SNAS856A September   2024  – March 2025 REF80

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Thermal Information
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Heater
      2. 7.3.2 Buried Zener Reference
  9. 8 Parameter Measurement Information
    1. 8.1 Long-Term Stability
    2. 8.2 Temperature Drift
    3. 8.3 Thermal Hysteresis
    4. 8.4 Noise Performance
      1. 8.4.1 1/f Noise
      2. 8.4.2 Broadband Noise
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical Application: Basic Voltage Reference Connection
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Typical Application Circuits
        1. 9.2.2.1 Precision Voltage Divider Connection
        2. 9.2.2.2 Calibration Signal
    3. 9.3 Power Supply Recommendation
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.2 Temperature Drift

The REF80 has integrated on chip heater, which is factory programmed to TSET = 115°C temperature. Heater regulates the TSET temperature to ±1°C for entire operating temperature range. This results in 0.05ppm/°C temperature drift coefficient for REF80. Figure 6-2 shows temperature drift profile of 42 devices.

The temperature coefficient is calculated using the box method in which a box is formed by the min/max variation for the nominal output voltage over the operating temperature range. REF80 has a maximum temperature coefficient of 0.2ppm/°C for 0°C to70°C temperature range. The box method specifies limits for the temperature error but does not specify the exact shape and slope of the device under test. See SLYT183 for more information on the box method. The box method equation is shown in Equation 2:

Equation 2. D r i f t ( p p m / ° C )   =   V R E F ( M A X ) - V R E F ( M I N ) V R E F ( 25 ° C ) ×   T e m p e r a t u r e   R a n g e × 10 6
REF80 Temperature Drift Distribution Figure 8-3 Temperature Drift Distribution