SBASAY5A June   2024  – May 2025 ADS8681W , ADS8685W , ADS8689W

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Analog Input Structure
      2. 6.3.2 Analog Input Impedance
      3. 6.3.3 Input Protection Circuit
      4. 6.3.4 Programmable Gain Amplifier (PGA)
      5. 6.3.5 Second-Order, Low-Pass Filter (LPF)
      6. 6.3.6 ADC Driver
      7. 6.3.7 Reference
        1. 6.3.7.1 Internal Reference
        2. 6.3.7.2 External Reference
      8. 6.3.8 ADC Transfer Function
      9. 6.3.9 Alarm Features
        1. 6.3.9.1 Input Alarm
        2. 6.3.9.2 AVDD Alarm
    4. 6.4 Device Functional Modes
      1. 6.4.1 Host-to-Device Connection Topologies
        1. 6.4.1.1 Single Device: All multiSPI Options
        2. 6.4.1.2 Single Device: Standard SPI Interface
        3. 6.4.1.3 Multiple Devices: Daisy-Chain Topology
      2. 6.4.2 Device Operational Modes
        1. 6.4.2.1 RESET State
        2. 6.4.2.2 ACQ State
        3. 6.4.2.3 CONV State
    5. 6.5 Programming
      1. 6.5.1 Data Transfer Frame
      2. 6.5.2 Input Command Word and Register Write Operation
      3. 6.5.3 Output Data Word
      4. 6.5.4 Data Transfer Protocols
        1. 6.5.4.1 Protocols for Configuring the Device
        2. 6.5.4.2 Protocols for Reading From the Device
          1. 6.5.4.2.1 Legacy, SPI-Compatible (SYS-xy-S) Protocols With a Single SDO-x
          2. 6.5.4.2.2 Legacy, SPI-Compatible (SYS-xy-S) Protocols With Dual SDO-x
          3. 6.5.4.2.3 Source-Synchronous (SRC) Protocols
            1. 6.5.4.2.3.1 Output Clock Source Options
            2. 6.5.4.2.3.2 Output Bus Width Options
  8. 7 Register Maps
    1. 7.1 Device Configuration and Register Maps
      1. 7.1.1 DEVICE_ID_REG Register (address = 00h)
      2. 7.1.2 RST_PWRCTL_REG Register (address = 04h)
      3. 7.1.3 SDI_CTL_REG Register (address = 08h)
      4. 7.1.4 SDO_CTL_REG Register (address = 0Ch)
      5. 7.1.5 DATAOUT_CTL_REG Register (address = 10h)
      6. 7.1.6 RANGE_SEL_REG Register (address = 14h)
      7. 7.1.7 ALARM_REG Register (address = 20h)
      8. 7.1.8 ALARM_H_TH_REG Register (address = 24h)
      9. 7.1.9 ALARM_L_TH_REG Register (address = 28h)
  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
        1. 8.2.2.1 Alarm Function
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power Supply Decoupling
      2. 8.3.2 Power Saving
        1. 8.3.2.1 NAP Mode
        2. 8.3.2.2 Power-Down (PD) Mode
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.1.8 ALARM_H_TH_REG Register (address = 24h)

This register controls the hysteresis and high threshold for the input alarm.

The address for bits 7-0, 15-8, 23-16, and 31-24 is 24h, 25h, 26h, and 27h, respectively.

Figure 7-8 ALARM_H_TH_REG Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
INP_ALRM_HYST[7:0] Reserved
R/W-00h R-00h
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
INP_ALRM_HIGH_TH[15:0]
R/W-FFFFh
Table 7-10 ALARM_H_TH_REG Register Field Descriptions
Bit Field Type Reset Description
31-24 INP_ALRM_HYST[7:0] R/W 00h The INP_ALRM_HYST[7:2] bits are the 6-bit hysteresis value for the input ALARM.
Set the INP_ALRM_HYST[1:0] bits to 00b.
23-16 Reserved R 00h Reserved. Reads return 00h.
15-0 INP_ALRM_HIGH_TH[15:0] R/W FFFFh These bits are the threshold for comparison.