ZHCSK67B June   2017  – August 2019 ADS1287

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      功能方框图
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Performance
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Analog Input and Multiplexer
      2. 8.3.2 Programmable Gain Amplifier (PGA)
      3. 8.3.3 Modulator
        1. 8.3.3.1 Modulator Overrange
      4. 8.3.4 Voltage Reference Inputs (REFP, REFN)
      5. 8.3.5 Digital Filter
        1. 8.3.5.1 Sinc Filter Stage
        2. 8.3.5.2 FIR Filter Stage
        3. 8.3.5.3 Group Delay and Step Response
          1. 8.3.5.3.1 Linear Phase Response
          2. 8.3.5.3.2 Minimum Phase Response
        4. 8.3.5.4 HPF Stage
      6. 8.3.6 Reset (RESET Pin and Reset Command)
      7. 8.3.7 Master Clock Input (CLK)
    4. 8.4 Device Functional Modes
      1. 8.4.1  Operational Mode
      2. 8.4.2  Chop Mode
      3. 8.4.3  Offset
      4. 8.4.4  Power-Down Mode
      5. 8.4.5  Standby Mode
      6. 8.4.6  Synchronization
        1. 8.4.6.1 Pulse-Sync Mode
        2. 8.4.6.2 Continuous-Sync Mode
      7. 8.4.7  Reading Data
        1. 8.4.7.1 Read-Data-Continuous Mode (RDATAC)
        2. 8.4.7.2 Stop-Read-Data-Continuous-Mode (SDATAC)
      8. 8.4.8  Conversion Data Format
      9. 8.4.9  Offset and Full-Scale Calibration Registers
        1. 8.4.9.1 OFC[2:0] Registers
        2. 8.4.9.2 FSC[2:0] Registers
      10. 8.4.10 Calibration Command
        1. 8.4.10.1 OFSCAL Command
        2. 8.4.10.2 GANCAL Command
      11. 8.4.11 User Calibration
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Chip Select (CS)
        2. 8.5.1.2 Serial Clock (SCLK)
        3. 8.5.1.3 Data Input (DIN)
        4. 8.5.1.4 Data Output (DOUT)
        5. 8.5.1.5 Serial Interface Timeout
        6. 8.5.1.6 Data Ready (DRDY)
      2. 8.5.2 Commands
        1. 8.5.2.1  WAKEUP: Wake Up Command
        2. 8.5.2.2  STANDBY: Standby Mode Command
        3. 8.5.2.3  SYNC: Synchronize ADC Conversions
        4. 8.5.2.4  RESET: Reset Command
        5. 8.5.2.5  RDATAC: Read Data Continuous Mode Command
        6. 8.5.2.6  SDATAC: Stop Read Data Continuous Mode Command
        7. 8.5.2.7  RDATA: Read Data Command
        8. 8.5.2.8  RREG: Read Register Data Command
        9. 8.5.2.9  WREG: Write Register Data Command
        10. 8.5.2.10 OFSCAL: Offset Calibration Command
        11. 8.5.2.11 GANCAL: Gain Calibration Command
    6. 8.6 Register Map
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1 ID/CFG: ID, Configuration Register (address = 00h) [reset = x0h]
          1. Table 22. ID/CFG Register Field Descriptions
        2. 8.6.1.2 CONFIG0: Configuration Register 0 (address = 01h) [reset = 52h]
          1. Table 23. CONFIG0 Register Field Descriptions
        3. 8.6.1.3 CONFIG1: Configuration Register 1 (address = 02h) [reset = 08h]
          1. Table 24. CONFIG1 Register Field Descriptions
        4. 8.6.1.4 High-Pass Filter Corner Frequency (HPFx) Registers (address = 03h, 04h) [reset = 32h, 03h]
          1. Table 25. HPF0, HPF1 Registers Field Description
        5. 8.6.1.5 Offset Calibration (OFCx) Registers (address = 05h, 06h, 07h) [reset = 00h, 00h, 00h]
          1. Table 26. OFC0, OFC1, OFC2 Registers Field Description
        6. 8.6.1.6 Full-Scale Calibration (FSCx) Registers (address = 08h, 09h, 0Ah) [reset = 00h, 00h, 40h]
          1. Table 27. FSC0, FSC1, FSC2 Registers Field Description
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Geophone Application
      2. 9.2.2 Digital Interface
    3. 9.3 Initialization Set Up
  10. 10Power Supply Recommendations
    1. 10.1 Analog Power Supplies
    2. 10.2 Digital Power Supply
    3. 10.3 Power-Supply Sequence
  11. 11Layout
    1. 11.1 Layout Guidelines
  12. 12器件和文档支持
    1. 12.1 接收文档更新通知
    2. 12.2 社区资源
    3. 12.3 商标
    4. 12.4 静电放电警告
    5. 12.5 Glossary
  13. 13机械、封装和可订购信息

