JAJSH03B May   2013  – February 2019 ADS8860

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      ADC 電源用に別個の LDO が不要
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements: 3-Wire Operation
    7. 8.7 Timing Requirements: 4-Wire Operation
    8. 8.8 Timing Requirements: Daisy-Chain
    9. 8.9 Typical Characteristics
  9. 9 Parameter Measurement Information
    1. 9.1 Equivalent Circuits
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1 Analog Input
      2. 10.3.2 Reference
      3. 10.3.3 Clock
      4. 10.3.4 ADC Transfer Function
    4. 10.4 Device Functional Modes
      1. 10.4.1 CS Mode
        1. 10.4.1.1 3-Wire CS Mode Without a Busy Indicator
        2. 10.4.1.2 3-Wire CS Mode With a Busy Indicator
        3. 10.4.1.3 4-Wire CS Mode Without a Busy Indicator
        4. 10.4.1.4 4-Wire CS Mode With a Busy Indicator
      2. 10.4.2 Daisy-Chain Mode
        1. 10.4.2.1 Daisy-Chain Mode Without a Busy Indicator
        2. 10.4.2.2 Daisy-Chain Mode With a Busy Indicator
  11. 11Application and Implementation
    1. 11.1 Application Information
      1. 11.1.1 ADC Reference Driver
      2. 11.1.2 ADC Input Driver
        1. 11.1.2.1 Input Amplifier Selection
        2. 11.1.2.2 Charge-Kickback Filter
    2. 11.2 Typical Applications
      1. 11.2.1 DAQ Circuit for a 1-µs, Full-Scale Step Response
        1. 11.2.1.1 Design Requirements
        2. 11.2.1.2 Detailed Design Procedure
      2. 11.2.2 DAQ Circuit for Lowest Distortion and Noise Performance at 1 MSPS
        1. 11.2.2.1 Design Requirements
        2. 11.2.2.2 Detailed Design Procedure
      3. 11.2.3 Ultralow-Power DAQ Circuit at 10 kSPS
        1. 11.2.3.1 Design Requirements
        2. 11.2.3.2 Detailed Design Procedure
  12. 12Power Supply Recommendations
    1. 12.1 Power-Supply Decoupling
    2. 12.2 Power Saving
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  14. 14デバイスおよびドキュメントのサポート
    1. 14.1 ドキュメントのサポート
      1. 14.1.1 関連資料
    2. 14.2 ドキュメントの更新通知を受け取る方法
    3. 14.3 コミュニティ・リソース
    4. 14.4 商標
    5. 14.5 静電気放電に関する注意事項
    6. 14.6 Glossary
  15. 15メカニカル、パッケージ、および注文情報

12.2 Power Saving

The device has an auto power-down feature that powers down the internal circuitry at the end of every conversion. Referring to Figure 67, the input signal is acquired on the sampling capacitors when the device is in a power-down state (tacq); at the same time, the result for the previous conversion is available for reading. The device powers up on the start of the next conversion. During conversion phase (tconv), the device also consumes current from the reference source (connected to the REF pin).

ADS8860 power_scaling_illustration.gifFigure 67. Power Scaling With Throughput

The conversion time, tconv, is independent of the SCLK frequency. When operating the device at speeds lower than the maximum rated throughput, the conversion time, tconv, does not change; the device spends more time in power-down state. Therefore, as shown in Figure 68, the device power consumption from the AVDD supply and the external reference source is directly proportional to the speed of operation. Extremely low AVDD power-down current (50 nA, typical) and extremely low external reference leakage current (250 nA, typical), make this device ideal for very low throughput applications (such as pulsed measurements).

ADS8860 C031_SBAS547.pngFigure 68. Power Scaling With Throughput