SBASA22B September   2022  – January 2025 ADS131B26-Q1

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 Diagram
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Offset Drift Measurement
    2. 6.2 Gain Drift Measurement
    3. 6.3 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 Naming Conventions
      2. 7.3.2 Precision Voltage References (REFA, REFB)
      3. 7.3.3 Clocking (MCLK, OSCM, OSCD)
      4. 7.3.4 ADC1y
        1. 7.3.4.1 ADC1y Input Multiplexer
        2. 7.3.4.2 ADC1y Programmable Gain Amplifier (PGA)
        3. 7.3.4.3 ADC1y ΔΣ Modulator
        4. 7.3.4.4 ADC1y Digital Filter
        5. 7.3.4.5 ADC1y Offset and Gain Calibration
        6. 7.3.4.6 ADC1y Conversion Data
      5. 7.3.5 ADC2y
        1. 7.3.5.1 ADC2y Input Multiplexer
        2. 7.3.5.2 ADC2y Programmable Gain Amplifier (PGA)
        3. 7.3.5.3 ADC2y ΔΣ Modulator
        4. 7.3.5.4 ADC2y Digital Filter
        5. 7.3.5.5 ADC2y Offset and Gain Calibration
        6. 7.3.5.6 ADC2y Sequencer
        7. 7.3.5.7 VCMy Buffers
        8. 7.3.5.8 ADC2y Measurement Configurations
        9. 7.3.5.9 ADC2y Conversion Data
      6. 7.3.6 ADC3y
      7. 7.3.7 General-Purpose Digital Inputs and Outputs (GPIO0 to GPIO4)
        1. 7.3.7.1 GPIOx PWM Output Configuration
        2. 7.3.7.2 GPIOx PWM Input Readback
      8. 7.3.8 General-Purpose Digital Inputs and Outputs (GPIO0A, GPIO1A, GPIO0B, GPIO1B)
      9. 7.3.9 Monitors and Diagnostics
        1. 7.3.9.1  Supply Monitors
        2. 7.3.9.2  Clock Monitors
        3. 7.3.9.3  Digital Monitors
          1. 7.3.9.3.1 Register Map CRC
          2. 7.3.9.3.2 Memory Map CRC
          3. 7.3.9.3.3 GPIO Readback
        4. 7.3.9.4  Communication Monitors
        5. 7.3.9.5  Fault Flags and Fault Masking
        6. 7.3.9.6  FAULT Pin
        7. 7.3.9.7  Diagnostics and Diagnostic Procedure
        8. 7.3.9.8  Indicators
        9. 7.3.9.9  Conversion and Sequence Counters
        10. 7.3.9.10 Supply Voltage Readback
        11. 7.3.9.11 Temperature Sensors (TSA, TSB)
        12. 7.3.9.12 Test DACs (TDACA, TDACB)
        13. 7.3.9.13 Open-Wire Detection
        14. 7.3.9.14 Missing Host Detection and MHD Pin
        15. 7.3.9.15 Overcurrent Comparators (OCCA, OCCB)
          1. 7.3.9.15.1 OCCA and OCCB Pins
          2. 7.3.9.15.2 Overcurrent Indication Response Time
    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 RESETn Pin
        3. 7.4.1.3 RESET Command
      2. 7.4.2 Operating Modes
        1. 7.4.2.1 Active Mode
        2. 7.4.2.2 Standby Mode
        3. 7.4.2.3 Power-Down Mode
      3. 7.4.3 ADC Conversion Modes
        1. 7.4.3.1 ADC1y and ADC3y Conversion Modes
          1. 7.4.3.1.1 Continuous-Conversion Mode
          2. 7.4.3.1.2 Single-Shot Conversion Mode
          3. 7.4.3.1.3 Global-Chop Mode
            1. 7.4.3.1.3.1 Overcurrent Indication Response Time in Global-Chop Mode
        2. 7.4.3.2 ADC2y Sequencer Operation and Sequence Modes
          1. 7.4.3.2.1 Continuous Sequence Mode
          2. 7.4.3.2.2 Single-Shot Sequence Mode
          3. 7.4.3.2.3 Synchronized Single-Shot Sequence Mode Based on ADC1y Conversion Starts
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
        1. 7.5.1.1 Serial Interface Signals
          1. 7.5.1.1.1 Chip Select (CSn)
          2. 7.5.1.1.2 Serial Data Clock (SCLK)
          3. 7.5.1.1.3 Serial Data Input (SDI)
          4. 7.5.1.1.4 Serial Data Output (SDO)
          5. 7.5.1.1.5 Data Ready (DRDYn)
        2. 7.5.1.2 Serial Interface Communication Structure
          1. 7.5.1.2.1 SPI Communication Frames
          2. 7.5.1.2.2 SPI Communication Words
          3. 7.5.1.2.3 STATUS Word
          4. 7.5.1.2.4 Communication Cyclic Redundancy Check (CRC)
          5. 7.5.1.2.5 Commands
            1. 7.5.1.2.5.1 NULL (0000 0000 0000 0000b)
            2. 7.5.1.2.5.2 RESET (0000 0000 0001 0001b)
            3. 7.5.1.2.5.3 LOCK (0000 0101 0101 0101b)
            4. 7.5.1.2.5.4 UNLOCK (0000 0110 0101 0101b)
            5. 7.5.1.2.5.5 WREG (011a aaaa aaa0 0nnnb)
            6. 7.5.1.2.5.6 RREG (101a aaaa aaan nnnnb)
          6. 7.5.1.2.6 SCLK Counter
          7. 7.5.1.2.7 SPI Timeout
          8. 7.5.1.2.8 Reading ADC1A, ADC1B, ADC2A, ADC2B, ADC3A, and ADC3B Conversion Data
          9. 7.5.1.2.9 DRDYn Pin Behavior
  9. 8 Register Map
    1. 8.1 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. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

3 Description

The ADS131B26-Q1 is a fully integrated, high-voltage battery pack monitor for automotive electrical vehicle (EV) battery management systems (BMS).

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
ADS131B26-Q1 PHP (HTQFP, 48) 9mm × 9mm
(1) For more information, see the Mechanical, Packaging, and Orderable Information.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
ADS131B26-Q1 EV BMS Battery Pack Monitor System Block Diagram EV BMS Battery Pack Monitor System Block Diagram

The ADS131B26-Q1 integrates two simultaneous-sampling, high-precision, 24-bit analog-to-digital converter (ADC) channels (ADC1A, ADC1B) to redundantly measure battery current with high resolution and accuracy using an external shunt resistor. Two independent digital comparators enable fast overcurrent detection in parallel with the two ADCs.

Another set of two simultaneous-sampling, 24-bit ADCs (ADC3A, ADC3B) are integrated to measure battery pack voltage using external high-voltage resistor dividers synchronously to the battery current for accurate battery state-of-charge and state-of-health calculations.

Additionally, two multiplexed, 16-bit ADC channels (ADC2A, ADC2B) are available to measure shunt temperature and other voltages in the system, such as battery-pack voltage, using external high-voltage resistor dividers. Shunt temperature is measured using an external temperature sensor, such as a thermistor or an analog output temperature sensor. Each ADC is equipped with a channel sequencer that automatically steps through the configured multiplexer inputs to reduce communication on the SPI.

The device integrates many monitoring and diagnostic features to mitigate and detect random hardware faults to aid in the development of functionally safe BMS.

Internal linear regulators with input ranges up to 16V support powering the device with unregulated DC/DC converters.

The ADS131B26-Q1 is offered in a 48-pin HTQFP package and is specified over the automotive temperature range of –40°C to +105°C.