ZHCSE65B August 2015 – November 2018
PRODUCTION DATA.
The bq78350-R1 device updates the individual series cell voltages through the bq769x0 at 1-s intervals. The bq78350-R1 device configures the bq769x0 to connect to the selected cells in sequence and uses this information for cell balancing and individual cell fault functions. The internal 14-bit ADC of the bq769x0 measures each cell voltage value, which is then communicated digitally to the bq78350-R1 device where they are scaled and translated into unit mV. The maximum supported input range of the ADC is 6.075 V.
The bq78350-R1 device also separately measures the average cell voltage through an external translation circuit at the BAT pin. This value is specifically used for the fuel gauge algorithm. The external translation circuit is controlled via the VEN pin so that the translation circuit is only enabled when required to reduce overall power consumption. For correct operation, VEN requires an external pull-up to VCC, typically 100 k.
In addition to the voltage measurements used by the bq78350-R1 algorithms, there is an optional auxiliary voltage measurement capability via the VAUX pin. This feature measures the input on a 1-s update rate and provides the programmable scaled value through an SMBus command.
To support large battery configurations, the voltage data can be scaled to ensure accurate reporting through the SMBus. The data reported is scaled based on the setting of the SpecificationInfo() command.