SBAS891B November   2017  – September 2022 ADS7142-Q1

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: All Modes
    6. 6.6  Electrical Characteristics: Manual Mode
    7. 6.7  Electrical Characteristics: Autonomous Modes
    8. 6.8  Electrical Characteristics: High Precision Mode
    9. 6.9  Timing Requirements
    10. 6.10 Switching Characteristics
    11. 6.11 Timing Diagrams
    12. 6.12 Typical Characteristics: All Modes
    13. 6.13 Typical Characteristics: Manual Mode
    14. 6.14 Typical Characteristics: Autonomous Modes
    15. 6.15 Typical Characteristics: High-Precision Mode
  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 and Multiplexer
        1. 7.3.1.1 Two-Channel, Single-Ended Configuration
        2. 7.3.1.2 Single-Channel, Single-Ended Configuration With Remote Ground Sense
        3. 7.3.1.3 Single-Channel, Pseudo-Differential Configuration
      2. 7.3.2  Offset Calibration
      3. 7.3.3  Reference
      4. 7.3.4  ADC Transfer Function
      5. 7.3.5  Oscillator and Timing Control
      6. 7.3.6  I2C Address Selector
      7. 7.3.7  Data Buffer
        1. 7.3.7.1 Filling of the Data Buffer
        2. 7.3.7.2 Reading Data From the Data Buffer
      8. 7.3.8  Accumulator
      9. 7.3.9  Digital Window Comparator
      10. 7.3.10 I2C Protocol Features
        1. 7.3.10.1 General Call
        2. 7.3.10.2 General Call With Software Reset
        3. 7.3.10.3 General Call With Write Software Programmable Part of the Target Address
        4. 7.3.10.4 Configuring the ADC Into High-Speed I2C Mode
        5. 7.3.10.5 Bus Clear
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Power Up and Reset
      2. 7.4.2 Manual Mode
        1. 7.4.2.1 Manual Mode With CH0 Only
        2. 7.4.2.2 Manual Mode With AUTO Sequence
      3. 7.4.3 Autonomous Modes
        1. 7.4.3.1 Autonomous Mode With Threshold Monitoring and Diagnostics
          1. 7.4.3.1.1 Autonomous Mode With Pre-ALERT Data
          2. 7.4.3.1.2 Autonomous Mode With Post-ALERT Data
        2. 7.4.3.2 Autonomous Mode With Burst Data
          1. 7.4.3.2.1 Autonomous Mode With Start Burst
          2. 7.4.3.2.2 Autonomous Mode With Stop Burst
      4. 7.4.4 High-Precision Mode
    5. 7.5 Programming
      1. 7.5.1 Reading Registers
        1. 7.5.1.1 Single Register Read
        2. 7.5.1.2 Reading a Continuous Block of Registers
      2. 7.5.2 Writing Registers
        1. 7.5.2.1 Single Register Write
        2. 7.5.2.2 Writing a Continuous Block of Registers
        3. 7.5.2.3 Set Bit
        4. 7.5.2.4 Clear Bit
    6. 7.6 Register Map
      1. 7.6.1 Page1 Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 ADS7142-Q1 as a Programmable Comparator With False Trigger Prevention and Diagnostics
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Programmable Thresholds and Hysteresis
          2. 8.2.1.2.2 False Trigger Prevention With an Event Counter
          3. 8.2.1.2.3 Fault Diagnostics With the Data Buffer
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Voltage and Temperature Monitoring in Remote Camera Modules Using the ADS7142-Q1
        1. 8.2.2.1 Design Requirements
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 AVDD and DVDD Supply Recommendations
    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 Electrostatic Discharge Caution
    2. 9.2 Glossary
    3. 9.3 Trademarks
    4. 9.4 Receiving Notification of Documentation Updates
    5. 9.5 Support Resources
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.3 Autonomous Modes

In autonomous mode, the ADC can be programmed to monitor the voltage applied on the analog input pins. The ADC generates a signal on the ALERT pin when the programmable high or low threshold values are crossed. The host processor can read the ADC conversion results from the internal data buffer.

In autonomous mode, the first start of conversion must be provided by the host and the ADC generates the subsequent start of conversions. The ADC initiates the following start of conversions using the internal oscillator.

After configuring the operation mode to autonomous mode (set the OPMODE_SEL register to 110b), as illustrated in Figure 7-11, steps for operating the ADC to be in different autonomous modes are illustrated in Figure 7-14.

GUID-F18C4194-0AB8-4F9C-96CE-3F6C7E0C1177-low.gif
A. For setting the operation mode to Autonomous modes, see Figure 7-11.
B. Select channels in the AUTO_SEQ_CHEN register.
C. Select the oscillator by configuring the OSC_SEL register and configure the NCLK_SEL register.
D. Select the data buffer mode in the DATA_BUFFER_OPMODE register.
E. Configure the thresholds in the DWC_xTH_CHx_xxx registers and hysteresis in the DWC_HYS_CHx registers. Enable the alert for channels in the ALERT_CHEN register and set the DWC_BLOCK_EN bit in the ALERT_DWC_EN register.
F. Set the bit SEQ_START bit in the START_SEQUENCE register.
G. Read the ALERT_LOW_FLAGS and ALERT_HIGH_FLAGS registers.
H. Reset the ALERT_LOW_FLAGS and ALERT_HIGH_FLAGS registers by writing 03h.
I. See the Section 7.3.7.2 section.
J. Select another operation mode in the OPMODE_SEL register.
K. For reading and writing registers, see the Section 7.5 section.
Figure 7-14 Configuring ADC in Autonomous Modes

Abort the present sequence by setting the SEQ_ABORT bit in the ABORT_SEQUENCE register before changing the ADC operation mode or ADC configuration.