JAJSOX0A March   2024  – June 2024 ADS127L18

ADVANCE INFORMATION  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Timing Diagrams
  7. 6 Parameter Measurement Information
    1. 6.1  Offset Error Measurement
    2. 6.2  Offset Drift Measurement
    3. 6.3  Gain Error Measurement
    4. 6.4  Gain Drift Measurement
    5. 6.5  NMRR Measurement
    6. 6.6  CMRR Measurement
    7. 6.7  PSRR Measurement
    8. 6.8  SNR Measurement
    9. 6.9  INL Error Measurement
    10. 6.10 THD Measurement
    11. 6.11 IMD Measurement
    12. 6.12 SFDR Measurement
    13. 6.13 Noise Performance
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Inputs (AINP, AINN)
        1. 7.3.1.1 Input Range
      2. 7.3.2 Reference Voltage (REFP, REFN)
        1. 7.3.2.1 Reference Voltage Range
      3. 7.3.3 Clock Operation
        1. 7.3.3.1 Internal Oscillator
        2. 7.3.3.2 External Clock
      4. 7.3.4 Power Supplies
        1. 7.3.4.1 AVDD1 and AVSS
        2. 7.3.4.2 AVDD2
        3. 7.3.4.3 IOVDD
        4. 7.3.4.4 Power-On Reset (POR)
        5. 7.3.4.5 CAPA and CAPD
      5. 7.3.5 VCM Output Voltage
      6. 7.3.6 GPIO
      7. 7.3.7 Modulator
      8. 7.3.8 Digital Filter
        1. 7.3.8.1 Wideband Filter
      9. 7.3.9 Low-Latency Filter (Sinc)
        1. 7.3.9.1 Sinc4 Filter
        2. 7.3.9.2 Sinc4 + Sinc1 Cascade Filter
        3. 7.3.9.3 Sinc3 Filter
        4. 7.3.9.4 Sinc3 + Sinc1 Filter
    4. 7.4 Device Functional Modes
      1. 7.4.1  Speed Modes
      2. 7.4.2  Synchronization
        1. 7.4.2.1 Synchronized Control Mode
        2. 7.4.2.2 Start/Stop Control Mode
      3. 7.4.3  Digital Filter Settling
      4. 7.4.4  Conversion-Start Delay Time
      5. 7.4.5  Data Averaging
      6. 7.4.6  Calibration
        1. 7.4.6.1 Offset Calibration Registers
        2. 7.4.6.2 Gain Calibration Registers
        3. 7.4.6.3 Calibration Procedure
      7. 7.4.7  Reset
        1. 7.4.7.1 RESET Pin
        2. 7.4.7.2 Reset by SPI Register
        3. 7.4.7.3 Reset by SPI Input Pattern
      8. 7.4.8  Power-Down
      9. 7.4.9  Idle and Standby Modes
      10. 7.4.10 Diagnostics
        1. 7.4.10.1 ERROR Pin and ERR_FLAG Bit
        2. 7.4.10.2 Clock Counter
        3. 7.4.10.3 SCLK Counter
        4. 7.4.10.4 Frame-Sync CRC
        5. 7.4.10.5 SPI CRC
        6. 7.4.10.6 Register Map CRC
        7. 7.4.10.7 Self Test
      11. 7.4.11 Frame-Sync Data Port
        1. 7.4.11.1 FSYNC Pin
        2. 7.4.11.2 DCLK Pin
        3. 7.4.11.3 DOUT Pins
        4. 7.4.11.4 DIN Pins
        5. 7.4.11.5 Time Division Multiplexing
        6. 7.4.11.6 Daisy Chain
        7. 7.4.11.7 Data Packet
        8. 7.4.11.8 STATUS_DP Header
        9. 7.4.11.9 Data Port Timing Adjustment
    5. 7.5 Programming
      1. 7.5.1 Hardware Programming
      2. 7.5.2 SPI Programming
        1. 7.5.2.1 Chip Select (CS)
        2. 7.5.2.2 Serial Clock (SCLK)
        3. 7.5.2.3 Serial Data Input (SDI)
        4. 7.5.2.4 Serial Data Output (SDO)
      3. 7.5.3 SPI Frame
      4. 7.5.4 SPI Commands
        1. 7.5.4.1 Read Register Command
        2. 7.5.4.2 Write Register Command
      5. 7.5.5 SPI Daisy-Chain
  9. 8 Register Map
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Input Driver
      2. 9.1.2 Antialias Filter
      3. 9.1.3 Reference Voltage
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Mechanical Data

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

7.4.5 Data Averaging

The ADC supports channel-to-channel averaging to create higher resolution data from the original channel data. Averaging occurs across channels in groups of two, four, or eight, as programmed by the AVG_MODE[1:0] bits of the GEN_CFG2 register. In typical use, the signal is applied in parallel to the channels to be averaged. When the noise between channels is uncorrelated, the dynamic range improvement is (+dB) = 20 × log(√n), where n = number of channels averaged. Program the channels to the same data rate (OSR) in average mode.

Averaging is performed after the offset, gain, and output code clip operations. Therefore, averaging is based on the final output data from each channel. If clipped data occurs in a channel, the clipped data also reflects in the averaged result. The MOD_FLAG of the DP_STATUS header is an OR of the original channel MOD_FLAG status bits. Table 7-11 shows the channel slot assignment for the new averaged data. The original channel data are not available. If desired, pack the averaged channel data the same as the original channel data (TDM mode).

Table 7-10 Data Averaging Modes
CHANNEL SLOT 2-CHANNEL AVERAGING 4-CHANNEL AVERAGING 8-CHANNEL AVERAGING
CH0 Average of CH0, CH1 Average of CH0−CH3 ADS127L18: Average of CH0−CH7
CH1 Average of CH2, CH3 ADS127L18: Average of CH4−CH7 —
CH2 ADS127L18: Average of CH4, CH5 — —
CH3 ADS127L18: Average of CH6, CH7 — —