S32K388 RGMII

[AB5]

Hi,

We want to connect the S32K388 RGMII interface to an ASIC RGMII interface in a MAC to MAC connection. 

The S32K388 RGMII is 3.3V while the ASIC is 1.8V. Any idea how to resolve this?

[PavelL]

Hello @AB5 ,

You’ll need to use level shifters. I found an interesting article on the topic: https://www.nexperia.com/dam/jcr:790eaac6-e53d-4235-a3d7-4f6330fa7009/Nexperia%20Webinar%20Lost%20in...

For RGMII (Reduced Gigabit Media Independent Interface), the level shifters must meet specific requirements:

• Low propagation delay to maintain tight timing margins (RGMII operates at 125 MHz DDR).
• Push-pull outputs (not open-drain) to support high-speed signal integrity.
• Direction-controlled or fixed-direction operation (auto-direction sensing introduces too much latency).
• Voltage translation from 3.3V to 1.8V (or vice versa, depending on PHY/SoC I/O levels).

Device like the 74ALVC164245 from Nexperia can be a good candidate.

Best regards,

Pavel