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

7.3.3.1 Usage of VC Pins for Cells Versus Interconnect

If the BQ41Z90 device is used in a system with fewer than 16-series cells, the additional cell inputs can be utilized to improve measurement performance. For example, a long connection may exist between two cells in a pack, such that there may be significant interconnect resistance between the cells, such as shown in Figure 7-3 between CELL-A and CELL-B. By connecting VC12 close to the positive terminal of CELL-B, and connecting VC13 close to the negative terminal of CELL-A, more accurate cell voltage measurements are obtained for CELL-A and CELL-B, since the I·R voltage across the interconnect resistance between the cells is not included in either cell voltage measurement. Since the device reports the voltage across the interconnect resistance and the synchronized current, the resistance of the interconnect between CELL-A and CELL-B can also be calculated and monitored during operation. It is recommended to include the series resistance and bypass capacitor on cell inputs connected in this manner, as shown below.

Note: It is important that the differential input for each cell input not fall below –0.3V (the Absolute Maximum data sheet limit), with the recommended minimum voltage of –0.2V. Therefore, it is important that the I·R voltage drop across the interconnect resistance does not cause a violation of this requirement.
BQ41Z90 Using Cell Input Pins for Interconnect Measurement Figure 7-3 Using Cell Input Pins for Interconnect Measurement

If this connection across an interconnect is not needed (or it is preferred to avoid the extra resistor and capacitor), then the unused cell input pins should be shorted to adjacent cell input pins, as shown in Figure 7-4 for VC13.

BQ41Z90 Terminating an Unused Cell Input Pin Figure 7-4 Terminating an Unused Cell Input Pin

Figure 7-5 shows the standard cell to VC pin connection for different series cell count configurations. The device uses this information to disable cell voltage protections associated with inputs which are used to measure interconnect or are not used at all. Voltage measurements for all inputs are reported in 16-bit format (in units of mV) as well as 32-bit format (in units of raw ADC counts), irrespective of whether they are used for cells or not.

BQ41Z90 Standard Cell to VC pin Connections for Different Cell Count Figure 7-5 Standard Cell to VC pin Connections for Different Cell Count