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

7.4.4 High-Precision Mode

High-precision mode increases the accuracy of the data measurement by accumulating ADC conversion results. This accumulation is useful for applications where the level of precision required to accurately measure the sensor output must be higher than 12 bits.

For this mode, set the OPMODE_SEL register to 111b. In this mode, the ADC starts converting and starts accumulating the conversion results in an accumulator when the SEQ_START bit is set. The ADC stops accumulating after 16 conversion results. The accumulator contains one 16-bit conversion result. The ADC has an accumulator for each analog input channel. If the operation of the ADC is aborted in high-precision mode before the BUSY/RDY pin goes low because the SEQ_ABORT bit is set by the user, the ADC provides invalid data and the internal data buffer (Figure 7-8), provides zeroes as output. In this mode, the BUSY/RDY can wake up the MCU or host from sleep or hibernation when accumulation completes. The steps for configuring the ADC into high-precision mode are illustrated in Figure 7-23.

GUID-A402D41E-B249-459F-8C5B-FAFCF3DA1DB0-low.gif
A. For setting the operation mode to high-precision mode, see Figure 7-11.
B. Select the channels in the AUTO_SEQ_CHEN register.
C. Select the oscillator by configuring the OSC_SEL register and configure the NCLK_SEL register.
D. Enable the accumulator by setting the bits in the ACC_EN register.
E. Set the SEQ_START bit in the START_SEQUENCE register.
F. Read the ACC_CHx_xxx registers.
G. Select another operation mode in the OPMODE_SEL register.
H. For reading and writing registers, see the Section 7.5 section.
Figure 7-23 Configuring ADC in High-Precision Mode

Abort the current sequence by setting the SEQ_ABORT bit before changing the ADC operation mode or ADC configuration.

Figure 7-24 and Figure 7-25 show the accumulation of conversion results in high-precision mode.

GUID-2C7B9DEF-4809-4479-A482-665E1FF0CFB5-low.gifFigure 7-24 High-Precision Mode With Single-Channel Configurations
GUID-B56F5174-EC04-44AE-9323-631D46253470-low.gifFigure 7-25 High-Precision Mode With Dual-Channel Configurations