TMP1827: TMP1827 isolation

Hi Shachar,

I'm going to try to direct your post to our Isolation product line so that they can help guide you to the TI product that best meets your needs. However, I'm going to start by providing some information on the type of isolation solution that is needed for TMP1827's 1-Wire bus.

If you choose to implement isolation at the SDQ pin/bus level, the isolator that you select must be bidirectional as shown in orange here.

If you can implement isolation at the controller, you could design your controller with two unidirectional isolators as shown in orange here.

Note that while I've annotated art work that shows GPIO and UART implementations, as well as bus-powered vs supply-powered implementations, these features are all interchangeable. For example, you could implement a GPIO-OUT and a GPIO-IN to utilize unidirectional isolators with a GPIO implementation of 1-Wire.

thanks,

ren

Hi Shachar,

Looking at the schematic connection it looks like it can be prone to lockout condition since SDA2 and SCL2 are shorted. Remember,  both SDA and SCL are bidirectional capable channels, which means - Any Signal on UART_TX will be transmitted back to UART_RX through SDA channel.

Based on Ren's input above and my understanding, a GPIO based communication makes more sense with ISO1640. You will be needing only 1 channel, either SDA or SCL, to communicate in both directions.

Regards
Varun

Hi Shachar,

That can be 0ohm as well since you already pull ups in place and also it's optional to have.

Regards
Varun