SNAS794A June   2020  – June 2020 REF4132

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Dropout vs. Current Load Over Temperature
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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. Table 1. Electrical Characteristics
    6. 7.5      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 VIN Slew Rate Considerations
        3. 10.2.2.3 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 Community 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

8.1 Solder Heat Shift

The materials used in the manufacture of the REF4132 have differing coefficients of thermal expansion, resulting in stress on the device die when the part is heated. Mechanical and thermal stress on the device die can cause the output voltages to shift, degrading the initial accuracy specifications of the product. Reflow soldering is a common cause of this error.

In order to illustrate this effect, a total of 32 devices were soldered on two printed circuit boards [16 devices on each printed circuit board (PCB)] using lead-free solder paste and the paste manufacturer suggested reflow profile. The reflow profile is as shown in Figure 15. The printed circuit board is comprised of FR4 material. The board thickness is 1.65 mm and the area is 114 mm × 152 mm.

REF4132 C044_SBOS600.pngFigure 15. Reflow Profile

The reference output voltage is measured before and after the reflow process; the typical shift is displayed in Figure 16. Although all tested units exhibit very low shifts (< 0.01%), higher shifts are also possible depending on the size, thickness, and material of the printed circuit board. An important note is that the histograms display the typical shift for exposure to a single reflow profile. Exposure to multiple reflows, as is common on PCBs with surface-mount components on both sides, causes additional shifts in the output bias voltage. If the PCB is exposed to multiple reflows, the device must be soldered in the last pass to minimize its exposure to thermal stress.

REF4132 G016_REF4132_soldershift.gifFigure 16. Solder Heat Shift Distribution, VREF (%)