ISO6742-Q1: ISO6742D using it for bidirectional pin

Vasu Poojary

Other Parts Discussed in Thread: ISO6742, SN74LVC1G125

Tool/software:

Hello ,

We have a digital bidirectional pin which has to isolated using ISO6742D , Is below configuration is fine to use ? (We already have ISO6742 in our design and want to use same )

Is these pins has influence on other pins ?

EN/Fault pin is digital pin form IC which has to sensed and controlled from MCU with isolation , when Fault condition is sensed it will sensed thorough out channel of isolator by MCU.

MCU can reenable the chip through input pin of isolator .

does these pin has cross functional effect in this case ?

comment on any other boarder condition where this has impact.

Thanks

Regards

Vasu

2 months ago

0 Varun Kumar 2 months ago

TI__Expert 7325 points

Hi Vasu,

Today 4th July is a US Holiday.

We will evaluate your inputs and reply by July 8th.

Regards
Varun

0 Clemens Ladisch 2 months ago

Guru 316440 points

This will not work because the OUTC pin is always active. You have to transmit two signals through the isolator (e.g., OUTC and OUTD) and control a three-state buffer like the SN74LVC1G125 with them.

0 Vasu Poojary 2 months ago in reply to Clemens Ladisch

Intellectual 440 points

Hello

Can you please elaborate more on using (OUTC and OUTD) and tri-state buffer ?

thanks

Regards

Vasu

0 Aaditya V. 2 months ago in reply to Vasu Poojary

TI__Genius 17295 points

Hi Vasu,

Thanks for reaching out.

The ISO6742 is not meant for bidirectional use of channels. In order to use the isolator for bidirectional use, more components will be required than simply directly connecting the OUTC and INB pin. Please check this document for a breakdown on setting up channels for bidirectional use: Designing an Isolated I2C Bus interface by using digital isolators (Rev. A)

Additional to this, this E2E post seems similar to your application: ISO6763-Q1: Difference between ISO7763 and 6763 - Isolation forum - Isolation - TI E2E support forums

Regards,
Aaditya V