SLUSAM9E July   2011  – April 2020

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
  4. Revision History
  5. Description (Continued)
  6. Pin Configuration and Functions
    1.     Pin Functions
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: Supply Current
    6. 7.6  Internal Power Control (Startup and Shutdown)
    7. 7.7  3.3-V Voltage Regulator
    8. 7.8  Voltage Reference
    9. 7.9  Cell Voltage Amplifier
    10. 7.10 Current Sense Amplifier
    11. 7.11 Overcurrent Comparator
    12. 7.12 Internal Temperature Measurement
    13. 7.13 Cell Balancing and Open Cell Detection
    14. 7.14 I2C Compatible Interface
    15. 7.15 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Internal LDO Voltage Regulator
      2. 8.3.2 ADC Interface
        1. 8.3.2.1 Reference Voltage
          1. 8.3.2.1.1 Host ADC Calibration
        2. 8.3.2.2 Cell Voltage Monitoring
          1. 8.3.2.2.1 Cell Amplifier Headroom Under Extreme Cell Imbalance
          2. 8.3.2.2.2 Cell Amplifier Headroom Under BAT Voltage Drop
        3. 8.3.2.3 Current Monitoring
        4. 8.3.2.4 Overcurrent Monitoring
        5. 8.3.2.5 Temperature Monitoring
          1. 8.3.2.5.1 Internal Temperature Monitoring
      3. 8.3.3 Cell Balancing and Open Cell Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power Modes
        1. 8.4.1.1 POWER ON RESET (POR)
        2. 8.4.1.2 STANDBY
        3. 8.4.1.3 SLEEP
    5. 8.5 Programming
      1. 8.5.1 Host Interface
        1. 8.5.1.1 I2C Addressing
        2. 8.5.1.2 Bus Write Command to BQ76925
        3. 8.5.1.3 Bus Read Command from BQ76925 Device
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Recommended System Implementation
        1. 9.1.1.1 Voltage, Current, and Temperature Outputs
        2. 9.1.1.2 Power Management
        3. 9.1.1.3 Low Dropout (LDO) Regulator
        4. 9.1.1.4 Input Filters
        5. 9.1.1.5 Output Filters
      2. 9.1.2 Cell Balancing
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Pin Configuration and Functions

PW Package
20-Pin TTSOP
Top View
BQ76925 pos_lusam9.gif
RGE Package
24-Pin QFN With Thermal Pad
Top View
BQ76925 po_lusam9_qfn.gif

Pin Functions

NAME PIN NO. TYPE DESCRIPTION
TSSOP VQFN
VCTL 1 23 Output 3.3-V Regulator control voltage(1)
ALERT 13 13 Output Overcurrent alert (open drain)
BAT 2 24 Power Supply voltage, tied to most positive cell
NC 9, 10, 21, 22 No Connection (leave open)
SCL 19 19 Input I2C Clock (open drain)
SDA 18 18 Input / Output I2C Data (open drain)
SENSEN 11 11 Input Negative current sense
SENSEP 12 12 Input Positive current sense
V3P3 20 20 Output 3.3-V Regulator
VC6 3 1 Input Sense voltage for most positive cell
VC5 4 2 Input Sense voltage for second most positive cell
VC4 5 3 Input Sense voltage for third most positive cell
VC3 6 4 Input Sense voltage for fourth most positive cell
VC2 7 5 Input Sense voltage for fifth most positive cell
VC1 8 6 Input Sense voltage for least positive cell
VC0 9 7 Input Sense voltage for negative end of cell stack
VCOUT 15 15 Output Cell measurement voltage
VIOUT 14 14 Output Current measurement voltage
VREF 17 17 Output Reference voltage for ADC
VSS 10 8 Power Ground
VTB 16 16 Output Bias voltage for thermistor network
When a bypass FET is used to supply the regulated 3.3-V load current, VCTL automatically adjusts to keep V3P3 = 3.3 V. If VCTL is tied to BAT, the load current is supplied through V3P3.