High Accuracy 61 g to 65 g Single Axis iMEMS Accelerometer with Analog Input# ADXL105AQC Technical Documentation
*Manufacturer: Analog Devices Inc. (ADI)*
## 1. Application Scenarios
### Typical Use Cases
The ADXL105AQC is a high-performance, single-axis accelerometer designed for precision measurement applications requiring high stability and low noise characteristics. This MEMS-based capacitive accelerometer operates on ±5V supplies and provides a full-scale range of ±5g.
Primary Applications:
- Vibration Monitoring : Industrial machinery health monitoring where precise vibration analysis is critical for predictive maintenance
- Tilt Sensing : Platform leveling systems in construction equipment and antenna positioning systems
- Structural Health Monitoring : Bridge, building, and infrastructure monitoring for seismic activity and structural integrity assessment
- Inertial Navigation : Supplemental sensor for attitude reference systems in marine and aerospace applications
### Industry Applications
Industrial Automation
- Machine condition monitoring in manufacturing facilities
- Robotic arm positioning and vibration control
- Conveyor system monitoring and safety interlocks
Aerospace & Defense
- Aircraft structural health monitoring
- Missile guidance systems (supplemental sensing)
- Platform stabilization systems
Transportation
- Railway track condition monitoring
- Vehicle suspension system analysis
- Cargo securement monitoring
Research & Development
- Laboratory instrumentation for motion analysis
- Seismic research equipment
- Vibration testing and characterization
### Practical Advantages and Limitations
Advantages:
- High Resolution : 1.5mg resolution at 10Hz bandwidth enables precise low-level vibration detection
- Low Noise Density : 500μg/√Hz typical noise density provides excellent signal-to-noise ratio
- Temperature Stability : ±0.5% full-scale range over temperature ensures consistent performance
- Robust Construction : Survives 2000g shock for reliable operation in harsh environments
- Analog Output : Simplifies interface with data acquisition systems and microcontrollers
Limitations:
- Single-Axis Operation : Requires multiple units for multi-axis measurements, increasing system complexity
- Limited Dynamic Range : ±5g range may be insufficient for high-shock applications
- Analog Interface : Requires external ADC for digital systems, adding conversion complexity
- Temperature Compensation : May require external compensation circuits for highest accuracy applications
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Power Supply Issues
- Pitfall : Using noisy or unstable power supplies causing measurement inaccuracies
- Solution : Implement proper decoupling with 0.1μF ceramic capacitors close to power pins and additional 10μF tantalum capacitors
Grounding Problems
- Pitfall : Poor ground return paths introducing noise and offset errors
- Solution : Use star grounding technique with separate analog and digital ground planes
Mechanical Mounting
- Pitfall : Improper mechanical coupling affecting frequency response and introducing mounting strain
- Solution : Use recommended mounting torque (typically 2-3 in-lbs) and ensure flat, clean mounting surfaces
### Compatibility Issues with Other Components
ADC Interface Considerations
- The analog output requires careful matching with ADC specifications:
- Ensure ADC input range matches the ±2.5V output swing (with 2.5V offset)
- Consider anti-aliasing filters based on ADC sampling rate
- Match ADC resolution to the accelerometer's 1.5mg resolution requirement
Microcontroller Integration
- Voltage Level Matching : Ensure microcontroller ADC can handle the 0-5V output range
- Sampling Rate : Minimum sampling rate should be 2× the highest frequency of interest
- Digital Isolation : When interfacing with digital systems, consider opto-isolators for noise immunity
Signal Conditioning
- Filter Requirements : Built-in 3-pole low-pass filter at 5kHz, but additional filtering may be needed for
