SBAS804F September   2017  – June 2021 REF3425 , REF3430 , REF3433 , REF3440 , REF3450

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Solder Heat Shift
    2. 8.2 Long-Term Stability
    3. 8.3 Thermal Hysteresis
    4. 8.4 Power Dissipation
    5. 8.5 Noise Performance
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Supply Voltage
      2. 9.3.2 Low Temperature Drift
      3. 9.3.3 Load Current
    4. 9.4 Device Functional Modes
      1. 9.4.1 EN Pin
      2. 9.4.2 Negative Reference Voltage
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application: Basic Voltage Reference Connection
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Input and Output Capacitors
        2. 10.2.2.2 4-Wire Kelvin Connections
        3. 10.2.2.3 VIN Slew Rate Considerations
        4. 10.2.2.4 Shutdown/Enable Feature
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

8.3 Thermal Hysteresis

Thermal hysteresis is measured with the REF34xx soldered to a PCB, similar to a real-world application. Thermal hysteresis for the device is defined as the change in output voltage after operating the device at 25°C, cycling the device through the specified temperature range, and returning to 25°C. The PCB was baked at 150°C for 30 minutes before thermal hysteresis was measured. Hysteresis can be expressed by Equation 1:

Equation 1. GUID-3D4CA857-39BB-4446-A74A-EC85DD7ABA6A-low.gif

where

  • VHYST = thermal hysteresis (in units of ppm)
  • VNOM = the specified output voltage
  • VPRE = output voltage measured at 25°C pre-temperature cycling
  • VPOST = output voltage measured after the device has cycled from 25°C through the specified temperature range of –40°C to +125°C and returns to 25°C.

Typical thermal hysteresis distribution is as shown in Figure 8-4 and Figure 8-5.

GUID-98196DCE-CE9C-4726-9CE9-CB4F47A0E85C-low.gifFigure 8-4 Thermal Hysteresis Distribution Cycle 1 (VOUT)
GUID-D8635073-378E-4EBC-B691-D72930666755-low.gif Figure 8-5 Thermal Hysteresis Distribution Cycle 2 (VOUT)