TXB0108: Difference between TXB & TXS.

Phaniendra Kundeti

Part Number: TXB0108
Other Parts Discussed in Thread: SN74LVC8T245

Hi,

What is the difference between TXB and TXS 8-bit level translator.

We are using TXB0108 for differential signal level translation. Tx+ and Tx- are input and output is given to receiver. Rx+ and Rx- is fed to the controller through TXB0108.

When we are doing a loop back test, noise is observed in SCOPE on these lines which is effecting the loop back test. When loop back is removed and transmit line is monitored it is absoutely fine shows the character which we are transmitting.

Can TXS configuration be used to drive RS422 to a long distance since it is open drain configuration.

Can TXB or TXS be used as a differential tranceiver

Regards,

Phaniendra Kundeti

over 5 years ago

0 ShreyasRao over 5 years ago

TI__Guru 55960 points

Hi Phaniendra,

The FAQ has the comparison for the 3 auto bidirectional translators.

e2e.ti.com/.../3568.03-txb-devices

TXS is recommended for open drain communication. however, the translators don't support true differential line transmission (+ and - levels).
what are the levels of the TX+/- and Rx-/+ ?

0 Phaniendra Kundeti over 5 years ago in reply to ShreyasRao

Intellectual 260 points

Hi Shreyas,

TXB output is connected to the load tranceiver directly. Voltage levels are +5V TTL.

Can TXB drive directly a RS422 differential line??

Regards,

Phaniendra Kundeti.

0 ShreyasRao over 5 years ago in reply to Phaniendra Kundeti

TI__Guru 55960 points

Hi Phaniendra,

TXB has a weak DC current drive (20uA) and also has limitation on the cap loading. It can work well with high-Z loads, but not with high loading requirements.
You could consider using the SN74LVC8T245 for 5V support.

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TXB0108: Difference between TXB & TXS.