SLUSF21 june 2023 BQ79616
PRODUCTION DATA
The BBP and BBN pins are the inputs for bus bar measurement from the Main ADC. The intent of the BB channel is to enable the system to share a bus bar with a cell to a single VC channel, as the example shows in Figure 8-5. Hence, similar to the VC inputs, the BBP/N inputs also have the BCI, Level-Shifters, and AAF filters in the front end. The differential BB channel measurement also has an option to pass-through a post-ADC digital LPF. With the same fcutoff option as for the VC channel by using different configuration and enable control, ADC_CONF1[LPF_BB2:0]and ADC_CTRL1[LPF_BB_EN].
The BB channel measurement is reported in the BUSBAR_HI (high-byte) and BUSBAR_LO (low-byte) registers. If the digital LPF is disabled, the result registers are reported with the single ADC conversion value; otherwise, the result is reported in the filtered measurement value. In Figure 8-5, to obtain the actual Cell6 measurement, the MCU takes the difference of (VCELL6_HI/LO measurement – BUSBAR_HI/LO measurement). If the BBP and BBN pins are not used (floating), the BUSBAR_HI/LO register values are meaningless. The MCU will ignore these register values.