CJMCU-230 SN65HVD230 CAN Bus Transceiver Communication Module – Support Documentation
Product Overview:
The CJMCU-230 module is a compact CAN (Controller Area Network) transceiver based on the Texas Instruments SN65HVD230 chip. Designed for high-speed, reliable communication, it supports the ISO 11898-2 standard and is ideal for automotive, industrial, and automation applications. Operating at 3.3V, it’s compatible with microcontrollers like Arduino, STM32, and ESP32.
Key Features:
- High-speed CAN communication up to 1 Mbps
- 3.3V operating voltage
- Low current standby mode (370 μA typical)
- Thermal shutdown and short-circuit protection
- Supports up to 120 nodes on the CAN bus
- Compact design: 30mm x 20mm
Pinout Configuration
| Pin | Label | Description |
|---|---|---|
| 1 | 3V3 | 3.3V Power Supply |
| 2 | GND | Ground |
| 3 | CTX | CAN Transmit Input (TXD) |
| 4 | CRX | CAN Receive Output (RXD) |
| 5 | CANH | CAN High Bus Line |
| 6 | CANL | CAN Low Bus Line |
Electrical Specifications
| Parameter | Value |
|---|---|
| Operating Voltage | 3.3V |
| Bus Voltage Range | -2V to +7V |
| Data Rate | Up to 1 Mbps |
| Standby Current | 370 μA (typical) |
| ESD Protection | ±16 kV (HBM) on bus pins |
| Common-Mode Range | -2V to +7V |
Typical Application Circuit
Connect the CJMCU-230 module to your microcontroller and CAN bus as follows:
- 3V3: Connect to 3.3V power supply
- GND: Connect to ground
- CTX: Connect to microcontroller’s CAN TX pin
- CRX: Connect to microcontroller’s CAN RX pin
- CANH: Connect to CAN bus high line
- CANL: Connect to CAN bus low line
Ensure 120Ω termination resistors are placed at both ends of the CAN bus to minimize signal reflections.
Operating Modes
The SN65HVD230 transceiver supports three operating modes controlled via the RS (slope control) pin:
- High-Speed Mode: RS pin connected to GND. Allows fastest data rates with no slope control.
- Slope Control Mode: RS pin connected to GND through a resistor. Controls the rise and fall times to reduce EMI.
- Standby Mode: RS pin connected to VCC. Puts the device into low-power standby mode.
Note: Some CJMCU-230 modules have the RS pin internally configured. Verify your module’s configuration before use.
Best Practices
- Use twisted-pair cables for CANH and CANL lines to reduce noise.
- Keep CAN bus lines as short as possible to minimize signal degradation.
- Ensure all devices on the CAN bus share a common ground reference.
- Place 120Ω termination resistors at both ends of the CAN bus.
- Use proper shielding in high EMI environments.
Troubleshooting
| Issue | Possible Cause | Solution |
|---|---|---|
| No communication | Incorrect wiring or missing termination resistors | Verify connections and ensure 120Ω resistors are in place |
| Data errors | Excessive bus length or noise | Shorten bus length and use twisted-pair cables |
| Module overheating | Short circuit on CANH/CANL lines | Inspect for shorts and correct wiring issues |
Frequently Asked Questions (FAQs)
- Q: Can I use the CJMCU-230 with a 5V microcontroller?
- A: Yes, but you’ll need level shifters or voltage dividers to interface the 3.3V CJMCU-230 with 5V logic levels.
- Q: Is the CJMCU-230 compatible with CAN 2.0B?
- A: Yes, the SN65HVD230 transceiver supports CAN 2.0B protocol.
- Q: What is the maximum number of nodes supported on the CAN bus?
- A: The SN65HVD230 supports up to 120 nodes on the CAN bus.