SLVAE87B December   2020  – June 2025 BQ79600-Q1 , BQ79612-Q1 , BQ79614-Q1 , BQ79616-Q1 , BQ79652-Q1 , BQ79654-Q1 , BQ79656-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 NPN LDO Supply
  5. 2 AVDD, CVDD Outputs and DVDD, NEG5, REFHP and REFHM
    1. 2.1 Base Device
    2. 2.2 Design Summary
  6. 3 OTP Programming
  7. 4 Cell Voltage Sense (VCn) and Cell Balancing (CBn)
    1. 4.1 Cell Voltage Sense (VCn)
    2. 4.2 Cell Balancing (CBn)
      1. 4.2.1 Non-Adjacent Cell Balancing
      2. 4.2.2 Adjacent Cell Balancing
      3. 4.2.3 Cell Balancing With External FET
    3. 4.3 Using Fewer Than 16 Cells
      1. 4.3.1 Design Summary
  8. 5 Bus Bar Support
    1. 5.1 Bus Bar on BBP or BBN
    2. 5.2 Typical Connection
      1. 5.2.1 Cell Balancing Handling
    3. 5.3 Bus Bar on Individual VC Channel
    4. 5.4 Multiple Bus Bar Connections
      1. 5.4.1 Two Bus Bar Connections to One Device
      2. 5.4.2 Three Bus Bar Connections to One Device
      3. 5.4.3 Cell Balancing Handling
  9. 6 TSREF
  10. 7 General Purpose Input-Output (GPIO) Configurations
    1. 7.1 Ratiometric Temperature Measurement
    2. 7.2 SPI Mode
      1. 7.2.1 Support 8 NTC Thermistors With SPI Slave Device
      2. 7.2.2 Design Summary
  11. 8 Base and Bridge Device Configuration
    1. 8.1 Power Mode Pings and Tones
      1. 8.1.1 Power Mode Pings
      2. 8.1.2 Power Mode Tones
      3. 8.1.3 Ping and Tone Propagation
    2. 8.2 UART Physical Layer
      1. 8.2.1 Design Considerations
  12. 9 Daisy-Chain Stack Configuration
    1. 9.1 Communication Line Isolation
      1. 9.1.1 Capacitor Only Isolation
      2. 9.1.2 Capacitor and Choke Isolation
      3. 9.1.3 Transformer Isolation
      4. 9.1.4 Design Summary
    2. 9.2 Ring Communication
    3. 9.3 Reclocking
      1. 9.3.1 Design Summary
  13. 10Multidrop Configuration
  14. 11Main ADC Digital LPF
  15. 12AUX Anti Aliasing Filter (AAF)
  16. 13Layout Guidelines
    1. 13.1 Ground Planes
    2. 13.2 Bypass Capacitors for Power Supplies and References
    3. 13.3 Cell Voltage Sensing
    4. 13.4 Daisy Chain Communication
  17. 14BCI Performance
  18. 15Common and Differential Mode Noise
    1. 15.1 Design Consideration
  19. 16Summary
  20. 17References
  21. 18Revision History

5.2 Typical Connection

When the bus bar connected to BBP or BBN, this allows for a single cell channel (VC channel) to be shared with a cell and a bus bar (see Figure 5-3). Usually, such a connection introduces additional IR error to the cell measurement to the system. The dedicated bus bar channel through BBP or BBN supported in the device allows the host to measure the bus bar voltage to obtain the actual cell measurement.

The connection in Figure 5-3 applies if the bus bar is connected to any middle VC channel. That is, in a single device, there is a cell connected above and below the BBP or BBN channel. To support hotplug on the bus bar channel, the device only requires a 400Ω filter resistor each on BBP or BBN pins and a 0.47µF/16V differential capacitor across BBP or BBN pins.

BBP or BBN Connection With Bus Bar Connected in any Middle VC Channel
Note: TI recommends to add 470nF/16V from CB16 to BAT for hotplug robustness not shown in above figure. See the data sheet for details.
Figure 5-3 BBP or BBN Connection With Bus Bar Connected in any Middle VC Channel

If the bus bar connected to BBP or BBN is placed at the top of a module (see Figure 5-4), then this connection is the exception in the BBP/N case that a cell channel is NOT being shared. In this connection, actual cell measurements are made through the VC channels and the host does not require performed addition calculation.

The connection in Figure 5-4 applies if the bus bar is connected to the top of the module, where in a single device, no cell is connected above the bus bar. To support hotplug on the bar channel, besides the 400Ω filter resistor each on BBP or BBN pins and a 0.47µF/16V differential capacitor across BBP or BBN pins. If the bus bar is used above the top cell, then an additional 0.47µF/16V differential capacitor is needed to connect from BBN to the top CB pin. This additional capacitor forms a complete capacitor ladder from all the cells in the module to the bus bar, allowing high spike voltage during hotplug to distributor across the capacitor ladder.

BBP or BBN Connection With Bus Bar Connected Above Top of a Module
Note: TI recommends to add 470nF/16V from CB16 to BAT for hotplug robustness not shown in figure. See theBQ79616-Q1, BQ79616H-Q1, BQ79614-Q1, BQ79612-Q1 Functional Safety-Compliant Automotive 16S/14S/12S Battery Monitor, Balancer and Integrated Hardware Protector data sheet for details.
Figure 5-4 BBP or BBN Connection With Bus Bar Connected Above Top of a Module