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • RHF|24
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.1 Noise Performance

SNR and input-referred noise are related parameters that define the ADC effective resolution. Use Equation 1 to calculate SNR from the input-referred noise data:

Equation 1. ADS1287 q_snr_20log_bas418.gif

where

    Table 1 through Table 4 list SNR and noise performance data. Noise performance data are listed for high-resolution and low-power modes, with and without chop enabled. The noise performance data are representative of typical ADC performance at TA = 25°C. The data are the standard deviation of consecutive ADC conversion results with the ADC inputs shorted over the signal bandwidth of 0.1 Hz to 0.413 fDATA. Repeated noise measurements can yield higher or lower noise results because of the statistical nature of noise.

    Noise performance depends on several ADC operating parameters: high-resolution or low-power mode, data rate, PGA gain, and chop mode. Best noise performance is achieved by operating the ADC in high-resolution mode. Noise performance also depends on the data rate. For example, as the data rate decreases, the ADC bandwidth and thus total noise decreases. Using higher gain factors improves input-referred noise, but the calculated SNR decreases because of a 6-dB decrease of input range for each gain step. Chop mode improves noise performance by removing 1/f noise from the PGA. Chop mode is particularly important for lowest noise operation when used with low data rates or high gain. Chop mode is the recommended mode for geophone sensors.

    Table 1. High-Resolution Mode Noise Performance (Chop Enabled)(1)

    fDATA (SPS) SNR (dB) INPUT-REFERRED NOISE (µVRMS)
    GAIN GAIN
    1 2 4 8 16 1 2 4 8 16
    62.5 125 125 125 124 122 0.96 0.49 0.25 0.14 0.09
    125 122 122 122 121 119 1.36 0.68 0.35 0.19 0.13
    250 119 119 119 118 116 1.90 0.97 0.50 0.28 0.18
    500 116 116 116 115 113 2.70 1.36 0.71 0.39 0.25
    1000 113 113 113 112 110 3.85 1.95 1.00 0.55 0.36
    (1) Typical performance data at TA = 25°C. SNR data are rounded. Measurement bandwidth: 0.1 Hz to 0.413 fDATA.

    Table 2. High-Resolution Mode Noise Performance (Chop Disabled)(1)

    fDATA (SPS) SNR (dB) INPUT-REFERRED NOISE (µVRMS)
    GAIN GAIN
    1 2 4 8 16 1 2 4 8 16
    62.5 125 125 123 120 114 0.99 0.52 0.31 0.23 0.23
    125 122 122 121 119 114 1.36 0.70 0.39 0.26 0.22
    250 119 119 118 116 113 1.90 0.97 0.54 0.34 0.26
    500 116 116 116 114 111 2.70 1.38 0.73 0.43 0.32
    1000 113 113 113 111 109 3.85 1.95 1.03 0.60 0.41
    (1) Typical performance data at TA = 25°C. SNR data are rounded. Measurement bandwidth: 0.1 Hz to 0.413 fDATA.

    Table 3. Low-Power Mode Noise Performance (Chop Enabled, Offset Enabled)(1)

    fDATA (SPS) SNR (dB) INPUT-REFERRED NOISE (µVRMS)
    GAIN GAIN
    1 2 4 8 16 1 2 4 8 16
    62.5 123 123 122 121 118 1.33 0.66 0.36 0.20 0.14
    125 120 119 119 118 115 1.86 0.96 0.50 0.29 0.20
    250 117 116 116 115 112 2.65 1.36 0.70 0.41 0.29
    500 113 113 113 112 109 3.81 1.91 1.01 0.58 0.40
    1000 110 110 110 109 106 5.50 2.79 1.48 0.84 0.58
    (1) Typical performance data at TA = 25°C. SNR data are rounded. Measurement bandwidth: 0.1 Hz to 0.413 fDATA.

    Table 4. Low-Power Mode Noise Performance (Chop Disabled, Offset Enabled) (1)

    fDATA (SPS) SNR (dB) INPUT-REFERRED NOISE (µVRMS)
    GAIN GAIN
    1 2 4 8 16 1 2 4 8 16
    62.5 122 122 121 118 113 1.36 0.71 0.40 0.29 0.24
    125 119 119 118 116 112 1.90 0.97 0.53 0.36 0.29
    250 116 116 115 114 110 2.67 1.38 0.74 0.46 0.35
    500 113 113 113 111 108 3.75 1.93 1.02 0.62 0.46
    1000 110 110 110 108 105 5.53 2.80 1.48 0.88 0.62
    (1) Typical performance data at TA = 25°C. SNR data are rounded. Measurement bandwidth: 0.1 Hz to 0.413 fDATA.