# Connector pinout review

I am designing a system around a bus using DIN 41612 connectors. I have come up with the following pinout for my connector taking into account the following requirements :

• Each signal pin should have a ground pin next to it for better ground return paths
• The boards is rated at 30W coming from the 12V pins of the connector.

With this design, 12V pins shouldn't exceed 625mA as each pins of the connector can handle 2A of current.

Is this a good pinout or am I missing something ?

Thanks !

• What's the speed of your signals? Single-ended or differential? I'd say this is too few ground pins by a factor of >2, but if all these signals are very low speed, we could shrug this off. Generally, you'd want a ground pin not only to be a neighbor, but the closest neighbor of a signal pin. Assuming proper decoupling, you can, however, treat your +12V as ground pin when it comes to signal integrity. Commented May 2, 2021 at 15:17
• The signals are single-ended and I'd like them to be at least 30 to 50MHz. What do you mean by the closest ? Closest as there shouldn't be any other pin as close to it ? Commented May 2, 2021 at 15:35
• closest as in "there shouldn't be another signal pin geometrically closer than the next ground or VCC pin"; in your case, there's several instances where the direct neighbor (one pitch of 2.5mm) is a signal and there's a ground diagonally adjacent, but since $\sqrt2>1$, that's not as good. Commented May 2, 2021 at 15:56
• Also consider where the grounds will be on the mating cable, if you're using a cable and not board-to-board. Ideally you'd have a ground on either side of every signal cable if using a ribbon cable, or one twisted with every signal if it's twisted pair, etc. If this is board to board, that's not a concern. Commented May 2, 2021 at 16:47
• Ok I see, so there is only an issue with the pins in the ground pins' diagonals right ? Commented May 2, 2021 at 17:15