SBASA22A september   2022  – july 2023 ADS131B26-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
    7. 6.7 Switching Characteristics
    8. 6.8 Timing Diagram
    9. 6.9 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Offset Drift Measurement
    2. 7.2 Gain Drift Measurement
    3. 7.3 Noise Performance
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Naming Conventions
      2. 8.3.2 Precision Voltage References (REFA, REFB)
      3. 8.3.3 Clocking (MCLK, OSCM, OSCD)
      4. 8.3.4 ADC1y
        1. 8.3.4.1 ADC1y Input Multiplexer
        2. 8.3.4.2 ADC1y Programmable Gain Amplifier (PGA)
        3. 8.3.4.3 ADC1y ΔΣ Modulator
        4. 8.3.4.4 ADC1y Digital Filter
        5. 8.3.4.5 ADC1y Offset and Gain Calibration
        6. 8.3.4.6 ADC1y Conversion Data
      5. 8.3.5 ADC2y
        1. 8.3.5.1 ADC2y Input Multiplexer
        2. 8.3.5.2 ADC2y Programmable Gain Amplifier (PGA)
        3. 8.3.5.3 ADC2y ΔΣ Modulator
        4. 8.3.5.4 ADC2y Digital Filter
        5. 8.3.5.5 ADC2y Offset and Gain Calibration
        6. 8.3.5.6 ADC2y Sequencer
        7. 8.3.5.7 VCMy Buffers
        8. 8.3.5.8 ADC2y Measurement Configurations
        9. 8.3.5.9 ADC2y Conversion Data
      6. 8.3.6 ADC3y
      7. 8.3.7 General-Purpose Digital Inputs and Outputs (GPIO0 to GPIO4)
        1. 8.3.7.1 GPIOx PWM Output Configuration
        2. 8.3.7.2 GPIOx PWM Input Readback
      8. 8.3.8 General-Purpose Digital Inputs and Outputs (GPIO0A, GPIO1A, GPIO0B, GPIO1B)
      9. 8.3.9 Monitors and Diagnostics
        1. 8.3.9.1  Supply Monitors
        2. 8.3.9.2  Clock Monitors
        3. 8.3.9.3  Digital Monitors
          1. 8.3.9.3.1 Register Map CRC
          2. 8.3.9.3.2 Memory Map CRC
          3. 8.3.9.3.3 GPIO Readback
        4. 8.3.9.4  Communication Monitors
        5. 8.3.9.5  Fault Flags and Fault Masking
        6. 8.3.9.6  FAULT Pin
        7. 8.3.9.7  Diagnostics and Diagnostic Procedure
        8. 8.3.9.8  Indicators
        9. 8.3.9.9  Conversion and Sequence Counters
        10. 8.3.9.10 Supply Voltage Readback
        11. 8.3.9.11 Temperature Sensors (TSA, TSB)
        12. 8.3.9.12 Test DACs (TDACA, TDACB)
        13. 8.3.9.13 Open-Wire Detection
        14. 8.3.9.14 Missing Host Detection and MHD Pin
        15. 8.3.9.15 Overcurrent Comparators (OCCA, OCCB)
          1. 8.3.9.15.1 OCCA and OCCB Pins
          2. 8.3.9.15.2 Overcurrent Indication Response Time
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Up and Reset
        1. 8.4.1.1 Power-On Reset (POR)
        2. 8.4.1.2 RESETn Pin
        3. 8.4.1.3 RESET Command
      2. 8.4.2 Operating Modes
        1. 8.4.2.1 Active Mode
        2. 8.4.2.2 Standby Mode
        3. 8.4.2.3 Power-Down Mode
      3. 8.4.3 ADC Conversion Modes
        1. 8.4.3.1 ADC1y and ADC3y Conversion Modes
          1. 8.4.3.1.1 Continuous-Conversion Mode
          2. 8.4.3.1.2 Single-Shot Conversion Mode
          3. 8.4.3.1.3 Global-Chop Mode
            1. 8.4.3.1.3.1 Overcurrent Indication Response Time in Global-Chop Mode
        2. 8.4.3.2 ADC2y Sequencer Operation and Sequence Modes
          1. 8.4.3.2.1 Continuous Sequence Mode
          2. 8.4.3.2.2 Single-Shot Sequence Mode
          3. 8.4.3.2.3 Synchronized Single-Shot Sequence Mode Based on ADC1y Conversion Starts
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Serial Interface Signals
          1. 8.5.1.1.1 Chip Select (CSn)
          2. 8.5.1.1.2 Serial Data Clock (SCLK)
          3. 8.5.1.1.3 Serial Data Input (SDI)
          4. 8.5.1.1.4 Serial Data Output (SDO)
          5. 8.5.1.1.5 Data Ready (DRDYn)
        2. 8.5.1.2 Serial Interface Communication Structure
          1. 8.5.1.2.1 SPI Communication Frames
          2. 8.5.1.2.2 SPI Communication Words
          3. 8.5.1.2.3 STATUS Word
          4. 8.5.1.2.4 Communication Cyclic Redundancy Check (CRC)
          5. 8.5.1.2.5 Commands
            1. 8.5.1.2.5.1 NULL (0000 0000 0000 0000b)
            2. 8.5.1.2.5.2 RESET (0000 0000 0001 0001b)
            3. 8.5.1.2.5.3 LOCK (0000 0101 0101 0101b)
            4. 8.5.1.2.5.4 UNLOCK (0000 0110 0101 0101b)
            5. 8.5.1.2.5.5 WREG (011a aaaa aaa0 0nnnb)
            6. 8.5.1.2.5.6 RREG (101a aaaa aaan nnnnb)
          6. 8.5.1.2.6 SCLK Counter
          7. 8.5.1.2.7 SPI Timeout
          8. 8.5.1.2.8 Reading ADC1A, ADC1B, ADC2A, ADC2B, ADC3A, and ADC3B Conversion Data
          9. 8.5.1.2.9 DRDYn Pin Behavior
    6. 8.6 Register Map
      1. 8.6.1 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Unused Inputs and Outputs
      2. 9.1.2 Minimum Interface Connections
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Current-Shunt Measurement
        2. 9.2.2.2 Battery-Pack Voltage Measurement
        3. 9.2.2.3 Other Voltage Measurements
        4. 9.2.2.4 Shunt Temperature Measurement
        5. 9.2.2.5 Analog Output Temperature Sensor Measurement
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power-Supply Options
        1. 9.3.1.1 Single Unregulated External 4-V to 16-V Supply (3.3-V Digital I/O Levels)
        2. 9.3.1.2 Single Regulated External 3.3-V Supply (3.3-V Digital IO Levels)
        3. 9.3.1.3 Single Regulated External 5-V Supply (5-V Digital I/O Levels)
      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. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.9.5 Fault Flags and Fault Masking

