SLUUCV6 June 2024 BQ2969
The BQ2969 cell count is reduced by shorting unused cells, normally from the top down but cells between the top and bottom can be shorted. The inputs are usually shorted at the IC as shown in the data sheet. The bottom cell must be used for proper operation. Power for the IC comes from the BAT+ terminal so power must be connected when using the EVM. While not recommended, the inputs of the EVM can typically be shorted at the terminal block for quick evaluation. For the best transient environment and to match the data sheet example, short the VCx pins at the capacitor and remove the unused input resistor. When using the cell simulator, shorting the unused cell at the terminal block is still required to eliminate the simulated cell voltage. Shorting the cell inputs at the terminal block screw terminals is also suggested since shorting the cell inputs is a visual indication that the device is configured for a different cell count. While different connections are possible, Table 3-1 shows configuration recommendations for reduced cell counts.
Unused Cell (Numbered from Bottom Cell 1) | Short Cell Input Terminals | Input Resistor to Remove | Replace Capacitor with 0Ω | IC Inputs Shorted |
---|---|---|---|---|
Cell 4 | BAT+ to CELL3 | R4 | C6 | VC4 to VC3 |
Cell 3 | CELL3 to CELL2 | R7 | C7 | VC3 to VC2 |