i.MX Processorsのトピックmini-SAS Connections reverse?

mini-SAS Connections reverse?

harsh_mistry — Wed, 22 Jul 2020 13:28:35 GMT

In our custom board design with i.MX8DualXPlus / i.MX8QuadXPlus,

We are going to use external adaptor IMX-LVDS-HDMI(935358716598) for sending the video signal over to HDMI monitor. On schematic observation, we see that the connections for the 36 pin mini-SAS connector on the main cpu board (MEK MCIMX8QXP-CPU) and on the adaptor are reverse as shown in the image here:

1. Is this connection intentionally done to compensate the connection reversal that happens in the mini-SAS cable as shown here:

2. Our main question is if we select the right angle connector (Molex #75783-0140) for our custom board and cable (Molex #795762103), will this work with the same pin connections?

Your timely response will be highly appreciated.

Regards,

Harsh

Re: mini-SAS Connections reverse?

weidong_sun — Thu, 23 Jul 2020 04:23:38 GMT

Hello Harsh,

See below, please!

1. The signals on Mini SAS are customized and non-standard.

2. For your design, you need to refer to the signal definition method on EVK.

3. For the signal definition of the Right Angle connector, please see the picture below.

OLED connector：

Hope these pictures for connections are help to you!

Have a nice day!

B.R,

weidong

Re: mini-SAS Connections reverse?

harsh_mistry — Thu, 23 Jul 2020 05:13:50 GMT

Thank you for the reply but looks like this is a bit different than what we are planning to use.

We will be using the LVDS To HDMI daughter board from NXP.

We only wish to change the vertical mini-SAS connector on the MEK (with connections shown before) to a right angle connector on our custom board (Molex #75783-0140) (similar to the daughter board) somewhat like this:

The pin connections and current connector part# on MEK are shown here:

So we still have the same question as posted earlier.

Regards,

Re: mini-SAS Connections reverse?

weidong_sun — Thu, 23 Jul 2020 12:41:25 GMT

Dear Harsh,

Here is my understanding for the connection, for you reference :

Hope it is helpful to you!

Have a nice day!

B.R,

Weidong

Re: mini-SAS Connections reverse?

harsh_mistry — Fri, 31 Jul 2020 10:01:11 GMT

Thank you for the response.

One more thing we would like to ensure is the cable length.

We are going to use Molex# 795762103. It is 600mm in length.

Can this affect the LVDS signal integrity?

What kind of measures do we have to take to ensure proper video signal transmission?

Regards

Re: mini-SAS Connections reverse?

weidong_sun — Mon, 03 Aug 2020 01:17:51 GMT

Hello Harsh,

I don’t have specific data here for you to refer to, but according to my experience, for LVDS signals, the distance of 60cm is not long and there should be no problem.

Have a nice day!

B.R,

Weidong