Every monitor in the ADS131B26-Q1 has a corresponding fault flag (see Table 8-15) that sets to 0b when the respective monitor detects a fault condition. As shown in Table 8-19, the RESETn and communication related fault flags are located in the STATUS_MSB register, whereas the supply, clock, and digital related fault flags are grouped together in detailed status registers. The STATUS_MSB register is transmitted as part of the STATUS word at the beginning of every SPI frame as described in the STATUS Word section. To allow immediate indication of any of the supply, clock, or digital related faults as part of the STATUS word, every detailed status register has a corresponding combined fault flag in the STATUS_MSB register. That is, if any of the fault flags in the detailed status register set to 0b, then the combined fault flag sets to 0b as well.

Table 8-19 Detailed Status Registers and Corresponding Combined Fault Flags
MONITOR FAULT FLAGS FOR: DETAILED STATUS REGISTER LOCATION COMBINED FAULT FLAG
IN STATUS_MSB REGISTER
Supply SUPPLY_STATUS SUPPLY_FAULTn
Clock CLOCK_STATUS CLOCK_FAULTn
Digital DIGITAL_STATUS DIGITAL_FAULTn

To clear a set combined fault flag to 1b, the host must first clear all set fault flags in the corresponding detailed status register. Only after all fault flags in the detailed status register are cleared to 1b can the host clear the combined fault flag by writing 1b.

The ADS131B26-Q1 allows additional masking of individual fault flags located in the detailed status registers from triggering the combined fault flag in the STATUS_MSB register. The masking bits are located in the SUPPLY_FAULT_MASK, CLOCK_FAULT_MASK, and DIGITAL_FAULT_MASK registers. If a fault flag in a detailed status register is masked, a fault indicated by this masked fault flag does not trigger a fault indication of the combined fault flag in the STATUS_MSB register. However, the fault is still indicated by the fault flag in the detailed status register.

The following examples for the AVDD OV monitor explain the various configuration options:

  • No AVDD OV fault indication required in either SUPPLY_STATUS (AVDD_OVn fault flag) or STATUS_MSB (SUPPLY_FAULTn fault flag) register: Disable the AVDD OV monitor by setting AVDD_OV_EN = 0b.
  • AVDD OV fault indication in SUPPLY_STATUS, but not in STATUS_MSB register: Enable the AVDD OV monitor by setting AVDD_OV_EN = 1b. Mask the AVDD_OVn fault flag from triggering the SUPPLY_FAULTn fault flag by setting AVDD_OV_MASK = 1b.
  • AVDD OV fault indication in both SUPPLY_STATUS and STATUS_MSB register: Enable the AVDD OV monitor by setting AVDD_OV_EN = 1b. Unmask the AVDD_OVn fault flag by setting AVDD_OV_MASK = 0b.