Self-Calibrating/ 16-Bit ANALOG-TO-DIGITAL CONVERTER# ADS1100 Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The ADS1100 is a precision, continuously self-calibrating Analog-to-Digital Converter (ADC) with 16-bit resolution and an I²C interface, making it ideal for various measurement applications:
Primary Use Cases:
- Industrial Process Control : Monitoring temperature, pressure, and flow sensors in manufacturing environments
- Battery Monitoring Systems : Precise voltage and current measurement in portable devices and energy storage systems
- Medical Instrumentation : Patient monitoring equipment requiring high-precision analog measurements
- Environmental Monitoring : Air quality sensors, weather stations, and pollution detection systems
- Automotive Sensing : Engine control units, battery management, and sensor interfaces
### Industry Applications
Industrial Automation
- Advantages : Excellent noise immunity in electrically noisy environments, wide operating temperature range (-40°C to +125°C)
- Limitations : Limited to single-ended inputs, requiring external multiplexers for multi-channel applications
- Implementation : Direct interface with 4-20mA current loop sensors and RTD temperature sensors
Consumer Electronics
- Advantages : Low power consumption (continuous conversion: 180µA, single-shot: 1µA) ideal for battery-powered devices
- Limitations : Maximum sample rate of 128SPS may be insufficient for high-speed audio applications
- Implementation : Smart home sensors, wearable health monitors, and portable test equipment
Medical Devices
- Advantages : High accuracy (0.0125% FSR INL) suitable for critical medical measurements
- Limitations : Requires careful PCB layout and shielding for medical-grade EMI compliance
- Implementation : Blood pressure monitors, glucose meters, and patient vital signs monitoring
### Practical Advantages and Limitations
Key Advantages:
- Self-Calibration : Continuous background calibration eliminates offset and gain errors
- High Resolution : 16-bit no missing codes ensures precise measurements
- Flexible Supply : Operates from 2.7V to 5.5V single supply
- Small Package : Available in SOT23-6 package for space-constrained applications
Notable Limitations:
- Single-Ended Input : Limited to single-channel operation without external components
- Sample Rate : Maximum 128 samples/second restricts high-speed applications
- I²C Only : Lack of SPI interface may limit compatibility with some microcontrollers
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Power Supply Issues
- Pitfall : Noise coupling from digital supply to analog circuitry
- Solution : Implement separate analog and digital power planes with proper decoupling
- Implementation : Use 10µF tantalum capacitor and 0.1µF ceramic capacitor close to VDD pin
Grounding Problems
- Pitfall : Single ground point creating ground loops
- Solution : Star grounding configuration with separate analog and digital ground planes
- Implementation : Connect analog and digital grounds at ADC power supply entry point
Signal Integrity
- Pitfall : Long analog trace lengths introducing noise
- Solution : Keep analog input traces short and use proper shielding
- Implementation : Route analog signals away from digital lines and clock signals
### Compatibility Issues with Other Components
Microcontroller Interface
- I²C Compatibility : Works with standard 100kHz and 400kHz I²C buses
- Voltage Level Matching : Ensure VDD matches microcontroller logic levels (2.7V-5.5V range)
- Pull-up Resistors : Required on SDA and SCL lines (typical 4.7kΩ for 3.3V, 2.2kΩ for 5V)
Sensor Compatibility
- Input Range : Compatible with sensors outputting 0V to
