The low-power CAN bus module is a CAN (Controller Area Network) bus communication component designed to reduce communication power consumption. It is mainly used in battery-powered or energy-sensitive scenarios (such as the Internet of Things, automotive electronics, industrial sensors, etc.). On the basis of maintaining the original high reliability, real-time and multi-master communication characteristics of the CAN bus, it significantly reduces the current consumption of the module in working state, standby state and even sleep state through hardware architecture optimization, power management technology and protocol improvement.
Ⅰ. Core Definition and Objectives
Although the traditional CAN bus (classic CAN or CAN FD) has high reliability, the power consumption of components such as transceivers and controllers in traditional designs is high (for example, the operating current of traditional CAN transceivers may reach 10-30 mA, and the standby current may also be at the mA level), which makes it difficult to meet the long-term battery life requirements of battery-powered devices (such as Internet of Things nodes and vehicle-mounted sleep modules).
The goal of low-power CAN bus modules is to reduce the operating current to several mA and the standby/sleep current to μA (the standby current of some modules can be as low as 1 μA or less) while ensuring the communication quality, thereby extending the battery life of the device (for example, AA batteries can support several months to several years).
Ⅱ.Key technologies and implementation methods
The low power consumption characteristics of the low-power CAN bus module rely on the following core technologies:
1. Low-power transceiver design
The physical layer of the CAN bus relies on the transceiver to realize the conversion between the bus level and the logic signal. The low-power module uses optimized transceiver chips (such as TI TCAN330xx, NXP TJA1059i) to reduce power consumption in the following ways:
Sleep mode: When there is no communication on the bus, the transceiver automatically enters an extremely low power mode (such as turning off the internal oscillator, disconnecting some circuits), and only retains the bus wake-up function (current as low as 1-10 μA).
Dynamic current control: Dynamically adjust the drive current according to the bus load (such as whether there is data transmission) to avoid unnecessary power consumption.
Integrated voltage resistance and protection: Integrated bus fault protection (such as ±30 V voltage resistance), over-temperature protection, etc., reduce the need for external protection circuits, simplify the design and reduce additional power consumption.
2. Collaborative low-power design with MCU
Low-power CAN modules are usually deeply integrated with microcontrollers (MCUs) (or connected via SPI/UART), and the overall power consumption is reduced through the power management function of the MCU:
Synchronous sleep: When the MCU detects that there is no communication demand, it notifies the CAN module to enter sleep and enters low-power mode itself (such as stopping the clock and turning off peripherals).
Fast wake-up: Trigger the module and MCU to wake up quickly (wake-up time is usually <100μs) through bus signals (such as dominant bits) or external interrupts (such as GPIO) to ensure timely response to critical communications.
3. Protocol optimization and selective wake-up
Selective wake-up: Traditional CAN bus wake-up requires all nodes to monitor the bus, while low-power modules support only specific nodes to be woken up (by identifying specific IDs or data frames on the bus), reducing the power consumption caused by invalid wake-up.
Short frame communication: Optimize the communication protocol, reduce the length of the data frame (such as using standard frames instead of extended frames), shorten the bus occupancy time, and reduce the active power consumption of the transceiver.
Event-driven mode: The module is activated only when data needs to be sent/received, and remains dormant the rest of the time (for example, a sensor wakes up to communicate only when data changes).
Ⅲ.Key technologies and implementation methods
The low power consumption characteristics of the low-power CAN bus module rely on the following core technologies:
1. Low-power transceiver design
The physical layer of the CAN bus relies on the transceiver to realize the conversion between the bus level and the logic signal. The low-power module uses optimized transceiver chips (such as TI TCAN330xx, NXP TJA1059i) to reduce power consumption in the following ways:
Sleep mode: When there is no communication on the bus, the transceiver automatically enters an extremely low power mode (such as turning off the internal oscillator, disconnecting some circuits), and only retains the bus wake-up function (current as low as 1-10 μA).
Dynamic current control: Dynamically adjust the drive current according to the bus load (such as whether there is data transmission) to avoid unnecessary power consumption.
Integrated voltage resistance and protection: Integrated bus fault protection (such as ±30 V voltage resistance), over-temperature protection, etc., reduce the need for external protection circuits, simplify the design and reduce additional power consumption.
