ZHCSGU6A september   2017  – july 2023 ADS8588H

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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: CONVST Control
    7. 6.7  Timing Requirements: Data Read Operation
    8. 6.8  Timing Requirements: Parallel Data Read Operation, CS and RD Tied Together
    9. 6.9  Timing Requirements: Parallel Data Read Operation, CS and RD Separate
    10. 6.10 Timing Requirements: Serial Data Read Operation
    11. 6.11 Timing Requirements: Byte Mode Data Read Operation
    12. 6.12 Timing Requirements: Oversampling Mode
    13. 6.13 Timing Requirements: Exit Standby Mode
    14. 6.14 Timing Requirements: Exit Shutdown Mode
    15. 6.15 Switching Characteristics: CONVST Control
    16. 6.16 Switching Characteristics: Parallel Data Read Operation, CS and RD Tied Together
    17. 6.17 Switching Characteristics: Parallel Data Read Operation, CS and RD Separate
    18. 6.18 Switching Characteristics: Serial Data Read Operation
    19. 6.19 Switching Characteristics: Byte Mode Data Read Operation
    20. 6.20 Timing Diagrams
    21. 6.21 Typical Characteristics
  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
      2. 7.3.2  Analog Input Impedance
      3. 7.3.3  Input Clamp Protection Circuit
      4. 7.3.4  Programmable Gain Amplifier (PGA)
      5. 7.3.5  Third-Order, Low-Pass Filter (LPF)
      6. 7.3.6  ADC Driver
      7. 7.3.7  Digital Filter and Noise
      8. 7.3.8  Reference
        1. 7.3.8.1 Internal Reference
        2. 7.3.8.2 External Reference
        3. 7.3.8.3 Supplying One VREF to Multiple Devices
      9. 7.3.9  ADC Transfer Function
      10. 7.3.10 ADS8588H Device Family Comparison
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Interface: Pin Description
        1. 7.4.1.1  REFSEL (Input)
        2. 7.4.1.2  RANGE (Input)
        3. 7.4.1.3  STBY (Input)
        4. 7.4.1.4  PAR/SER/BYTE SEL (Input)
        5. 7.4.1.5  CONVSTA, CONVSTB (Input)
        6. 7.4.1.6  RESET (Input)
        7. 7.4.1.7  RD/SCLK (Input)
        8. 7.4.1.8  CS (Input)
        9. 7.4.1.9  OS[2:0]
        10. 7.4.1.10 BUSY (Output)
        11. 7.4.1.11 FRSTDATA (Output)
        12. 7.4.1.12 DB15/BYTE SEL
        13. 7.4.1.13 DB14/HBEN
        14. 7.4.1.14 DB[13:9]
        15. 7.4.1.15 DB8/DOUTB
        16. 7.4.1.16 DB7/DOUTA
        17. 7.4.1.17 DB[6:0]
      2. 7.4.2 Device Modes of Operation
        1. 7.4.2.1 Power-Down Modes
          1. 7.4.2.1.1 Standby Mode
          2. 7.4.2.1.2 Shutdown Mode
        2. 7.4.2.2 Conversion Control
          1. 7.4.2.2.1 Simultaneous Sampling on All Input Channels
          2. 7.4.2.2.2 Simultaneous Sampling Two Sets of Input Channels
        3. 7.4.2.3 Data Read Operation
          1. 7.4.2.3.1 Parallel Data Read
          2. 7.4.2.3.2 Parallel Byte Data Read
          3. 7.4.2.3.3 Serial Data Read
          4. 7.4.2.3.4 Data Read During Conversion
        4. 7.4.2.4 Oversampling Mode of Operation
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 接收文档更新通知
    3. 9.3 支持资源
    4. 9.4 Trademarks
    5. 9.5 静电放电警告
    6. 9.6 术语表
  11. 10Mechanical, Packaging, and Orderable Information

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7.3.8.2 External Reference

For applications that require a reference voltage with lower temperature drift or a common reference voltage for multiple devices, the ADS8588H offers a provision to use an external reference, using the internal buffer to drive the ADC reference pin. In order to select the external reference mode, either tie the REFSEL pin low or connect this pin to AGND. In this mode, an external 2.5-V reference must be applied at REFIN/REFOUT (pin 42), which becomes a high-impedance input pin. Any low-drift, small-size external reference can be used in this mode because the internal buffer is optimally designed to handle the dynamic loading on the ADC reference input. The output of the external reference must be filtered to minimize the resulting effect of the reference noise on system performance. Figure 7-10 shows a typical connection diagram for this mode.

GUID-F81F0CE5-FEF0-462E-BD34-D9AD6EA5A49E-low.gifFigure 7-10 Device Connections for Using an External 2.5-V Reference

For closed-loop operation of the internal reference buffer, the REFCAPA and REFCAPB pins must be externally shorted together. The output of the internal reference buffer appears at the REFCAP pin. A minimum capacitance of 10 µF must be placed between the REFCAPA, REFCAPB pins and REFGND (pin 43). Do not use this internal reference buffer to drive external ac or dc loads because of the limited current output capability of the buffer.

The performance of the internal buffer output (as shown in Figure 7-11) is very stable across the entire operating temperature range of –40°C to +125°C. The typical specified value of the reference buffer drift over temperature is 5 ppm/°C (Figure 7-12).

GUID-E257F5A7-23D6-44EB-A5F9-F889FD0468F5-low.gif
 
Figure 7-11 Variation of Reference Buffer Output (REFCAPA, REFCAPB) vs Free-Air Temperature and Supply
GUID-9E0D950D-8E80-413C-B7D4-E0A29CD25D2D-low.gif
Number of samples = 30
Figure 7-12 Reference Buffer Temperature Drift Histogram