SBAS633E February   2016  – August 2022 ADS8681 , ADS8685 , ADS8689

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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: Conversion Cycle
    7. 6.7  Timing Requirements: Asynchronous Reset
    8. 6.8  Timing Requirements: SPI-Compatible Serial Interface
    9. 6.9  Timing Requirements: Source-Synchronous Serial Interface (External Clock)
    10. 6.10 Timing Requirements: Source-Synchronous Serial Interface (Internal Clock)
    11. 6.11 Timing Diagrams
    12. 6.12 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 Input Structure
      2. 7.3.2 Analog Input Impedance
      3. 7.3.3 Input 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 Reference
        1. 7.3.7.1 Internal Reference
        2. 7.3.7.2 External Reference
      8. 7.3.8 ADC Transfer Function
      9. 7.3.9 Alarm Features
        1. 7.3.9.1 Input Alarm
        2. 7.3.9.2 AVDD Alarm
    4. 7.4 Device Functional Modes
      1. 7.4.1 Host-to-Device Connection Topologies
        1. 7.4.1.1 Single Device: All multiSPI Options
        2. 7.4.1.2 Single Device: Standard SPI Interface
        3. 7.4.1.3 Multiple Devices: Daisy-Chain Topology
      2. 7.4.2 Device Operational Modes
        1. 7.4.2.1 RESET State
        2. 7.4.2.2 ACQ State
        3. 7.4.2.3 CONV State
    5. 7.5 Programming
      1. 7.5.1 Data Transfer Frame
      2. 7.5.2 Input Command Word and Register Write Operation
      3. 7.5.3 Output Data Word
      4. 7.5.4 Data Transfer Protocols
        1. 7.5.4.1 Protocols for Configuring the Device
        2. 7.5.4.2 Protocols for Reading From the Device
          1. 7.5.4.2.1 Legacy, SPI-Compatible (SYS-xy-S) Protocols with a Single SDO-x
          2. 7.5.4.2.2 Legacy, SPI-Compatible (SYS-xy-S) Protocols With Dual SDO-x
          3. 7.5.4.2.3 Source-Synchronous (SRC) Protocols
            1. 7.5.4.2.3.1 Output Clock Source Options
            2. 7.5.4.2.3.2 Output Bus Width Options
    6. 7.6 Register Maps
      1. 7.6.1 Device Configuration and Register Maps
        1. 7.6.1.1 DEVICE_ID_REG Register (address = 00h)
        2. 7.6.1.2 RST_PWRCTL_REG Register (address = 04h)
        3. 7.6.1.3 SDI_CTL_REG Register (address = 08h)
        4. 7.6.1.4 SDO_CTL_REG Register (address = 0Ch)
        5. 7.6.1.5 DATAOUT_CTL_REG Register (address = 10h)
        6. 7.6.1.6 RANGE_SEL_REG Register (address = 14h)
        7. 7.6.1.7 ALARM_REG Register (address = 20h)
        8. 7.6.1.8 ALARM_H_TH_REG Register (address = 24h)
        9. 7.6.1.9 ALARM_L_TH_REG Register (address = 28h)
  8. 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 Curves
    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
  9. 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
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PW|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.6.1.7 ALARM_REG Register (address = 20h)

This register contains the output alarm flags (active and tripped) for the input and AVDD alarm.

Figure 7-42 ALARM_REG Register
31302928272625242322212019181716
Reserved
R-0000h
1514131211109876543210
ACTIVE_VDD_L_FLAGACTIVE_VDD_H_FLAGReservedACTIVE_IN_L_
FLAG		ACTIVE_IN_H_
FLAG		ReservedTRP_
VDD_L_
FLAG		TRP_
VDD_H_
FLAG		TRP_IN_L_FLAGTRP_IN_H_FLAGReservedOVW_
ALARM
R-0bR-0bR-00bR-0bR-0bR-00bR-0bR-0bR-0bR-0bR-000bR-0b
LEGEND: R = Read only; -n = value after reset; -0, -1 = Condition after application reset; -<0>, -<1> = Condition after power-on reset
Address for bits 7-0 = 20hAddress for bits 15-8 = 21hAddress for bits 23-16 = 22hAddress for bits 31-24 = 23h
Table 7-17 ALARM_REG Register Field Descriptions
BitFieldTypeResetDescription
31-16ReservedR0000hReserved. Reads return 0000h.
15ACTIVE_VDD_L_FLAGR0bActive ALARM output flag for low AVDD voltage.
0b = No ALARM condition
1b = ALARM condition exists
14ACTIVE_VDD_H_FLAGR0bActive ALARM output flag for high AVDD voltage.
0b = No ALARM condition
1b = ALARM condition exists
13-12ReservedR00bReserved. Reads return 00b.
11ACTIVE_IN_L_FLAGR0bActive ALARM output flag for low input voltage.
0b = No ALARM condition
1b = ALARM condition exists
10ACTIVE_IN_H_FLAGR0bActive ALARM output flag for high input voltage.
0b = No ALARM condition
1b = ALARM condition exists
9-8ReservedR00bReserved. Reads return 00b.
7TRP_VDD_L_FLAGR0bTripped ALARM output flag for low AVDD voltage.
0b = No ALARM condition
1b = ALARM condition exists
6TRP_VDD_H_FLAGR0bTripped ALARM output flag for high AVDD voltage.
0b = No ALARM condition
1b = ALARM condition exists
5TRP_IN_L_FLAGR0bTripped ALARM output flag for low input voltage.
0b = No ALARM condition
1b = ALARM condition exists
4TRP_IN_H_FLAGR0bTripped ALARM output flag for high input voltage.
0b = No ALARM condition
1b = ALARM condition exists
3-1ReservedR000bReserved. Reads return 000b.
0OVW_ALARMR0bLogical OR outputs all tripped ALARM flags.
0b = No ALARM condition
1b = ALARM condition exists