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

12.1 Layout Guidelines

For optimal performance of this design, follow standard printed circuit board (PCB) layout guidelines, including proper decoupling close to all integrated circuits and adequate power and ground connections with large copper pours. Select a PCB size with connectors that connect directly to the MSP430 LaunchPad™.

Figure 25 shows an example of a PCB layout for a data acquisition system using the REF33xx.

Some key considerations are:

  • Connect a low-ESR, 1-μF ceramic capacitor at the IN pin for bypass, and a 0.1-µF to 10-µF ceramic capacitor at the OUT pin for stability of the REF33xx.
  • Decouple other active devices in the system per the device specifications.
  • Use a solid ground plane helps distribute heat and reduces EMI noise pickup.
  • Place the external components as close to the device as possible. This configuration prevents parasitic errors (such as the Seebeck effect) from occurring.
  • Minimize trace length between the reference and bias connections to the ADC to reduce noise pickup.
  • Do not run sensitive analog traces in parallel with digital traces. Avoid crossing digital and analog traces if possible, and only make perpendicular crossings when absolutely necessary.