SN74AVC16T245: SN74AVC16T245 application

Nanfang Liao

Intellectual 2085 points

Part Number: SN74AVC16T245
Other Parts Discussed in Thread: TXB0108

Hello team,

My customer use this part for 25M signal level shift. When DIR signal change from low to high, there is ring of DATA signal. So you think it is OK? Can our part be used for 25M? thanks

over 9 years ago

0 aozer over 9 years ago

TI__Mastermind 31865 points

Hello Nanfang,

There should be no problem running at 25MHz. I am assuming that B port is acting as the input in this screenshot. Is this correct? So, basically, B input is being held high when the direction pin is switching?

0 Patrick Simmons over 9 years ago

TI__Mastermind 26335 points

Hello Nanfang,

Perhaps this is a board layout issue. Are the customer's traces leading to these pins long and running parallel to each other?

0 aozer over 9 years ago

TI__Mastermind 31865 points

Hello Nanfang,

When doing some testing in the lab I noticed a lot of noise and distortion when switching the direction pin with OE enabled. I think the only way to really get rid of the ringing is to ensure that OE is disabled when switching the DIR pin, as this seemed to remove any noise for me.

I would suggest that a better solution to this problem would be to use two TXB0108 instead as these devices weren't really intended to be used with high speed switching of the DIR pin.

0 Nanfang Liao over 9 years ago in reply to aozer

TI__Intellectual 2085 points

Hello Aozer,

Thanks, i will double check with customer if they can redesign thier board.

Regards,

Nanfang

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SN74AVC16T245: SN74AVC16T245 application