8-bit Microcontroller with 128K Bytes of ISP Flash and CAN Controller# AT90CAN12816MI Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The AT90CAN12816MI is an 8-bit AVR microcontroller with integrated CAN controller, making it particularly suitable for applications requiring robust communication in electrically noisy environments. Typical implementations include:
Industrial Control Systems
- PLC Integration : Serves as local controller in distributed PLC systems
- Motor Control : Brushless DC motor control with CAN-based communication
- Sensor Networks : Aggregates data from multiple sensors with CAN backbone
- Process Automation : Real-time monitoring and control in manufacturing environments
Automotive Applications
- Body Control Modules : Door, window, and seat control systems
- Powertrain Management : Auxiliary control functions in engine management
- Infotainment Systems : Peripheral control with CAN communication
- Diagnostic Systems : On-board diagnostic data collection and reporting
Medical Equipment
- Patient Monitoring : Vital signs monitoring with reliable data transmission
- Laboratory Instruments : Analytical equipment requiring noise-immune communication
- Therapeutic Devices : Controlled dosage delivery systems
### Industry Applications
Industrial Automation
- Advantages :
- CAN 2.0A/B compatibility ensures reliable communication in noisy factory environments
- 128KB flash memory accommodates complex control algorithms
- Industrial temperature range (-40°C to +85°C) suitable for harsh conditions
- Limitations :
- 8-bit architecture may limit computational intensity for complex mathematical operations
- Limited to single CAN controller interface
Automotive Systems
- Advantages :
- AEC-Q100 qualification potential for automotive applications
- Low power consumption modes extend battery life
- Hardware CRC generator enhances data integrity
- Limitations :
- Requires external transceivers for CAN physical layer
- Limited number of CAN mailboxes (15) may constrain complex network topologies
Building Automation
- Advantages :
- Multiple communication interfaces (CAN, SPI, I²C, UART) provide flexibility
- Real-time clock with calendar functionality
- Brown-out detection for power stability
- Limitations :
- Higher cost compared to basic microcontrollers without CAN capability
### Practical Advantages and Limitations
Key Advantages
- Communication Reliability : Hardware CAN controller with error detection and correction
- Memory Capacity : 128KB flash + 4KB EEPROM + 4KB SRAM for data-intensive applications
- Peripheral Integration : Multiple timers, ADC, and communication interfaces reduce BOM
- Development Support : Extensive Atmel/Microchip development tools and libraries
Notable Limitations
- Processing Power : 8-bit architecture limits performance for computationally intensive tasks
- CAN Implementation : Single CAN controller limits complex network participation
- Package Options : Limited to 64-pin QFP package, restricting miniaturization possibilities
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Power Management Issues
- Pitfall : Inadequate decoupling causing erratic behavior
- Solution : Implement 100nF ceramic capacitors at each power pin, plus 10μF bulk capacitor near the device
Clock Configuration
- Pitfall : Incorrect fuse bit settings leading to unstable operation
- Solution : Use production programming tools to verify fuse settings before mass production
CAN Network Design
- Pitfall : Improper termination causing signal reflection
- Solution : Include 120Ω termination resistors at both ends of the CAN bus
### Compatibility Issues
Voltage Level Compatibility
- Issue : 5V I/O levels may not be compatible with modern 3.3V peripherals
- Resolution : Use level shifters or select 5V-tolerant external components
CAN Transceiver
