JAJSJG5 July   2020 ADS9226

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Timing Diagrams
    9. 6.9 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Converter Modules
        1. 7.3.1.1 Analog Input With Sample-and-Hold
        2. 7.3.1.2 ADC Transfer Function
      2. 7.3.2 External Reference Voltage
      3. 7.3.3 Reference Buffers
    4. 7.4 Device Functional Modes
      1. 7.4.1 ACQ State
      2. 7.4.2 CNV State
      3. 7.4.3 Output Data Word
      4. 7.4.4 Conversion Control and Data Transfer Frame
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 ADC Input Driver
        1. 8.1.1.1 Charge-Kickback Filter
      2. 8.1.2 Input Amplifier Selection
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Signal Path
      2. 10.1.2 Grounding and PCB Stack-Up
      3. 10.1.3 Decoupling of Power Supplies
      4. 10.1.4 Reference Decoupling
      5. 10.1.5 Analog Input Decoupling
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 サポート・リソース
    4. 11.4 Trademarks
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 用語集
  12. 12Mechanical, 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

7.3.3 Reference Buffers

On the CS rising edge, both converters start converting the sampled value on the analog input, and the internal capacitors are switched to the REFP_x pins. Most of the switching charge required during the conversion process is provided by the external decoupling capacitor CREFP_x. If the charge lost from CREFP_x is not replenished before the next CS rising edge, the subsequent conversion occurs with this different reference voltage and causes a proportional error in the output code. To eliminate these errors, the internal reference buffers of the device maintains the voltage on the REFP_x pins.

All performance characteristics of the device are specified with the internal reference buffer and a specified value of CREFP_x. As shown in Figure 7-4, place a decoupling capacitor CREFP_x between the REFP_x pins and the REFM_x pin as close to the device as possible.