SBAS813 June   2018 ADS8688AT

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  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: Serial Interface
    7. 6.7 Switching Characteristics: Serial Interface
    8. 6.8 Typical Characteristics
  7. 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 Overvoltage Protection Circuit
      4. 7.3.4  Programmable Gain Amplifier (PGA)
      5. 7.3.5  Second-Order, Low-Pass Filter (LPF)
      6. 7.3.6  ADC Driver
      7. 7.3.7  Multiplexer (MUX)
      8. 7.3.8  Reference
        1. 7.3.8.1 Internal Reference
        2. 7.3.8.2 External Reference
      9. 7.3.9  Auxiliary Channel
        1. 7.3.9.1 Input Driver for the AUX Channel
      10. 7.3.10 ADC Transfer Function
      11. 7.3.11 Alarm Feature
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Interface
        1. 7.4.1.1 Digital Pin Description
          1. 7.4.1.1.1 CS (Input)
          2. 7.4.1.1.2 SCLK (Input)
          3. 7.4.1.1.3 SDI (Input)
          4. 7.4.1.1.4 SDO (Output)
          5. 7.4.1.1.5 DAISY (Input)
          6. 7.4.1.1.6 RST/PD (Input)
        2. 7.4.1.2 Data Acquisition Example
        3. 7.4.1.3 Host-to-Device Connection Topologies
          1. 7.4.1.3.1 Daisy-Chain Topology
          2. 7.4.1.3.2 Star Topology
      2. 7.4.2 Device Modes
        1. 7.4.2.1 Continued Operation in the Selected Mode (NO_OP)
        2. 7.4.2.2 Frame Abort Condition (FRAME_ABORT)
        3. 7.4.2.3 STANDBY Mode (STDBY)
        4. 7.4.2.4 Power-Down Mode (PWR_DN)
        5. 7.4.2.5 Auto Channel Enable With Reset (AUTO_RST)
        6. 7.4.2.6 Manual Channel n Select (MAN_Ch_n)
        7. 7.4.2.7 Channel Sequencing Modes
        8. 7.4.2.8 Reset Program Registers (RST)
    5. 7.5 Register Maps
      1. 7.5.1 Command Register Description
      2. 7.5.2 Program Register Description
        1. 7.5.2.1 Program Register Read/Write Operation
        2. 7.5.2.2 Program Register Map
        3. 7.5.2.3 Program Register Descriptions
          1. 7.5.2.3.1 Auto-Scan Sequencing Control Registers
            1. 7.5.2.3.1.1 Auto-Scan Sequence Enable Register (address = 01h)
              1. Table 11. AUTO_SEQ_EN Field Descriptions
            2. 7.5.2.3.1.2 Channel Power Down Register (address = 02h)
              1. Table 12. Channel Power Down Register Field Descriptions
          2. 7.5.2.3.2 Device Features Selection Control Register (address = 03h)
            1. Table 13. Feature Select Register Field Descriptions
          3. 7.5.2.3.3 Range Select Registers (addresses 05h-0Ch)
            1. Table 16. Channel n Input Range Registers Field Descriptions
          4. 7.5.2.3.4 Alarm Flag Registers (Read-Only)
            1. 7.5.2.3.4.1 ALARM Overview Tripped-Flag Register (address = 10h)
              1. Table 17. ALARM Overview Tripped-Flag Register Field Descriptions
            2. 7.5.2.3.4.2 Alarm Flag Registers: Tripped and Active (address = 11h to 14h)
              1. Table 18. ALARM Ch0-3 Tripped-Flag Register Field Descriptions
              2. Table 19. ALARM Ch0-3 Active-Flag Register Field Descriptions
              3. Table 20. ALARM Ch4-7 Tripped-Flag Register Field Descriptions
              4. Table 21. ALARM Ch4-7 Active-Flag Register Field Descriptions
          5. 7.5.2.3.5 Alarm Threshold Setting Registers
            1. Table 22. Channel n Hysteresis Register Field Descriptions (n = 0 to 7)
            2. Table 23. Channel n High Threshold MSB Register Field Descriptions (n = 0 to 7)
            3. Table 24. Channel n High Threshold LSB Register Field Descriptions (n = 0 to 7)
            4. Table 25. Channel n Low Threshold MSB Register Field Descriptions (n = 0 to 7)
            5. Table 26. Channel n Low Threshold MSB Register Field Descriptions (n = 0 to 7)
          6. 7.5.2.3.6 Command Read-Back Register (address = 3Fh)
            1. Table 27. Command Read-Back Register Field Descriptions
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Phase-Compensated, 8-Channel, Multiplexed Data Acquisition System for Power Automation
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 16-Bit, 8-Channel, Integrated Analog Input Module for Programmable Logic Controllers (PLCs)
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.5.2.2 Program Register Map

This section provides a bit-by-bit description of each program register.

