Microcontroller WITH 128K BYTES OF ISP FLASH AND CAN CONTROLLER# AT90CAN12816AU Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The AT90CAN12816AU microcontroller is specifically designed for applications requiring robust communication capabilities and reliable performance in demanding environments:
Industrial Control Systems
- PLC (Programmable Logic Controller) implementations : The integrated CAN controller enables reliable communication in industrial automation networks
- Motor control systems : 128KB flash memory accommodates complex control algorithms while the 16MHz operation provides sufficient processing speed
- Sensor data acquisition : Multiple ADC channels (8-channel 10-bit ADC) allow for comprehensive sensor monitoring
Automotive Applications
- Body control modules : CAN 2.0A/B compatibility ensures seamless integration with automotive networks
- Diagnostic systems : Real-time monitoring capabilities with the integrated CAN controller
- Climate control systems : Multiple I/O ports support various sensor inputs and actuator outputs
Medical Equipment
- Patient monitoring devices : Low-power modes (6 sleep modes) enable extended battery operation
- Portable medical instruments : Robust CAN communication ensures reliable data transmission in critical applications
### Industry Applications
Industrial Automation
- Advantages :
- CAN interface eliminates need for external CAN controllers
- Industrial temperature range (-40°C to +85°C) ensures reliable operation
- 128KB flash memory supports complex control algorithms
- Limitations :
- Limited to 16MHz maximum frequency may not suit high-speed processing requirements
- 4KB SRAM may be insufficient for extremely data-intensive applications
Automotive Electronics
- Advantages :
- AEC-Q100 qualification potential (consult manufacturer for specific grading)
- CAN 2.0B compliant with 15 message objects
- Robust EEPROM (4KB) for critical parameter storage
- Limitations :
- Requires external CAN transceiver for physical layer implementation
- Limited number of PWM channels (4) for complex motor control applications
Building Automation
- Advantages :
- Multiple communication interfaces (USART, SPI, TWI) complement CAN functionality
- Low-power operation modes suitable for energy-efficient systems
- Sufficient I/O (53 programmable I/O lines) for comprehensive control tasks
### Practical Advantages and Limitations
Key Advantages
- Integrated CAN Controller : Reduces component count and board space
- Large Memory Capacity : 128KB flash + 4KB EEPROM + 4KB SRAM
- Industrial Temperature Range : Suitable for harsh environments
- Multiple Communication Interfaces : USART, SPI, TWI alongside CAN
Notable Limitations
- Processing Speed : Maximum 16MHz may limit performance in compute-intensive applications
- Memory Architecture : Harvard architecture may require adaptation for certain applications
- Package Size : 64-pin TQFP package requires careful PCB layout consideration
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Power Supply Design
- Pitfall : Inadequate decoupling causing unstable operation
- Solution : Implement 100nF ceramic capacitors at each power pin, plus 10μF bulk capacitor near the device
Clock Circuit Design
- Pitfall : Poor crystal oscillator layout leading to startup failures
- Solution :
- Place crystal and load capacitors close to XTAL pins
- Use ground plane beneath oscillator circuit
- Keep oscillator traces short and symmetrical
CAN Bus Implementation
- Pitfall : Incorrect termination causing communication errors
- Solution :
- Implement 120Ω termination resistors at both ends of CAN bus
- Use proper CAN transceiver (e.g., MCP2551) with adequate ESD protection
### Compatibility Issues
Voltage Level Compatibility
- Issue : 5V I/O compatibility in mixed-voltage
