SBASAI9 December   2025 ADS112S14 , ADS122S14

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 Timing Requirements
    7. 5.7 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 SPI CRC Fault (SPI_CRC_FAULTn flag)
        5. 7.3.11.5 Register Map CRC Fault (REG_MAP_CRC_FAULTn flag)
        6. 7.3.11.6 Internal Memory Fault (MEM_FAULTn flag)
        7. 7.3.11.7 Register Write Fault (REG_WRITE_FAULTn flag)
        8. 7.3.11.8 DRDY Indicator (DRDY bit)
        9. 7.3.11.9 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 Reset by SPI Input Pattern
      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  Serial Interface (SPI)
      2. 7.5.2  Serial Interface Signals
        1. 7.5.2.1 Chip Select (CS)
        2. 7.5.2.2 Serial Clock (SCLK)
        3. 7.5.2.3 Serial Data Input (SDI)
        4. 7.5.2.4 Serial Data Output/Data Ready (SDO/DRDY)
        5. 7.5.2.5 Data Ready (DRDY) Pin
      3. 7.5.3  Serial Interface Communication Structure
        1. 7.5.3.1 SPI Frame
        2. 7.5.3.2 STATUS Header
        3. 7.5.3.3 SPI CRC
      4. 7.5.4  Device Commands
        1. 7.5.4.1 No Operation (Read Conversion Data)
        2. 7.5.4.2 Read Register Command
        3. 7.5.4.3 Write Register Command
      5. 7.5.5  Continuous-Read Mode
        1. 7.5.5.1 Read Registers in Continuous-Read Mode
      6. 7.5.6  Daisy-Chain Operation
      7. 7.5.7  3-Wire SPI Mode
        1. 7.5.7.1 3-Wire SPI Mode Frame Re-Alignment
      8. 7.5.8  Monitoring for New Conversion Data
        1. 7.5.8.1 DRDY Pin or SDO/DRDY Pin Monitoring
        2. 7.5.8.2 Reading DRDY Bit and Conversion Counter
        3. 7.5.8.3 Clock Counting
      9. 7.5.9  DRDY Pin Behavior
      10. 7.5.10 Conversion Data Format
      11. 7.5.11 Register Map CRC
  9. 8 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Serial Interface Connections
      2. 9.1.2 Interfacing with Multiple Devices
      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

7.5.1 Serial Interface (SPI)

The serial interface is used to read conversion data, configure device registers, and control ADC conversions.

The serial interface consists of four lines: CS, SCLK, SDI, and SDO/DRDY. In addition, GPIO3 can be configured as a dedicated DRDY output pin. The host always drives SCLK and the device acts as a peripheral. The interface only supports the SPI configuration (CPOL = 0 and CPHA = 1), where SCLK idles low, and data update on SCLK rising edges and are latched on SCLK falling edges.

The interface supports full-duplex operation, meaning input data and output data can be transmitted simultaneously. The interface also supports daisy-chain connection of multiple ADCs.