JAJSHV5B June   2017  – August 2019 ADS1287

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      機能ブロック図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Noise Performance
  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 and Multiplexer
      2. 9.3.2 Programmable Gain Amplifier (PGA)
      3. 9.3.3 Modulator
        1. 9.3.3.1 Modulator Overrange
      4. 9.3.4 Voltage Reference Inputs (REFP, REFN)
      5. 9.3.5 Digital Filter
        1. 9.3.5.1 Sinc Filter Stage
        2. 9.3.5.2 FIR Filter Stage
        3. 9.3.5.3 Group Delay and Step Response
          1. 9.3.5.3.1 Linear Phase Response
          2. 9.3.5.3.2 Minimum Phase Response
        4. 9.3.5.4 HPF Stage
      6. 9.3.6 Reset (RESET Pin and Reset Command)
      7. 9.3.7 Master Clock Input (CLK)
    4. 9.4 Device Functional Modes
      1. 9.4.1  Operational Mode
      2. 9.4.2  Chop Mode
      3. 9.4.3  Offset
      4. 9.4.4  Power-Down Mode
      5. 9.4.5  Standby Mode
      6. 9.4.6  Synchronization
        1. 9.4.6.1 Pulse-Sync Mode
        2. 9.4.6.2 Continuous-Sync Mode
      7. 9.4.7  Reading Data
        1. 9.4.7.1 Read-Data-Continuous Mode (RDATAC)
        2. 9.4.7.2 Stop-Read-Data-Continuous-Mode (SDATAC)
      8. 9.4.8  Conversion Data Format
      9. 9.4.9  Offset and Full-Scale Calibration Registers
        1. 9.4.9.1 OFC[2:0] Registers
        2. 9.4.9.2 FSC[2:0] Registers
      10. 9.4.10 Calibration Command
        1. 9.4.10.1 OFSCAL Command
        2. 9.4.10.2 GANCAL Command
      11. 9.4.11 User Calibration
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
        1. 9.5.1.1 Chip Select (CS)
        2. 9.5.1.2 Serial Clock (SCLK)
        3. 9.5.1.3 Data Input (DIN)
        4. 9.5.1.4 Data Output (DOUT)
        5. 9.5.1.5 Serial Interface Timeout
        6. 9.5.1.6 Data Ready (DRDY)
      2. 9.5.2 Commands
        1. 9.5.2.1  WAKEUP: Wake Up Command
        2. 9.5.2.2  STANDBY: Standby Mode Command
        3. 9.5.2.3  SYNC: Synchronize ADC Conversions
        4. 9.5.2.4  RESET: Reset Command
        5. 9.5.2.5  RDATAC: Read Data Continuous Mode Command
        6. 9.5.2.6  SDATAC: Stop Read Data Continuous Mode Command
        7. 9.5.2.7  RDATA: Read Data Command
        8. 9.5.2.8  RREG: Read Register Data Command
        9. 9.5.2.9  WREG: Write Register Data Command
        10. 9.5.2.10 OFSCAL: Offset Calibration Command
        11. 9.5.2.11 GANCAL: Gain Calibration Command
    6. 9.6 Register Map
      1. 9.6.1 Register Descriptions
        1. 9.6.1.1 ID/CFG: ID, Configuration Register (address = 00h) [reset = x0h]
          1. Table 22. ID/CFG Register Field Descriptions
        2. 9.6.1.2 CONFIG0: Configuration Register 0 (address = 01h) [reset = 52h]
          1. Table 23. CONFIG0 Register Field Descriptions
        3. 9.6.1.3 CONFIG1: Configuration Register 1 (address = 02h) [reset = 08h]
          1. Table 24. CONFIG1 Register Field Descriptions
        4. 9.6.1.4 High-Pass Filter Corner Frequency (HPFx) Registers (address = 03h, 04h) [reset = 32h, 03h]
          1. Table 25. HPF0, HPF1 Registers Field Description
        5. 9.6.1.5 Offset Calibration (OFCx) Registers (address = 05h, 06h, 07h) [reset = 00h, 00h, 00h]
          1. Table 26. OFC0, OFC1, OFC2 Registers Field Description
        6. 9.6.1.6 Full-Scale Calibration (FSCx) Registers (address = 08h, 09h, 0Ah) [reset = 00h, 00h, 40h]
          1. Table 27. FSC0, FSC1, FSC2 Registers Field Description
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Geophone Application
      2. 10.2.2 Digital Interface
    3. 10.3 Initialization Set Up
  11. 11Power Supply Recommendations
    1. 11.1 Analog Power Supplies
    2. 11.2 Digital Power Supply
    3. 11.3 Power-Supply Sequence
  12. 12Layout
    1. 12.1 Layout Guidelines
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 ドキュメントの更新通知を受け取る方法
    2. 13.2 コミュニティ・リソース
    3. 13.3 商標
    4. 13.4 静電気放電に関する注意事項
    5. 13.5 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

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • RHF|24
サーマルパッド・メカニカル・データ
発注情報

9.4.3 Offset

As with most ΔΣ modulators, the ADC can produce low-level idle tones (typically 140 dB below the full-scale amplitude). The idle tones appear as low-frequency components in the output data when either no- or low-level signals are present. Typically, idle tones do not occur when high-level signals are present. The ADC incorporates an internal offset option that is intended to reduce the amplitudes of the tone. The offset is recommended for the low-power mode operation only and is not recommended for the high-resolution mode operation. Use the external offset circuit illustrated in the Application Information section for idle tone reduction in high-resolution mode operation.

The offset is enabled by the OFFSET bit of the ID_CFG register. The offset voltage is 50 mV. The 50-mV offset leads to 2% reduction of the input range that is restored by calibrating the offset voltage by use of the offset calibration registers. Offset correction is accomplished by performing offset calibration, or to provide nominal correction, write 029700h to the calibration registers.