SN74CB3T3245: [Urgent] Level shifting design verify

[FAE] Andrew Wang

Genius 10685 points

Part Number: SN74CB3T3245

Hi Team,

We have an urgent case that needs SN74CB3T3245 as level shifter between AM335 (3.3V) and BRCM MAC (2.5v).

The speed requirement is at least 125MHz, for RGMII interface level shifting.

Please help to verify if my proposal looks correct?

Customer needs 6 TX and 6 RX. It's not bi-directional actually.

To be more accurate, I only need to leave pull up resistor for the receiver side, am I correct?

Thanks a lot for checking!

Andrew

over 8 years ago

0 Fan.Wang over 8 years ago

TI__Intellectual 2900 points

Hey Andrew,

I think I see the intention of your circuit. SN74CB3T3245 can do the level shifting automatically for you. Below is the right circuit connection.

The only thing I need to double check is the 125MHz bandwidth requirement. I will measure it and keep you updated.

0 [FAE] Andrew Wang over 8 years ago in reply to Fan.Wang

TI__Genius 10685 points

Hi Fan bro,

Thanks a lot. Now I understand this device can accept up to 5.5v input while VCC is lower at 2.5V. and VCC decides the output logic level. Correct me if I misunderstand

Many thanks. =)

Andrew

0 Fan.Wang over 8 years ago in reply to [FAE] Andrew Wang

TI__Intellectual 2900 points

Andrew,

You are absolutely correct.

Switches & multiplexers

Switches & multiplexers forum

SN74CB3T3245: [Urgent] Level shifting design verify