SBASAW5 December   2025 ADS112C14 , ADS122C14

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 I2C Timing Requirements
    7. 5.7 I2C Switching Characteristics
    8. 5.8 Timing Diagrams
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Noise Performance
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Analog Inputs and Multiplexer
      2. 7.3.2  Programmable Gain Amplifier (PGA)
      3. 7.3.3  Voltage Reference
        1. 7.3.3.1 Internal Reference
        2. 7.3.3.2 External Reference
        3. 7.3.3.3 Reference Buffers
      4. 7.3.4  Clock Source
      5. 7.3.5  Delta-Sigma Modulator
      6. 7.3.6  Digital Filter
        1. 7.3.6.1 Sinc4 and Sinc4 + Sinc1 Filter
        2. 7.3.6.2 FIR Filter
        3. 7.3.6.3 Digital Filter Latency
        4. 7.3.6.4 Global-Chop Mode
      7. 7.3.7  Excitation Current Sources (IDACs)
      8. 7.3.8  Burn-Out Current Sources (BOCS)
      9. 7.3.9  General Purpose IOs (GPIOs)
        1. 7.3.9.1 FAULT Output
        2. 7.3.9.2 DRDY Output
      10. 7.3.10 System Monitors
        1. 7.3.10.1 Internal Short (Offset Calibration)
        2. 7.3.10.2 Internal Temperature Sensor
        3. 7.3.10.3 External Reference Voltage Readback
        4. 7.3.10.4 Power-Supply Readback
      11. 7.3.11 Monitors and Status Flags
        1. 7.3.11.1 Reset (RESETn flag)
        2. 7.3.11.2 AVDD Undervoltage Monitor (AVDD_UVn flag)
        3. 7.3.11.3 Reference Undervoltage Monitor (REV_UVn flag)
        4. 7.3.11.4 Register Map CRC Fault (REG_MAP_CRC_FAULTn flag)
        5. 7.3.11.5 Internal Memory Fault (MEM_FAULTn flag)
        6. 7.3.11.6 Register Write Fault (REG_WRITE_FAULTn flag)
        7. 7.3.11.7 DRDY Indicator (DRDY bit)
        8. 7.3.11.8 Conversion Counter (CONV_COUNT[3:0])
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power-up and Reset
        1. 7.4.1.1 Power-On Reset (POR)
        2. 7.4.1.2 Reset by Register Write
        3. 7.4.1.3 I2C General Call Reset
      2. 7.4.2 Operating Modes
        1. 7.4.2.1 Idle and Standby Mode
        2. 7.4.2.2 Power-Down Mode
        3. 7.4.2.3 Power-Scalable Conversion Modes
          1. 7.4.2.3.1 Continuous-Conversion Mode
          2. 7.4.2.3.2 Single-shot Conversion Mode
    5. 7.5 Programming
      1. 7.5.1  I2C Interface
      2. 7.5.2  I2C Address
      3. 7.5.3  Serial Clock (SCL) and Serial Data (SDA)
      4. 7.5.4  I2C Bus Speed
      5. 7.5.5  I2C Data Transfer Protocol
      6. 7.5.6  I2C General Call (Software Reset)
      7. 7.5.7  I3C Compatibility
      8. 7.5.8  Commands
        1. 7.5.8.1 RDATA (0000 0000b)
        2. 7.5.8.2 RREG (0100 rrrrb)
        3. 7.5.8.3 WREG (1000 rrrrb)
      9. 7.5.9  STATUS Header
      10. 7.5.10 I2C CRC
      11. 7.5.11 Register Map CRC
      12. 7.5.12 Data Ready (DRDY) Pin
      13. 7.5.13 Monitoring for New Conversion Data
        1. 7.5.13.1 DRDY Pin Monitoring
        2. 7.5.13.2 Reading DRDY Bit and Conversion Counter
        3. 7.5.13.3 Clock Counting
      14. 7.5.14 Conversion Data Format
  9. 8 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Serial Interface Connections
      2. 9.1.2 Connecting Multiple Devices on the Same I2C Bus
      3. 9.1.3 Unused Inputs and Outputs
      4. 9.1.4 Device Initialization
    2. 9.2 Typical Applications
      1. 9.2.1 Software-Configurable RTD Measurement Input
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Performance Plots
        4. 9.2.1.4 Design Variant – 3-Wire RTD Measurement With Automatic Lead-Wire Compensation Using Two IDACs
      2. 9.2.2 Thermocouple Measurement With Cold-Junction Compensation Using a 2-wire RTD
      3. 9.2.3 Resistive Bridge Sensor Measurement With Temperature Compensation
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power Supplies
      2. 9.3.2 Power-Supply Sequencing
      3. 9.3.3 Power-Supply Decoupling
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

7.3.8 Burn-Out Current Sources (BOCS)

To help detect potential sensor faults, the ADS1x2C14 provide a pair of programmable burn-out current sources (BOCS). Use the BOCS[1:0] bits to enable the current sources and to set the values to 0.2μA, 1μA, or 10μA.

The BOCS connect to the PGA inputs after the internal multiplexer. When enabled, one BOCS sources current from AVDD to the selected positive analog input (AINP) and the other BOCS sinks current from the selected negative analog input (AINN) to GND.

In case of an open-circuit in the external sensor or a sensor wire disconnection, these BOCS pull the positive input toward AVDD and the negative input toward GND, resulting in a full-scale reading. A full-scale reading can also indicate that the sensor is overloaded or that the reference voltage is absent. A near-zero reading can indicate a shorted sensor. Distinguishing a shorted sensor condition from a normal reading can be difficult, especially if an RC filter is used at the inputs. The voltage drop across the external filter resistance and the residual resistance of the internal multiplexer created by the current sources can cause the ADC output to read a value larger than zero.

The ADC readings of a functional sensor can be corrupted when the burn-out current sources are enabled. Therefore, disable the burn-out current sources when performing precision measurements, and only enable the BOCS to test for sensor fault conditions during a dedicated diagnostic measurement.

Disable the BOCS when using global-chop mode (GC_EN = 1b). The burn-out current source function is not compatible with global-chop mode.

The burn-out current sources remain active in idle mode, but turn off in standby and power-down mode.