JAJSNM7 December   2021 REF35

ADVANCE INFORMATION  

  1. 特長
  2. アプリケーション
  3. 説明
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  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. Parameter Measurement Information
    1. 8.1 Solder Heat Shift
    2. 8.2 Temperature Coefficient
    3. 8.3 Long-Term Stability
    4. 8.4 Thermal Hysteresis
    5. 8.5 Noise Performance
      1. 8.5.1 Low Frequency (1/f) Noise
      2. 8.5.2 Broadband Noise
    6. 8.6 Power Dissipation
  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 EN Pin
      3. 9.3.3 NR Pin
    4. 9.4 Device Functional Modes
      1. 9.4.1 Basic Connections
      2. 9.4.2 スタートアップ
      3. 9.4.3 出力過渡動作
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application: Negative Reference Voltage
    3. 10.3 Typical Application: Precision Power Supply and Reference
      1. 10.3.1 Design Requirements
      2. 10.3.2 Detailed Design Procedure
        1. 10.3.2.1 リファレンスの選択
        2. 10.3.2.2 Input and Output Capacitors
        3. 10.3.2.3 Selection of ADC
      3. 10.3.3 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 サポート・リソース
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

Low Frequency (1/f) Noise

Flicker noise, also known as 1/f noise, is a low frequency noise that affects the device output voltage which can affect precision measurements in ADCs. This noise increases proportionally with output voltage and operating temperature. It is measured by filtering the output from 0.1-Hz to 10-Hz. Since the 1/f noise is an extremely low value, the frequency of interest needs to be amplified and band-pass filtered. This is done by using a high-pass filter to block the DC voltage. The resulting noise is then amplified by a gain of 1000. The bandpass filter is created by a series of high-pass and low-pass filter that adds additional gain to make it more visible on a oscilloscope as shown in Figure 8-7. Figure 8-8 shows the effect of flicker noise over 10 second. Flicker noise must be tested in a Faraday cage enclosure to block environmental noise.

GUID-32C95F0F-ABA7-47FB-9BB6-37CAFBCDD9D2-low.gifFigure 8-7 Low Frequency (1/f) Noise Test Setup
GUID-32C95F0F-ABA7-47FB-9BB6-37CAFBCDD9D2-low.gifFigure 8-8 0.1-Hz to 10-Hz Voltage Noise

Figure 8-9 shows the typical 1/f noise (0.1-Hz to 10-Hz) distribution across REF35 devices. REF35 device also offers noise reduction functionality by adding an optional capacitor between NR (pin 5) and ground pins.

Figure 8-10 shows the typical 1/f noise (0.1-Hz to 10-Hz) distribution across REF35 devices with 10 μF capacitor between NR pin and GND.

GUID-32C95F0F-ABA7-47FB-9BB6-37CAFBCDD9D2-low.gifFigure 8-9 0.1-Hz to 10-Hz Noise Distribution (NR = Open)
GUID-32C95F0F-ABA7-47FB-9BB6-37CAFBCDD9D2-low.gifFigure 8-10 0.1-Hz to 10-Hz Noise Distribution (NR = 10 μF)