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

9.4.11 User Calibration

ADC calibration can be performed by the user without using calibration commands. This procedure requires the user to apply the appropriate calibration voltage as with using calibration commands, but in this case the user computes the calibration values based on the conversion result and then writes the value to the calibration registers. The procedure for user calibration is as follows:

  1. Set the OFSCAL[2:0] register = 0h, and GANCAL[2:0] = 400000h. These values set the offset and gain factors to 0 and 1, respectively.
  2. Apply zero voltage or short the inputs (example: set the ADC mux to internal short). Wait for the input voltage and the ADC to settle for a minimum of 63 conversions and then begin averaging of a number of conversion results. Averaging conversions results in a more accurate calibration. Write the 24-bit averaged value to the OFC register.
  3. Apply a DC or AC calibration voltage at least 5% below full-scale. Be sure not to be near or exceed 100% FSR otherwise the conversion data clips, resulting in erroneous calibration. Wait for the calibration voltage and the ADC to settle for a minimum of 63 conversions. Use Equation 15 or Equation 16 to compute the scale factor value.

Equation 15 shows the DC calibration voltage. Use the average value of the ADC data.

Equation 15. ADS1287 q_fsc_code_bas418.gif

Equation 16 shows the AC calibration voltage. Use an RMS value of the ADC data.

Equation 16. ADS1287 q_fsc2-0_bas378.gif