ADS1115IDGST: 16-Bit Sigma-Delta ADC with I2C Interface | Texas Instruments
ADS1115IDGST: Ultra-Precise 16-Bit Sigma-Delta ADC with I2C Interface from Texas Instruments
The ADS1115IDGST represents the pinnacle of analog-to-digital conversion technology from Texas Instruments, offering engineers and designers an exceptional combination of precision, flexibility, and power efficiency in a compact surface-mount package. This comprehensive guide explores every aspect of this remarkable 16-bit ADC to help you maximize its potential in your next design project.
Unparalleled Performance in Data Acquisition
Advanced Sigma-Delta Architecture
The ADS1115IDGST employs a sophisticated sigma-delta modulation technique that delivers true 16-bit resolution without missing codes. This architecture provides excellent noise rejection (common-mode rejection ratio of 105dB at 50Hz) and outstanding linearity ( 0.01% typical), making it particularly suitable for:
- High-precision industrial sensor interfaces
- Medical instrumentation requiring FDA-grade accuracy
- Scientific measurement equipment
- Audio signal processing applications
Programmable Gain Amplifier (PGA)
The integrated PGA offers selectable gains of 6.144V, 4.096V, 2.048V, 1.024V, 0.512V, 0.256V, allowing direct connection to low-voltage sensors without external amplification. This feature significantly reduces BOM cost and PCB space while improving signal integrity.
Technical Specifications Deep Dive
Conversion Performance
| Parameter | Value |
|---|---|
| Resolution | 16 bits (no missing codes) |
| Sampling Rate | 8SPS to 860SPS (programmable) |
| INL (Integral Non-Linearity) | 0.01% of FSR (max) |
| Noise Performance | 0.15 Vrms at 8SPS (PGA=8) |
Flexible Input Configuration
The device supports multiple operating modes:
- 4-channel differential mode for noise-critical applications
- 2-channel single-ended mode for simpler designs
- Continuous conversion or single-shot mode (reducing power to 0.5 A when idle)
Design Advantages
Simplified System Integration
The I2C-compatible interface (supporting standard, fast, and high-speed modes up to 3.4MHz) simplifies connection to microcontrollers while minimizing pin count. Four programmable I2C addresses allow multiple devices on the same bus.
Power Management Features
- Ultra-low power consumption: 150 A during active conversion
- Wide supply range: 2.0V to 5.5V (compatible with 3.3V and 5V systems)
- Automatic power-down between conversions
Application Spotlight
Industrial Automation
In factory automation systems, the ADS1115IDGST excels at:
- 4-20mA current loop monitoring
- PLC analog input modules
- Motor control feedback systems
IoT and Wearable Devices
The combination of small size (3mm 3mm VSSOP package) and low power makes it ideal for:
- Battery-powered sensor nodes
- Environmental monitoring stations
- Wearable health monitors
Design Considerations
PCB Layout Recommendations
For optimal performance:
- Use a solid ground plane under the device
- Place bypass capacitors (0.1 F ceramic + 10 F tantalum) within 5mm of VDD
- Route analog inputs away from digital traces
- Consider using the integrated programmable comparator for threshold detection
Comparison to Competing ADCs
When benchmarked against similar 16-bit ADCs, the ADS1115IDGST offers:
- 30% lower power consumption than competing devices
- Integrated features (PGA, reference, oscillator) reducing external components
- Smaller package size compared to QFN alternatives
Purchasing and Support
Texas Instruments provides comprehensive support including:
- Reference designs (SBAS503)
- Evaluation modules (ADS1115EVM)
- SPICE models for simulation
- Detailed application notes on noise reduction techniques
For volume production, the ADS1115IDGST is available in tape-and-reel packaging (2500 units per reel) with standard lead times of 6-8 weeks. Contact our authorized distributors for pricing tiers and sample requests.
Future-Proof Your Designs
With its industry-leading combination of precision, flexibility, and ease-of-use, the ADS1115IDGST from Texas Instruments represents the optimal choice for designers looking to implement high-performance data acquisition in space-constrained applications. Its active status in TI's product lineup ensures long-term availability and support for your mission-critical designs.