2. Collaborative low-power design with MCU
Low-power CAN modules are usually deeply integrated with microcontrollers (MCUs) (or connected via SPI/UART), and the overall power consumption is reduced through the power management function of the MCU:
Synchronous sleep: When the MCU detects that there is no communication demand, it notifies the CAN module to enter sleep and enters low-power mode itself (such as stopping the clock and turning off peripherals).
Fast wake-up: Trigger the module and MCU to wake up quickly (wake-up time is usually <100μs) through bus signals (such as dominant bits) or external interrupts (such as GPIO) to ensure timely response to critical communications.
3. Protocol optimization and selective wake-up
Selective wake-up: Traditional CAN bus wake-up requires all nodes to monitor the bus, while low-power modules support only specific nodes to be woken up (by identifying specific IDs or data frames on the bus), reducing the power consumption caused by invalid wake-up.
Short frame communication: Optimize the communication protocol, reduce the length of the data frame (such as using standard frames instead of extended frames), shorten the bus occupancy time, and reduce the active power consumption of the transceiver.
Event-driven mode: The module is activated only when data needs to be sent/received, and remains dormant the rest of the time (for example, a sensor wakes up to communicate only when data changes).
Ⅲ.typical application scenarios
The core advantage of low-power CAN bus modules is "low power consumption + reliable communication", so they are widely used in the following scenarios:
1. Battery-powered Internet of Things (IoT) nodes
Such as environmental monitoring sensors (temperature, humidity, light), industrial instruments (pressure, flow), smart meters, etc. These devices usually rely on battery power (such as AA batteries, lithium batteries), and the batteries need to be replaced every few months or even years. Low-power CAN modules can significantly extend the battery life.
2. Sleep modules in automotive electronics
After the car is turned off, many subsystems (such as door control, seat adjustment, tire pressure monitoring, and on-board sensors) need to enter sleep mode to save power (avoid battery consumption). Low-power CAN modules support bus wake-up (such as key signal triggering) to ensure that key commands can still be responded to in sleep mode.
3. Industrial Wireless Sensor Network (WSN)
In industrial sites, sensor nodes may be distributed in a wide area (such as factory workshops and along pipelines), which are difficult to maintain. Low-power CAN modules support long-term sleep + event wake-up, reduce the frequency of active node communication, and extend the life of the equipment.
4. Smart home devices
Such as smart door locks, door and window sensors, air conditioner remote controls, etc. These devices are usually battery-powered and only need to communicate when the state changes (such as opening a door or pressing a button). Low-power CAN modules can balance the requirements of "low power consumption" and "real-time response".
Ⅳ. When choosing a low-power CAN bus module, you need to focus on power consumption indicators (working/standby current), communication performance (baud rate, protocol compatibility), interface flexibility, package size and application scenario adaptability. The following is a recommendation and analysis of high-quality modules for different needs:
1.EBYTE E78 series (CAN to 4G/NB-IoT low-power module)
Positioning: Industrial IoT gateway, supports CAN bus data upload to the cloud via 4G/NB-IoT.
Core models: E78-868D (European frequency band), E78-900D (North American frequency band), E78-4G01 (4G full network access).
Key features:
CAN interface: 1 CAN 2.0A/B (1 Mbps), supports standard frame/extended frame;
Low power design:
Normal working current: ≤30 mA (when CAN communication);
Deep sleep current: ≤10 μA (turn off CAN and wireless module, only keep wake-up circuit);
Support bus wake-up (triggered by CAN signal) or timed wake-up (configured by AT command);
Wireless communication: integrated 4G Cat.1/NB-IoT module (such as Quectel EC20/BC28), supports TCP/UDP/HTTP/MQTT protocol;
Interface expansion: supports UART, GPIO, ADC, etc., compatible with 3.3 V/5 V system;
Industrial protection: metal shielding shell, surge resistance ±4 kV, pulse group resistance ±2 kV, suitable for industrial sites;
Software support: provides AT instruction set, Android/iOS APP (EBYTE Tool) and PC configuration tools, supports data transparent transmission and remote management.
Applicable scenarios: remote monitoring of industrial equipment (such as PLC, motor controller), smart meter/water meter reading, vehicle-mounted T-BOX (requires CAN+4G communication).
2.EBYTE E104 series (low-power CAN to UART module)
Positioning: low-cost CAN bus expansion module for local CAN communication of embedded devices.
