SBOS392H August   2007  – August 2019 REF3312 , REF3318 , REF3320 , REF3325 , REF3330 , REF3333

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      REF3312 in a Single-Supply Signal Chain
      2.      Dropout Voltage vs Load Current
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
    1. Table 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. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Thermal Hysteresis
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Start-Up Time
      2. 9.3.2 Low Temperature Drift
      3. 9.3.3 Power Dissipation
      4. 9.3.4 Noise Performance
    4. 9.4 Device Functional Modes
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 REF3312 in a Bipolar Signal-Chain Configuration
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Op Amp Level-Shift Design
          2. 10.2.1.2.2 Differential Input Attenuator Design
          3. 10.2.1.2.3 Input Filtering
          4. 10.2.1.2.4 Component Selection
            1. 10.2.1.2.4.1 Voltage References
            2. 10.2.1.2.4.2 Op Amp
          5. 10.2.1.2.5 Input Attenuation and Level Shifting
          6. 10.2.1.2.6 Input Filtering
          7. 10.2.1.2.7 Passive Component Tolerances and Materials
        3. 10.2.1.3 Application Curves
          1. 10.2.1.3.1 DC Performance
          2. 10.2.1.3.2 AC Performance
  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 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.1.2.2 Differential Input Attenuator Design

VDIFF is the difference between the two inputs, as shown in Equation 8:

Equation 8. REF3312 REF3318 REF3320 REF3325 REF3330 REF3333 q_vdiff_sbos392.gif

When the ratio of R3 and R2 equals the ratio of R7 and R6, Equation 8 simplifies to Equation 10.

That is, if:

Equation 9. REF3312 REF3318 REF3320 REF3325 REF3330 REF3333 q_r3_vref_sbos392.gif

Then:

Equation 10. REF3312 REF3318 REF3320 REF3325 REF3330 REF3333 q_vdiff_2_sbos392.gif

Determine the ratio of R1, R2, and R3 by setting A1+ equal to the maximum VDIFF for a full-scale positive or negative input voltage, VIN_MAX, as shown in Equation 11:

Equation 11. REF3312 REF3318 REF3320 REF3325 REF3330 REF3333 q_a1_plus_vdiff_max_sbos392.gif

R2 equals R3; therefore, Equation 11 simplifies to R2 / 2, resulting in Equation 12:

Equation 12. REF3312 REF3318 REF3320 REF3325 REF3330 REF3333 q_vdiff_max_sbos392.gif