SNVSCN7C November   2023  – May 2025 REF54

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  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics REF54250
    6. 6.6  Electrical Characteristics REF54300
    7. 6.7  Electrical Characteristics REF54410
    8. 6.8  Electrical Characteristics REF54450
    9. 6.9  Electrical Characteristics REF54500
    10. 6.10 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Temperature Drift
    2. 7.2 Long-Term Stability
    3. 7.3 Noise Performance
      1. 7.3.1 1/f Noise
      2. 7.3.2 Broadband Noise
    4. 7.4 Thermal Hysteresis
    5. 7.5 Solder Heat Shift
    6. 7.6 Power Dissipation
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 EN Pin
      2. 8.3.2 NR Pin
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 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 Curves
      2. 9.2.2 Reference Attach With High Precision ADC
    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

7.3.2 Broadband Noise

Broadband noise or white noise is flat over the whole spectrum which is restricted by the bandwidth of internal bandgap reference. The broadband noise is measured by high-pass filtering the output of the REF54 and measuring the result on a precision spectrum analyzer as shown in Figure 7-9. The DC component of the REF54 is removed by using a high-pass filter and then amplified. Two stages of small gain has been used to maximize the noise bandwidth analysis.
REF54 Broadband Noise Test Setup Figure 7-9 Broadband Noise Test Setup

Figure 7-10 shows the typical white noise floor for REF54. Designer can use NR pin to restrict the noise bandwidth to achieve required resolution for the signal chain. Connecting 1μF at NR pin creates a typical low pass filter of 12Hz for the band gap noise which reduces the white noise floor of REF54. Capacitor > 1μF eliminates all the noise in > 10Hz band.

REF54 Noise Performance 10Hz to 100kHz (CNR = Open)Figure 7-10 Noise Performance 10Hz to 100kHz (CNR = Open)
REF54 Noise Performance 10Hz to 100kHz (COUT) = 10μFFigure 7-11 Noise Performance 10Hz to 100kHz (COUT) = 10μF