UART protection IC

Hi Roy,

Do you know how negative your signal is dropping? 

What's the max current you are expecting to see under the worst conditions?

I suspect we may be able to use some kind of clamping diode to limit the undershoots. (In the past I've used BAT54C)

Thanks,

-Bobby

Hi Bobby,

Our scenario is that the UART interface accidently connect to CAN bus. So the negative voltage may -2.5V.

Roy

Roy,

Normally when there is a negative voltage swing, you would also need to provide a max expected current value inorder to properly select a clamping diode (the clamping voltage is dictated by the max current value)

I can reassign this thread to the protection diodes group to see if they have anything in their portfolio.

-Bobby

Hi Roy,

Would the negative voltage be something you want to protect against, or is that part of normal operation?

Also, how many lines are you wanting to protect, and what is the max/min operating voltage?

Regards,

Matt Smith

Hi Matt and Bobby,

Scenario is CANH/CANL connect to RX/TX accidently. So the negative voltage will be -2.5V.

For negative current, as I know UART interface is push/pull topology, I don't have any concept of how large current will pass though the RX/TX when we connect to CANH/CANL acciednetly.

Roy

Roy,

Is this for ESD/TVS protection, or is it just for over voltage protection? 

Regards,

Matt