ZHCS926C May 2012 – May 2021 BQ34Z100
PRODUCTION DATA
The gas 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 low-side protector FETs (if present) or the sense resistor. It is important that the low-current ground systems only connect to the BAT(–) 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 10-1, the green is an example of using the low-current ground as a shield for the gas gauge circuit. Notice 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.