ISOW1412: ISOW14xx device for half-duplex

Jade Han

Part Number: ISOW1412
Other Parts Discussed in Thread: ISO1500,

Tool/software:

Hello team,

My customer is currently using Half-duplex RS-485 for their system, and they are interested in isolated RS-485 for some of the A/C models with many noise issues.

I introduced them ISO1500, but they were looking for a device with isolated power, so I hoped to promote our ISOW1412.However, I see that this device is a full-duplex device.

Do we have any half-duplex device with integrated isolated power?

If not, could customer still use this device? Or, should they use ISO1500 + Isolated DC/DC for half-duplex applications?

The reason why I hoped to introduce ISOW1412 was because customer's concern is that Isolated DC/DC would have switching noise..

Thank you in advance for your help.

6 days ago

+1 Clemens Ladisch 6 days ago

Guru 298340 points

The ISOW1412 can be used with a half-duplex bus (just short the driver and receiver pins); see sections 10.4 and 11.1 of the datasheet.

+1 Varun Kumar 6 days ago

TI__Intellectual 1965 points

Hi Jade,

Thanks for reaching out and promoting ISOW1412 for the customer application. Please find my inputs below:

Jade Han said:
Do we have any half-duplex device with integrated isolated power?

No, we don't have a separate half duplex device with isolated power. The existing full-duplex device itself can support the half duplex operation.

Jade Han said:
could customer still use this device

Yes, they can. Half-duplex can be achieved by shorting Y/Z to A/B pins on the half duplex bus lines. Please refer this FAQ to understand the mechanism better: (+) [FAQ] ISO1452: [FAQ] How to configure a RS485 Full-duplex transceiver as Half-duplex? - Isolation forum - Isolation - TI E2E support forums

Regards

Varun

0 Jade Han 5 days ago in reply to Varun Kumar

TI__Intellectual 1180 points

Hi Varun,

Thank you so much for your feedback!

Best regards,
Jade