Table 10. Program Register Map

REGISTER REGISTER ADDRESS BITS[15:9] DEFAULT VALUE(1) REGISTER BITS
7 6 5 4 3 2 1 0
AUTO SCAN SEQUENCING CONTROL
AUTO_SEQ_EN 01h FFh CH7_EN CH6_EN CH5_EN CH4_EN CH3_EN CH2_EN CH1_EN CH0_EN
Channel Power Down 02h 00h CH7_PD CH6_PD CH5_PD CH4_PD CH3_PD CH2_PD CH1_PD CH0_PD
DEVICE FEATURES SELECTION CONTROL
Feature Select 03h 00h DEV[1:0] 0 ALARM_EN 0 SDO [2:0]
RANGE SELECT REGISTERS
Channel 0 Input Range 05h 00h 0 0 0 0 Range Select Channel 0[3:0]
Channel 1 Input Range 06h 00h 0 0 0 0 Range Select Channel 1[3:0]
Channel 2 Input Range 07h 00h 0 0 0 0 Range Select Channel 2[3:0]
Channel 3 Input Range 08h 00h 0 0 0 0 Range Select Channel 3[3:0]
Channel 4 Input Range 09h 00h 0 0 0 0 Range Select Channel 4[3:0]
Channel 5 Input Range 0Ah 00h 0 0 0 0 Range Select Channel 5[3:0]
Channel 6 Input Range 0Bh 00h 0 0 0 0 Range Select Channel 6[3:0]
Channel 7 Input Range 0Ch 00h 0 0 0 0 Range Select Channel 7[3:0]
ALARM FLAG REGISTERS (Read-Only)
ALARM Overview Tripped-Flag 10h 00h Tripped Alarm Flag Ch7 Tripped Alarm Flag Ch6 Tripped Alarm Flag Ch5 Tripped Alarm Flag Ch4 Tripped Alarm Flag Ch3 Tripped Alarm Flag Ch2 Tripped Alarm Flag Ch1 Tripped Alarm Flag Ch0
ALARM Ch 0-3 Tripped-Flag 11h 00h Tripped Alarm Flag Ch0 Low Tripped Alarm Flag Ch0 High Tripped Alarm Flag Ch1 Low Tripped Alarm Flag Ch1 High Tripped Alarm Flag Ch2 Low Tripped Alarm Flag Ch2 High Tripped Alarm Flag Ch3 Low Tripped Alarm Flag Ch3 High
ALARM Ch 0-3 Active-Flag 12h 00h Active Alarm Flag Ch0 Low Active Alarm Flag Ch0 High Active Alarm Flag Ch1 Low Active Alarm Flag Ch1 High Active Alarm Flag Ch2 Low Active Alarm Flag Ch2 High Active Alarm Flag Ch3 Low Active Alarm Flag Ch3 High
ALARM Ch 4-7 Tripped-Flag 13h 00h Tripped Alarm Flag Ch4 Low Tripped Alarm Flag Ch4 High Tripped Alarm Flag Ch5 Low Tripped Alarm Flag Ch5 High Tripped Alarm Flag Ch6 Low Tripped Alarm Flag Ch6 High Tripped Alarm Flag Ch7 Low Tripped Alarm Flag Ch7 High
ALARM Ch 4-7 Active-Flag 14h 00h Active Alarm Flag Ch4 Low Active Alarm Flag Ch4 High Active Alarm Flag Ch5 Low Active Alarm Flag Ch5 High Active Alarm Flag Ch6 Low Active Alarm Flag Ch6 High Active Alarm Flag Ch7 Low Active Alarm Flag Ch7 High
ALARM THRESHOLD REGISTERS
Ch 0 Hysteresis 15h 00h CH0_HYST[7:0]
Ch 0 High Threshold MSB 16h FFh CH0_HT[15:8]
Ch 0 High Threshold LSB 17h FFh CH0_HT[7:0]
Ch 0 Low Threshold MSB 18h 00h CH0_LT[15:8]
Ch 0 Low Threshold LSB 19h 00h CH0_LT[7:0]
… … … See the alarm threshold setting registers for details regarding the ALARM threshold settings registers.
Ch 7 Hysteresis 38h 00h CH7_HYST[7:0]
Ch 7 High Threshold MSB 39h FFh CH7_HT[15:8]
Ch 7 High Threshold LSB 3Ah FFh CH7_HT[7:0]
Ch 7 Low Threshold MSB 3Bh 00h CH7_LT[15:8]
Ch 7 Low Threshold LSB 3Ch 00h CH7_LT[7:0]
COMMAND READ BACK (Read-Only)
Command Read Back 3Fh 00h COMMAND_WORD[7:0]
(1) All registers are reset to the default values at power-on or at device reset using the register settings method.