ZHCSF78E June 2016 – April 2019 BQ35100
PRODUCTION DATA.
The fuel gauge requires a low-current ground system separate from the high-current PACK(–) path. ESD ground is defined along the high-current path from the Pack(–) terminal to the sense resistor. It is important that the low-current ground systems only connect to the PACK(–) path at the sense resistor Kelvin pick-off point. It is recommended to use an optional inner layer ground plane for the low-current ground system.
In Figure 16, the green is an example of using the low-current ground as a shield for the gas gauge circuit. Note how it is kept separate from the high-current ground, which is shown in red. The high-current path is joined with the low-current path only at one point, shown with the small blue connection between the two planes.