JAJSFA9E November   2011  – April 2018 ADS5294

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     ブロック概略図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 デバイス比較表
  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 Dynamic Performance
    6. 8.6  Digital Characteristics
    7. 8.7  Timing Requirements
    8. 8.8  LVDS Timing at Different Sampling Frequencies — 2-Wire Interface, 7x-Serialization, Digital Filter Disabled
    9. 8.9  LVDS Timing at Different Sampling Frequencies — 1-Wire Interface, 14x-Serialization, Digital Filter Disabled
    10. 8.10 Serial Interface Timing Requirements
    11. 8.11 Reset Timing
    12. 8.12 LVDS Timing at Different Sampling Frequencies — 1-Wire Interface, 14x-Serialization, Decimation by 2 Filter Enabled
    13. 8.13 LVDS Timing at Different Sampling Frequencies — 1-Wire Interface, 14x-Serialization, Decimation by 4 Filter Enabled
    14. 8.14 LVDS Timing at Different Sampling Frequencies — 1-Wire Interface, 14x-Serialization, Decimation by 8 Filter Enabled
    15. 8.15 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Analog Input
      2. 9.3.2 Input Clock
      3. 9.3.3 Digital Highpass IIR Filter
      4. 9.3.4 Decimation Filter
      5. 9.3.5 Decimation Filter Equation
        1. 9.3.5.1 Pre-defined Coefficients
        2. 9.3.5.2 Custom Filter Coefficients
      6. 9.3.6 PLL Operation Versus LVDS Timing
        1. 9.3.6.1 Effect on Output Timings
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
        1. 9.5.1.1 Register Initialization
        2. 9.5.1.2 Serial Register Readout
        3. 9.5.1.3 Default States After Reset
    6. 9.6 Register Maps
      1. 9.6.1 Description Of Serial Registers
        1. 9.6.1.1  Power-Down Modes
          1. Table 1. Power-Down Mode Register
        2. 9.6.1.2  Low Frequency Noise Suppression Mode
          1. Table 2. Low Frequency Noise Suppression Mode Register
        3. 9.6.1.3  Analog Input Invert
          1. Table 3. Analog Input Invert Register
        4. 9.6.1.4  LVDS Test Patterns
          1. Table 4. LVDS Test Patterns
        5. 9.6.1.5  Bit-Byte-Word Wise Output
          1. Table 5. Bit-Byte-Word Wise Output
        6. 9.6.1.6  Digital Processing Blocks
        7. 9.6.1.7  Programmable Digital Gain
          1. Table 6. Programmable Digital Gain
        8. 9.6.1.8  Channel Averaging
          1. Table 7. Channel Averaging
        9. 9.6.1.9  Decimation Filter
          1. Table 8. Decimation Filter
        10. 9.6.1.10 Highpass Filter
          1. Table 9. Highpass Filter
        11. 9.6.1.11 Bit-Clock Programmability
          1. Table 10. Bit-Clock Programmability
        12. 9.6.1.12 Output Data Rate Control
          1. Table 11. Output Data Rate Control
        13. 9.6.1.13 Synchronization Pulse
          1. Table 12. Synchronization Pulse
        14. 9.6.1.14 External Reference Mode of Operation
        15. 9.6.1.15 Data Output Format Modes
          1. Table 13. Data Output Format Modes
        16. 9.6.1.16 Programmable Mapping Between Input Channels and Output Pins
          1. Table 14. Mapping Between Input Channels and Output Pins
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Large and Small Signal Input Bandwidth
        2. 10.2.2.2 Drive Circuit
        3. 10.2.2.3 Clock Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイス・サポート
      1. 13.1.1 デバイスの項目表記
        1. 13.1.1.1 仕様の定義
    2. 13.2 ドキュメントのサポート
      1. 13.2.1 関連資料
    3. 13.3 コミュニティ・リソース
    4. 13.4 商標
    5. 13.5 静電気放電に関する注意事項
    6. 13.6 Glossary
  14. 14メカニカル、パッケージ、および注文情報

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

9.3.3 Digital Highpass IIR Filter

DC offset is often observed at ADC input signals. For example, in ultrasound applications, the DC offset from variable-gain amplifier (VGA) varies at different gains. Such a variable offset can introduce artifacts in ultrasound images especially in Doppler modes. Analog filter between ADC and VGA can be used with added noise and power. Digital filter achieves the same performance as analog filters and has more flexibility in fine tuning multiple characteristics.

ADS5294 includes optional first-order digital high-pass (HP) IIR filter. Figure 46 shows the device block diagram and transfer function.

Equation 1. ADS5294 EQ3_yn3_las776.gif
ADS5294 dig_iir_flt_las176.gifFigure 46. HP Filter Block Diagram

Figure 47 shows the characteristics at k=2 to 10.

ADS5294 HPF_response.pngFigure 47. HP Filter Amplitude Response at K = 2 to 10