SLUSFQ1A December   2024  – December 2024 BQ41Z90

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions:
  6. 5 Pin Equivalent Diagrams
  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  Supply Current
    6. 6.6  Power Selector
    7. 6.7  Current Wake Detector
    8. 6.8  General Purpose Input-Outputs
    9. 6.9  Aux REGOUT LDO
    10. 6.10 LD Pin
    11. 6.11 Shelf Timer
    12. 6.12 Cell Balancing
    13. 6.13 Comparator-Based Detections (SCOMP)
    14. 6.14 SCOMP Timing Requirements
    15. 6.15 SCD Comparator
    16. 6.16 High-side NFET Drivers (CHG and DSG and PCHG and PDSG)
    17. 6.17 FUSE Pin
    18. 6.18 Flash Memory
    19. 6.19 Interface I/O
    20. 6.20 I2C Interface Timing
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Functional Modes
        1. 7.3.1.1 Analog Front End (AFE)
        2. 7.3.1.2 Power Management
          1. 7.3.1.2.1 Power Mode Block Configuration
          2. 7.3.1.2.2 Power Supply Control
            1. 7.3.1.2.2.1 HIBERNATE Mode
            2. 7.3.1.2.2.2 SHUTDOWN Mode
            3. 7.3.1.2.2.3 SHELF Mode
            4. 7.3.1.2.2.4 Wake Functionality
          3. 7.3.1.2.3 Power Management Unit
            1. 7.3.1.2.3.1 PMU Overview
          4. 7.3.1.2.4 Thermal Shutdown
          5. 7.3.1.2.5 Low Drop Out Regulators (LDOs)
            1. 7.3.1.2.5.1 REG18
            2. 7.3.1.2.5.2 REG135
            3. 7.3.1.2.5.3 REGIO
            4. 7.3.1.2.5.4 REGOUT
        3. 7.3.1.3 Reset Management
          1. 7.3.1.3.1 RST_SD Pin Operation
          2. 7.3.1.3.2 AFE Watchdog
        4. 7.3.1.4 Diagnostics Features
        5. 7.3.1.5 Internal Oscillators
          1. 7.3.1.5.1 Low Frequency Oscillator (LFO)
          2. 7.3.1.5.2 High Frequency Oscillator (HFO)
          3. 7.3.1.5.3 Low Power Oscillator (LPO)
      2. 7.3.2 Temperature Measurement
        1. 7.3.2.1 External Temperature Measurement Support
        2. 7.3.2.2 Internal Temperature Sensor
      3. 7.3.3 Random Cell Connection Support
        1. 7.3.3.1 Usage of VC Pins for Cells Versus Interconnect
        2. 7.3.3.2 Unused Pins
      4. 7.3.4 Cell Balancing Support
        1. 7.3.4.1 Open Wire Detection
      5. 7.3.5 Protection and Charge Control Outputs
        1. 7.3.5.1 High-Side NFET Drivers
        2. 7.3.5.2 PRECHARGE and PREDISCHARGE Modes
        3. 7.3.5.3 FET Configuration
        4. 7.3.5.4 CFETOFF, DFETOFF Pin Functionality
        5. 7.3.5.5 DDSG and DCHG Pin Operation
        6. 7.3.5.6 Hardware Fault Detection (SCOMP and SCD)
        7. 7.3.5.7 FET UVLO Protection
        8. 7.3.5.8 Fuse Drive
      6. 7.3.6 Load Detect Functionality
      7. 7.3.7 MCU Peripherals
        1. 7.3.7.1 General Purpose and Special Function I/O
          1. 7.3.7.1.1 Low Voltage RAx I/O
          2. 7.3.7.1.2 Low Voltage RCx I/O
          3. 7.3.7.1.3 Constant Current Sink I/O
        2. 7.3.7.2 Communication Interfaces
          1. 7.3.7.2.1 I2C Interface
          2. 7.3.7.2.2 SMBus Interface
        3. 7.3.7.3 Authentication Support
          1. 7.3.7.3.1 ECC Authentication
          2. 7.3.7.3.2 SHA-1 Support
          3. 7.3.7.3.3 SHA-2 Support
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
  10. 9 Power Supply Recommendations
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PVP|64
Thermal pad, mechanical data (Package|Pins)
Orderable Information
7.3.7.3.1 ECC Authentication

For robust battery pack security, the BQ41Z90 offers Elliptic Curve Cryptographic (ECC) authentication. ECC authentication uses unique asymmetrical private/public key cryptography, eliminating the requirement of sharing the same secret in the host system.

The ECC authentication protocol in the BQ41Z90 device is the Elliptic Curve Korean Certificate-based Digital Signature Algorithm (EC-KCDSA), implemented based on the International Organization for Standardization (ISO) specification, 14888-3. The EC-KCDSA signature (that is, response from a challenge) is calculated based on the B-163 or B-233 pseudo-random elliptic curve that is standardized and freely available from the National Institute of Standards and Technology (NIST) in the publication FIPS 186-3. Elliptic curve parameters based on B-163 or B-233 will be hard coded into the Mask ROM since these need not be modified.

For reference, see http://csrc.nist.gov/publications/PubsFIPS.html.

The BQ41Z90 includes a hardware-based binary field accelerator peripheral for enhanced performance of the ROM-based EC-KCDSA library functions. The accelerator handles the computation of all binary field additions and multiplications directly in hardware, which allows computations to be done in parallel with other CPU tasks, significantly improving the overall speed of the EC-KCDSA implementation. The top-level EC-KCDSA signature generation protocol is handled in the Mask ROM and uses computation results acquired from the math accelerator to construct the final authentication signature that is provided to the host system via the device serial interface.

The private key and public key can be programmed and stored in physically secure memory that is isolated from Program FLASH, preventing attempts to access or read out its value over the serial interface.

The key pair generation occurs externally so the host system will need knowledge of the public key prior to requesting a signature from the BQ41Z90 device. Similar to SHA-1 authentication, a random challenge must be constructed by the system host and sent to the BQ41Z90 prior to initiating signature generation. From there, the Mask ROM handles execution of all tasks required to communicate with the integrated math accelerator and CPU before making the final result available to the Program FLASH via library function calls.