Connect 2 Ethernet PHYs with different supply voltage

[mohsenhaghighat]

Hi.

I am working with KS8999 as switch. I want to connect it with a Ethernet phy from backplane, The KS8999 Analog Voltage is 2Volt and Ethernet PHY voltage is 2.5Volt. I am confused.

Any body can help me about these connections? can I connect these interface to each other?

[r8070z]

Have a great day,

The ks8999 data sheet
http://ww1.microchip.com/downloads/en/DeviceDoc/ks8999%20Data%20Sheet.pdf
says " Single 2.0V power supply with options for 2.5V and 3.3V I/O" and we can see special pins for I/O power in the Pin Description table "VDD-IO Pwr 2.0V, 2.5V or 3.3V for I/O circuitry". So ks8999 I/O can be connected to the device with 2.5V interface.

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[mohsenhaghighat]

Thanks Serguei,

I know that KS8999 can work with 2.5Volt. But I design a daughter board that connect with the main board. In main board I have ks8999 and I cant change it.

If I connect a 2.5Volt ethernet PHY to a 2Volt ethernet PHY, does it working? How connect them without magnetic?