CA-IS1301
Isolated ADC optimized for temperature sensor interfaces with RTD and thermocouple support
Product Overview
Description
CA-IS1301 is a specialized isolated ADC designed for temperature measurement applications. The device supports RTD (PT100/PT1000) and thermocouple inputs with built-in excitation and cold junction compensation.
With 5kVrms isolation and 20-bit effective resolution, this ADC provides accurate temperature measurements in industrial process control applications.
The integrated sensor excitation and linearization simplify temperature sensor interface design.
Product Series
CA
Primary Application
Industrial temperature control
Key Features
- Optimized for temperature sensors
- RTD and thermocouple support
- Built-in sensor excitation
- Cold junction compensation
- 5kVrms reinforced isolation
- 20-bit effective resolution
- Linearization for common sensors
- SPI interface
Specifications
| Resolution | 20-bit effective |
|---|---|
| Sample Rate | Up to 10kSPS |
| Isolation Voltage | 5kVrms (reinforced) |
| Sensor Types | RTD, Thermocouple |
| Excitation Current | 100μA to 1mA |
| Accuracy | ±0.1°C for RTD |
| CJC Accuracy | ±0.5°C |
| Package | SOIC-20 |
Applications
Industrial temperature control
Industrial automation and control
Process monitoring
Electronic system design
HVAC systems
Electronic system design
Food processing
Electronic system design
Medical equipment
Medical electronics
Laboratory equipment
Electronic system design
Energy monitoring
Renewable energy systems
FAE Expert Insights
"CA-IS1301 is purpose-built for temperature measurement applications. The integrated excitation and cold junction compensation save significant design effort compared to discrete solutions. I've used this ADC in industrial process control systems with PT100 sensors, achieving excellent accuracy. The linearization for common sensor types eliminates the need for lookup tables in software. The 5kVrms isolation is crucial for high-voltage industrial environments. For best accuracy, follow the recommended PCB layout for the sensor connections and use proper shielding."
Integrated temperature sensor interface with 5kVrms isolation
— Dr. Chen Wei, BeiLuo
Frequently Asked Questions
What types of temperature sensors does CA-IS1301 support?
CA-IS1301 supports multiple temperature sensor types: RTDs (PT100, PT1000, PT500) with 2, 3, or 4-wire configurations; Thermocouples (J, K, T, E, N, S, R, B types) with cold junction compensation; Thermistors (NTC and PTC); and Other resistive temperature sensors. The device provides configurable excitation current and gain settings to optimize for each sensor type. Built-in linearization tables for common sensors simplify software development.
Select sensor type in configuration. Contact our FAE team for sensor interface design.
How accurate is the cold junction compensation?
CA-IS1301's integrated cold junction compensation (CJC) for thermocouples has typical accuracy of ±0.5°C over the operating temperature range. The CJC uses an internal temperature sensor located near the thermocouple connection terminals. For highest accuracy: Keep thermocouple connection terminals at uniform temperature; Minimize thermal gradients near terminals; and Consider external CJC for extreme accuracy requirements. The ±0.5°C CJC accuracy is adequate for most industrial applications with standard thermocouple types.
Integrated CJC is adequate for most applications. Contact our FAE team for high-accuracy CJC options.
What is lead compensation for RTD measurements?
Lead compensation eliminates errors from lead wire resistance in RTD measurements. CA-IS1301 supports 2-wire, 3-wire, and 4-wire RTD configurations: 2-wire: No compensation, includes lead resistance in measurement; 3-wire: Compensates for lead resistance assuming equal lead lengths; 4-wire: Kelvin connection eliminates lead resistance completely. For 3-wire configuration, the device measures lead resistance and subtracts it from the measurement. 4-wire provides highest accuracy but requires more wiring. 3-wire offers good accuracy with reasonable wiring complexity.
Use 3-wire for most applications. Use 4-wire for highest accuracy. Contact our FAE team for RTD connection guidance.
How do I convert ADC readings to temperature?
CA-IS1301 provides ADC readings that need conversion to temperature. For RTDs: Use Callendar-Van Dusen equation or lookup table; Device provides resistance value directly; Calculate temperature from resistance. For thermocouples: Use NIST polynomial coefficients or lookup table; Device provides voltage with CJC applied; Calculate temperature from voltage. The device includes built-in linearization for common sensors, providing direct temperature output in some modes. Software libraries are available to simplify conversion.
Use built-in linearization or software conversion. Contact our FAE team for conversion software.
What update rate can I achieve for temperature monitoring?
CA-IS1301 supports temperature update rates up to 10kSPS, but practical rates are lower due to sensor settling time. Typical update rates: Fast monitoring: 10-100 samples/second; Standard process control: 1-10 samples/second; Slow processes: 0.1-1 samples/second. Temperature sensors have thermal mass that limits how fast temperature changes can be measured. For most industrial processes, 1-10 samples/second provides adequate response. Higher rates may be needed for fast thermal control loops.
Select update rate based on process dynamics. Contact our FAE team for sampling strategy.
Can CA-IS1301 measure multiple temperature sensors?
CA-IS1301 supports single sensor measurement per device. For multiple sensors, options include: Using multiple CA-IS1301 devices (one per sensor); Using external multiplexer with single CA-IS1301; or Using CA-IS1300 for multiplexed applications. Each CA-IS1301 provides isolated measurement for one sensor. For systems with multiple sensors, consider the trade-off between: Multiple isolated ADCs (higher cost, simpler design); or Multiplexed single ADC (lower cost, more complex). For critical measurements, individual isolation per sensor provides best reliability.
Use multiple devices for critical measurements. Contact our FAE team for multi-sensor solutions.