Texas Instruments bq76920EVM, Руководство пользователя, Страница: 23 / 46

See table for
reduced cell
configuration
3 cells shown
Short C4 to C3
and C3 to C2
Simple evaluation,
allows easy cell
count change but
leaves parallel paths
to IC
Cell simulator switches on
DC Power Supply
+ -
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bq76920 Circuit Module Use
23 SLVU924D – March 2014 – Revised November 2018
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bq76920 Evaluation Module User's Guide
Table 3. Reducing Cell Count
Unused Cell
(Numbered from Bottom Cell 1)
Short Cell Terminals Input Resistor to Remove Short AFE Inputs
Cell 4 C4 to C3 R5 VC4 to VC3
Cell 3 C3 to C2 R6 VC3 to VC2
When evaluating the gauge, it is recommended to reduce the cell count of the gauge configuration before
connecting the cells. If the gauge does not see voltage it will shut down the AFE and require re-boot of the
board. To avoid shutdown simulate a charge current until the cell count configuration can be corrected.
Figure 18. Example 3 Cell Simple Evaluation Configuration
6.4 Connecting Cells
The EVM is constructed to sense the cell voltages at the cells. Separate wires are required from the
bottom of the battery stack to the C0 connection at the terminal block for sensing voltage and from the
bottom of the battery stack to the BATT– terminal to carry the load current. The AFE IC VSS is referenced
to the BATT– connection. Similarly, separate wires are required from the top of the battery stack to the top
cell input of the terminal block and from the top of the battery stack to the BATT+ terminal to carry the
load current. The top cell sense connection also powers the AFE IC. To move the sense connections from
the cells to the board, populate R1 and R2. The bottom cell simulator switch can be closed to connect C0
to BATT–.