Core models: E104-CAN1 (basic version), E104-CAN2 (dual-channel CAN version).
Key features:
CAN interface: single/dual CAN 2.0A/B (1 Mbps), support automatic baud rate detection (optional);
Low power mode:
Normal mode: working current ≤25 mA (CAN communication);
Sleep mode: ≤5 μA (need external interrupt wake-up, such as GPIO or bus signal);
Fast wake-up: bus dominant bit or external wake-up signal trigger, wake-up time <100 μs;
Level compatibility: support 3.3 V/5 V MCU interface (TX/RX level automatic matching);
Protection function: integrated bus transceiver (similar to TJA1050), support ±15 V bus withstand voltage, overcurrent protection;
Configuration method: support jumper cap configuration (such as baud rate, wake-up mode) or AT command (need to cooperate with EBYTE serial port assistant).
Applicable scenarios: smart home sensors (such as multi-parameter monitoring of temperature and humidity + CAN communication), industrial field equipment debugging (replacing traditional CAN debugger), small PLC expansion CAN port.
3.EBYTE E22 series (CAN to LoRa low power module)
Positioning: Low power wide area network (LPWAN) scenario, supports long-distance transmission of CAN bus data via LoRa (1~20 km).
Core models: E22-900M22S (900 MHz LoRa), E22-433M22S (433 MHz LoRa).
Key features:
CAN interface: 1 CAN 2.0A/B (500 kbps, supports speed reduction to adapt to LoRa bandwidth);
Low power design:
Normal working current: ≤20 mA (CAN communication + LoRa transmission);
Deep sleep current: ≤2 μA (only LoRa reception wake-up is retained);
Support bus event wake-up (such as specific ID data frame trigger) or timed wake-up;
LoRa communication: supports half-duplex communication, transmission power 20 dBm (100 mW), receiving sensitivity -137 dBm (SF12, 125 kHz);
Anti-interference: built-in FEC error correction, automatic retransmission, adapt to industrial electromagnetic environment;
Configuration method: support AT commands or supporting software (EBYTE LoRa Config Tool) to set parameters such as channel and rate.
Applicable scenarios: Agricultural Internet of Things (such as greenhouse environment monitoring + equipment control), water conservancy monitoring (reservoir/river sensor network), and long-distance industrial sensor nodes.
4. ZHIYEE ZCAN series low-power CAN modules
Manufacturer background: ZHIYEE is a leading domestic IoT communication module manufacturer, focusing on low-power wireless and wired communication modules, with products covering CAN, 4G/5G, LoRa, etc.
Core models: ZCAN301 (low-power CAN to UART/USB module), ZCAN302 (CAN FD to UART).
Key features:
Based on NXP TJA1059i low-power transceiver + STM32 MCU, supports classic CAN (1 Mbps) and CAN FD (2 Mbps);
Working current: ≤20 mA in normal mode, ≤1μA in deep sleep (retain bus wake-up capability);
Rich interfaces: support UART, USB, GPIO, compatible with 3.3 V/5 V levels;
Package: small-size PCB module (22mm×15mm), evaluation board (ZCAN-EVB) and supporting host computer software are provided;
Certification: Some models have passed industrial-grade temperature (-40℃~+85℃) and EMC tests.
Applicable scenarios: smart home sensors (such as temperature and humidity monitoring), industrial equipment debugging, drone flight control communication.
5. Shanghai Belling BL8023 low-power CAN transceiver module
Manufacturer background: Shanghai Belling is a leading domestic analog chip company. Its CAN transceiver module has high integration and is suitable for automotive electronics.
Core model: BL8023 (low-power CAN transceiver + MCU module).
Key features:
Built-in BL8023 low-power transceiver (working current ≤12 mA, standby ≤8 μA) + low-power MCU (ST L0 series);
Supports CAN 2.0B (1 Mbps), compatible with 3.3 V/5 V system;
Provides sleep mode (only bus wake-up is retained), supports local/remote wake-up;
The module is AEC-Q100 Grade 2 certified (-40℃~+105℃);
Package: SMD-14 (small size, suitable for PCB mounting).
Applicable scenarios: automotive body control module (BCM), vehicle lighting control, new energy vehicle BMS (battery management system) sensor.