What is the part number for the 10 (2x5) pin connector on the back of the JS220 for GPIO? It looks like a Molex SL series, but the orientation key looks like it has an extra piece for connector retention.
Also, if possible, would it be possible that on a future iteration, there is a ground pin next to each IO (including Vref). I often make a twisted pair with a ground wire to improve signal integrity and reduce noise. I just did this on a 12.5MHz application, and it reduced the coupled noise quite a bit. Yes, I realize that the sample rate on the GPIO is 1M, but it was causing some spurious triggering that was being picked up.
The GPIO connector part number for the connector on the JS220 is Molex 90130-3210. This is a narrow format connector indended for cable assemblies, not board-to-board. Molex 219658-1103 is a compatible off-the-shelf cable assembly.
I definitely understand the desire for matching ground for each I/O. Unfortunately, we have already decided to keep the third-generation JS320 fully compatible with the JS220, and it will have the same connector pinout.
If I remember correctly, the 2x5 connector was widely available in this narrow format. Jumping up to 2x7 (4 in, 2 out, 1 Vref, grounds for each) required the wider board-to-board format, which did not fit. However, the JS220 was also designed during COVID shortages, so I am not sure what is actually available today. The choice was a dedicated ground and 2 IN or the existing arrangement with 4 IN.
If you only need 2 IN, you can use IN2 and IN3 which have an adjacent ground.
We will definitely consider a connector pinout with dedicated grounds per I/O for future products.
Thanks for the prompt response, and thanks for the link to the user guide. That’s a very well written guide, and I’ll make sure to look through that to answer my own questions in the future.
That’s totally fair about the decisions around the connector. I did end up using IN2/3 for my signals, as you suggested.