BQ79606A-Q1: Differential pair impedance

Hello Juan,

This is not critical for communication but we still recommend engineers to follow design criterion of differential pair.

See more details in application note-SLUA811.

Differential Communication
Maintaining signal integrity while in a stacked configuration is critical to the success of this part. In order to
maximize immunity to interfering signals there are a couple design choices that need to be made. For
transformer based communication, be sure to select a transformer that provides isolation appropriate for
the specific application so ignore point number 5.
1. Keep wires and PCB traces as short as possible. Do not exceed datasheet recommendations.
2. For any single-signal pair between two nodes (ICs), individual wires and traces should have the
same length.
3. Unshielded, twisted-pair wiring is required for any cable runs.
4. Run PCB traces in parallel, on the same layer, without any other traces or planes in between. Long
runs should avoid noisy traces and/or be stitched at intervals similar to twisted-pair wire.
5. Use high-quality capacitors for voltage isolation between ICs and place in close physical proximity
to each other as part of the parallel-track layout

Andy

Thanks Andy!