuit with autonomous power-off control, which is used to realize communication between the controller unit MCU and the CAN bus. It is characterized by including: CAN transceiver chip U1, N-channel MOS transistor Q1, P-channel MOS transistor Q2, inductor L1, first resistor R1, second resistor R2, third resistor R3, and fourth resistor R4.

[0022] The gate of the P-channel MOSFET Q2 is connected to the power input terminal VCC through the first resistor R1; the source of the P-channel MOSFET Q2 is connected to the VCC pin of the CAN transceiver chip U1; and the drain of the N-channel MOSFET Q1 is connected to the power input terminal VCC.

[0023] The gate of the N-channel MOSFET Q2 is connected to the GPIO pin of the MCU through the third resistor R3; and the gate of the N-channel MOSFET Q2 is connected to the ground terminal IGND through the fourth resistor R4; the source of the N-channel MOSFET Q2 is connected to the ground terminal IGND; and the drain D of the N-channel MOSFET Q2 is connected to the gate of the P-channel MOSFET Q2 through the second resistor R2.

[0024] The inductor L1 is connected between the CANL pin, CANH pin and differential signal receiving terminal of the CAN transceiver chip U1.

[0025] Furthermore, the CAN transceiver chip U1 is also provided with a TXD pin, a GND pin, a SPLIT pin, and an STB pin. The GND pin and the STB pin are both connected to the ground terminal IGND, and the TXD pin is connected to the TXD pin of the microcontroller for transmitting data.

[0026] Furthermore, it also includes a decoupling capacitor C1, which is connected between the SPLIT pin of the CAN transceiver chip U1 and the ground terminal GND, and is used to filter out power supply noise.

[0027] Furthermore, it also includes a differential signal protection device, one end of which is connected to inductor L1 and the other end is connected to ground terminal IGND. The differential signal protection device is a bidirectional TVS diode array D1.

[0028] In this embodiment, when the GPIO pin is configured to a high level, the N-channel MOSFET Q1 and the P-channel MOSFET Q2 are turned on, supplying power to the CAN transceiver chip U1; when the GPIO pin is configured to a low level, the N-channel MOSFET Q1 and the P-channel MOSFET Q2 are turned off, cutting off the power supply to the CAN transceiver chip U1.

[0029] Preferably, the differential signal receiving terminal includes a CANH terminal and a CANL terminal, wherein the CANH terminal and the CANL terminal are used to transmit high-level and low-level signals of the CAN bus, respectively.

[0030] The first resistor R1 is used to maintain the gate voltage of the P-channel MOSFET Q2 at a high level when there is no signal driving, thus keeping the P-channel MOSFET Q2 in the off state. The second resistor R2 is used to pull down the gate voltage of the P-channel MOSFET Q2 when the N-channel MOSFET Q2 is turned on, thereby controlling the conduction of the P-channel MOSFET Q2. The third resistor R3 and the fourth resistor R4 are used to control the gate voltage of the N-channel MOSFET Q2, thereby achieving conduction control of the P-channel MOSFET Q2.

[0031] In this embodiment, the N-channel MOSFET Q1 acts as a low-side switch, and the P-channel MOSFET Q2 acts as a high-side switch. The microcontroller (MCU) controls the conduction and cutoff of the N-channel and P-channel MOSFETs through the GPIO pin. When the GPIO pin outputs a high level, the gate voltage of the N-channel MOSFET Q2 is pulled high through R3, turning on the P-channel MOSFET Q2. This, in turn, pulls down the gate voltage of the P-channel MOSFET Q2, turning on Q1, thereby powering the CAN transceiver chip.

[0032] When the GPIO pin outputs a low level, the gate voltage of the N-channel MOSFET Q1 is pulled low by R4, causing Q1 to turn off. This, in turn, causes the gate voltage of the P-channel MOSFET Q2 to return to a high level, turning off the P-channel MOSFET Q2 and cutting off the power supply to the CAN transceiver chip.

