SLVAE87A December   2020  – October 2023 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/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 Re-Clocking
      1. 9.3.1 Design Summary
  13. 10Multi-Drop 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. 16Revision History

5.2 Typical Connection

With the bus bar connected to BBP/BBN, it is intended to allow a single cell channel (VC channel) to be shared with a cell + a bus bar (see Figure 5-3 connection). Usually, such a connection introduces additional IR error to the cell measurement to the system. The dedicated bus bar channel through BBP/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/BBN channel. To support hotplug on the bus bar channel, the device only requires a 400-Ω filter resistor each on BBP/N pins and a 0.47-µF/16-V differential capacitor across BBP/N pins.

GUID-E9A04FB4-9530-4079-866B-EC8CA33AA545-low.jpg
Note: New recommendation to add 470 nF/16 V from CB16 to BAT for hotplug robustness not shown in above figure, see data sheet for details.
Figure 5-3 BBP/N Connection With Bus Bar Connected in any Middle VC Channel

If the bus bar connected to BBP/N is placed at the top of a module (see Figure 5-4 connection), such 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 400-Ω filter resistor each on BBP/N pins and a 0.47-µF/16-V differential capacitor across BBP/N pins. If the bus bar is used above the top cell then also an additional 0.47-µF/16-V 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.

GUID-6859FD3D-C701-4ABF-8863-CCDE584261E0-low.jpg
Note: New recommendation to add 470 nF/16 V from CB16 to BAT for hotplug robustness not shown in figure, see data sheet for details.
Figure 5-4 BBP/N Connection With Bus Bar Connected Above Top of a Module