TXS4555: TXS4555 in long trace application

Penn Zhang

Part Number: TXS4555
Other Parts Discussed in Thread: SN74AXC2T45

Hi Sir,

In customer application, LTE 4G module SIM trace is long to 10000mil(254mm), the max requirement is 150mm, do you think if I add one TXS4555 is workable?

Thank you.

Penn

over 4 years ago

0 ShreyasRao over 4 years ago

TI__Guru 58620 points

Hi Penn,

TXS4555 doesn't have the CLK frequency support for 4G LTE module( up to 25Mhz) . Please check the requirements if TXS4555 would work.

TXS4555 has weak drive strength similar to the other TXS family. The internal pullup resistors enable the translation in the TXS4555 IOs.

The CLK, RST have active drivers with +/-1mA current drive.

0 Penn Zhang over 4 years ago in reply to ShreyasRao

TI__Intellectual 1180 points

Hi Shreyas,

Yes, you are right, 4G LTE Modele CLK is 26MHz, so I think part can't meet this requirement.

Have you ever seen some part that could work in this application? do you have any recommendations for this?

Thanks.

Penn

0 ShreyasRao over 4 years ago in reply to Penn Zhang

TI__Guru 58620 points

Hi Penn,

As per the datasheet, yes, it cant meet the spec. But the spec is rated at 50pF cap load and if the loading on the PCB is smaller, then 26Mhz is a possibility.

but as I mentioned earlier, the TXS4555 doesn't provide drive strength for the IO pins.

0 Penn Zhang over 4 years ago in reply to ShreyasRao

TI__Intellectual 1180 points

Hi Shreyas,

Got you.

Do you have any recommended device for this application?

Thank.

0 ShreyasRao over 4 years ago in reply to Penn Zhang

TI__Guru 58620 points

Hi Penn,

For the CLK and RST channels, SN74AXC2T45 can support 26 MHz and drive long traces because of its active drive circuitry.

As the data lines are bidirectional, AXC family cannot work. You may have to consider going with I2C re-drivers but I see the max freq is still a limitation.

If the data line can be DIR controlled, then AXC1T45 will work.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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TXS4555: TXS4555 in long trace application