[0033] This cascaded configuration allows the use of a single GPIO pin to control the conduction state of two MOSFETs, thereby controlling the power supply of the CAN transceiver chip and achieving low power consumption and fast wake-up functionality.

[0034] A low-power CAN communication circuit with autonomous power-off control based on the above structure:

[0035] When the device enters sleep mode, a low-level signal is output through the GPIO port of the microcontroller MCU, so that both the N-channel MOSFET and the P-channel MOSFET are in the off state, thus cutting off the power supply to the CAN transceiver.

[0036] When the device needs to be woken up, a high-level signal is output through the GPIO port of the microcontroller MCU to turn on the N-channel MOSFET, and then turn on the P-channel MOSFET to power the CAN transceiver.

[0037] When the device needs to be powered off, a low-level signal is output through the GPIO port of the microcontroller MCU to turn off both the N-channel MOSFET and the P-channel MOSFET, thereby shutting down the power supply to the CAN transceiver.

[0038] Compared to traditional solutions, the standby current is reduced from 500uA to 0uA, significantly saving energy and extending the lifespan of the equipment, which is especially important for battery-powered devices. Furthermore, controlling the power supply via a MCU (Microcontroller Unit) offers greater flexibility, allowing for easy modification of power-off conditions without requiring hardware modifications.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A low-power CAN communication circuit with autonomous power-off control, used to realize communication between a controller unit and a CAN bus, characterized in that, include: CAN transceiver chip, N-channel MOSFET, P-channel MOSFET, inductor, first resistor, second resistor, third resistor and fourth resistor; The gate of the P-channel MOSFET is connected to the source of the power input terminal and the VCC pin of the CAN transceiver chip through a first resistor, and the drain of the P-channel MOSFET is connected to the power input terminal. The gate of the N-channel MOS transistor is connected to the GPIO pin of the controller unit through a third resistor, and the gate of the N-channel MOS transistor is connected to the ground terminal through a fourth resistor. The drain of the N-channel MOS transistor is connected to the gate of the P-channel MOS transistor through a second resistor R2. The inductor is connected between the CANL pin, CANH pin and differential signal receiving terminal of the CAN transceiver chip.

2. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: The CAN transceiver chip also includes a TXD pin, a GND pin, a SPLIT pin, and an STB pin. The GND pin and the STB pin are both connected to the ground terminal. The TXD pin is connected to the data transmission terminal of the microcontroller and is used to receive data signals from the MCU.

3. The low-power CAN communication circuit with autonomous power-off control according to claim 2, characterized in that: It also includes a decoupling capacitor connected between the SPLIT pin of the CAN transceiver chip and the ground terminal to filter out power supply noise.

4. The low-power CAN communication circuit with autonomous power-off control according to claim 3, characterized in that: It also includes a differential signal protection device, one end of which is connected to an inductor and the other end is connected to a ground terminal.

5. The low-power CAN communication circuit with autonomous power-off control according to claim 4, characterized in that: The differential signal protection device is a bidirectional TVS diode array.

6. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: When the GPIO pin is configured to a high level, the N-channel MOSFET and P-channel MOSFET are turned on, and the CAN transceiver chip is powered on; when the GPIO pin is configured to a low level, the N-channel MOSFET and P-channel MOSFET, and the CAN transceiver chip are powered off.

7. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: The differential signal receiving terminal includes a CANH terminal and a CANL terminal, which are used to transmit high-level and low-level signals of the CAN bus, respectively.

8. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: The first resistor is used to keep the gate voltage of the P-channel MOSFET at a high level when there is no signal driving, so that the P-channel MOSFET remains in the off state.

9. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: The second resistor is used to pull down the gate voltage of the P-channel MOSFET when the N-channel MOSFET is turned on, so as to control the conduction of the P-channel MOSFET.

10. The low-power CAN communication circuit with autonomous power-off control according to claim 1, characterized in that: The third and fourth resistors are used to control the gate voltage of the N-channel MOSFET to achieve conduction control of the N-channel MOSFET.

Images