Industrial Sensor Interface Solution

Application

Description

Complete sensor interface solution for industrial temperature, pressure, and strain measurement applications with high accuracy and reliability.

Core Advantages

High-precision 24-bit ADC with noise-free resolution
Automatic lead compensation for RTD measurements
Wide input voltage range for industrial systems
Complete BOM with isolation options
Robust EMI protection for harsh environments

Recommended Bill of Materials (BOM)

Item Part Number Description Quantity Datasheet
1 AU6020 24-bit RTD-to-digital converter 1 📄 Download
2 AU8110 3A buck converter for sensor power 1 📄 Download
3 Pt100 Platinum RTD temperature sensor 1 📄 Download
4 10µH Inductor Power inductor for buck converter 1 📄 Download
5 10µF Ceramic Input/output capacitors 4 📄 Download

Applications

Industrial Temperature Monitoring
Process Control Systems
HVAC Equipment
Building Automation
Environmental Monitoring

Technical Specifications

Temperature Accuracy
±0.1°C (Pt100)
Resolution
24-bit (0.001°C)
Input Voltage
18V to 36V (24V nominal)
Output Current
100mA for sensor and interface
Isolation
Optional 2.5kV galvanic isolation
Operating Temperature
-40°C to +85°C

Customer Success Stories

Industrial Automation Company

Manufacturing | Process Temperature Monitoring

Challenge

Required accurate temperature measurement in noisy industrial environment

Solution

Implemented AU6020 with proper filtering and isolation

Results

HVAC Systems Manufacturer

Building Automation | Building Temperature Control

Challenge

Needed cost-effective multi-channel temperature sensing

Solution

Used multiple AU6020 devices with shared SPI bus

Results

FAE Expert Insights

S

Senior FAE

Applications Engineer

10+ years

Professional Insights

In my experience with industrial sensor applications, the sensor interface is often the weakest link in the measurement chain. The Aurasemi AU6020 provides excellent performance for RTD measurements with proper design. Key considerations include: input filtering to reject EMI, proper PCB layout to minimize noise, and calibration for highest accuracy. For thermocouple applications, the cold junction compensation accuracy is critical - the AU6030's integrated CJC works well when the device is placed close to the connection point. I always recommend using 3-wire or 4-wire configurations for RTDs to eliminate lead resistance errors. For industrial environments, don't forget protection circuits - TVS diodes and series resistors can save your system from field wiring faults.

Key Takeaways

  • Use proper input filtering for EMI rejection
  • Place CJC device close to thermocouple connection
  • Implement 3-wire or 4-wire RTD configurations
  • Add protection circuits for industrial environments

Decision Framework

Steps:
  1. Define required measurement accuracy and temperature range
  2. Select RTD or thermocouple based on application requirements
  3. Design input filtering and protection circuits
  4. Implement proper PCB layout and grounding
  5. Perform system calibration at operating temperature

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Frequently Asked Questions

What is the total solution cost?

The industrial sensor interface solution BOM cost includes: (1) AU6020 RTD converter - approximately $3-4

(2) AU8110 buck converter - approximately $2-3

(3) Passive components - approximately $1-2

(4) RTD sensor - varies by type and quality ($5-50). Total solution cost is $10-15 in volume, significantly lower than discrete implementations or competing integrated solutions. Contact LiTong sales for specific pricing based on your volume requirements.

Total solution cost $10-15; contact LiTong for volume pricing.

How do I achieve galvanic isolation?

Galvanic isolation for industrial sensor interfaces: (1) Power isolation - use isolated DC-DC converter or isolated buck

(2) Signal isolation - use digital isolators for SPI interface

(3) Sensor isolation - use isolated RTD transmitter for hazardous areas

(4) Isolation rating - typically 2.5kV for industrial, 5kV for medical. The AU6020's SPI interface makes digital isolation straightforward. For complete isolation, consider the AU6020-ISOL variant with integrated isolation. Contact LiTong FAE for isolated design recommendations.

Use digital isolators for SPI and isolated power supply for galvanic isolation.

How do I protect against field wiring faults?

Industrial sensor interfaces require protection against field wiring faults: (1) Overvoltage protection - use TVS diodes to clamp transients

(2) Overcurrent protection - series resistors limit fault current

(3) ESD protection - protect against electrostatic discharge

(4) Isolation - galvanic isolation for safety-critical applications

(5) Filtering - RC filters reject high-frequency noise. For RTD inputs, use 100Ω series resistors and TVS diodes rated for your maximum expected voltage. Place protection components close to the connector. The AU6020 includes internal ESD protection, but external protection is recommended for harsh environments.

Implement TVS diodes, series resistors, and filtering for robust protection.

What cable type should I use for sensors?

Sensor cable selection affects measurement accuracy: (1) RTD cables - use low-resistance copper cable, 3-wire or 4-wire configuration

(2) Thermocouple cables - use matched extension cable same type as TC

(3) Shielding - use shielded cable in EMI environments

(4) Twisted pair - reduces magnetic interference

(5) Insulation - rated for operating temperature. For RTDs, 22-24 AWG wire is typical. Keep cable length as short as practical - long cables increase noise pickup and resistance errors. For very long runs, consider using transmitters at the sensor location.

Use matched TC extension cable or low-resistance copper for RTDs; shield in EMI environments.

How often should I calibrate the system?

Calibration frequency depends on accuracy requirements and operating conditions: (1) Initial calibration - always perform before first use

(2) Periodic calibration - annually for most industrial applications

(3) Critical applications - quarterly or monthly for highest accuracy

(4) After maintenance - recalibrate after sensor replacement

(5) Temperature cycling - consider more frequent calibration if wide temperature swings. The AU6020 has excellent long-term stability, but sensor drift may require more frequent calibration. Document calibration results to track drift over time. Use certified reference standards for calibration.

Annual calibration for typical applications; quarterly for critical measurements.