SLUSDQ4 April 2019 BQ79606A-Q1
When selecting the cabling, keep in mind that the cable adds parasitics to the system. For capacitively isolated systems, the capacitance of the cable forms a divider with the isolation capacitance. See the Capacitor Isolation (Not the same PCB) section for details. The capacitance of the cable is calculated using the equation:
The unshielded twisted cable used for bench testing (Alpha Wire 3050 series, Digi-Key part number +A2015W- 1000-ND) has the following specifications:
The resulting capacitance is ≈ 21.6 pF/ft.
The best choice of differential cable is an automotive-grade, unshielded, twisted cable designed for CAN, such as the Waytek SAE J1939/15 CAN data bus cable. The capacitance for this cable is approximately 17 pF/ft.