SNIS244 September   2025 ISOTMP35R

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Insulation Specification
    6. 5.6  Power Ratings
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics
    10. 5.10 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Features Description
      1. 6.3.1 Integrated Isolation Barrier and Thermal Response
      2. 6.3.2 Analog Output
        1. 6.3.2.1 Output Accuracy
        2. 6.3.2.2 Drive Capability
        3. 6.3.2.3 Common Mode Transient Immunity (CMTI)
      3. 6.3.3 Thermal Response
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 External Buffer
      2. 7.1.2 ADC Interface Considerations
      3. 7.1.3 Electromagnetic Noise Mitigation
        1. 7.1.3.1 Filtering Techniques
        2. 7.1.3.2 General Design Guidelines
        3. 7.1.3.3 PCB Layout Practices
      4. 7.1.4 Insulation Lifetime
    2. 7.2 Power Supply Recommendations
      1. 7.2.1 PSRR Considerations
    3. 7.3 Layout
      1. 7.3.1 Layout Guidelines
      2. 7.3.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
  • DFP|12
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1.2 ADC Interface Considerations

The ISOTMP35R device provides an analog voltage output (VOUT) that can be digitized using an external analog-to-digital converter (ADC). To ensure accurate temperature measurements, TI recommends using an ADC with at least 12-bit resolution. With a 2.5V reference, a 12-bit ADC provides an LSB of approximately 0.61mV, corresponding to a temperature resolution of 0.061°C per LSB. This resolution is sufficient for most applications requiring precise temperature monitoring.

When interfacing the ISOTMP35R device with an ADC, additional circuitry is recommended to ensure signal integrity:

  • CLOAD capacitor: Stabilizes VOUT and reduces ripples caused by high-voltage transients across the isolation barrier, and should be placed close to the ISOTMP35R VOUT pin.
  • RC filter (RFILTER, CFILTER): Suppresses noise on the VOUT line and should be placed close to the ADC input.
  • CFILTER capacitor: Also acts as a charge reservoir to mitigate voltage glitches during ADC sampling.

Figure 7-2 illustrates a recommended circuit for connecting the ISOTMP35R output to an ADC. This configuration ensures accurate digitization of the ISOTMP35R output with minimal noise and transient effects.

ISOTMP35R Connecting the ISOTMP35R Output to an ADC Figure 7-2 Connecting the ISOTMP35R Output to an ADC