Hello Federico,
I suspect that the initial device damage occurs just before the device will overheat. Most often damage to the driver will cause excessive current flow and this will increase the temperature and cause more damage.
The 100 ohm resistor should be on the AB pins but not the YZ pins. The purpose of the resistor is to prevent reflections back down the cable.The AM26C31 does not have a strong resistance to ESD and EOS. If 3.3V is availble in your system I susgest using the AM26LV31E instead.It has much better ESD and EOS protection and uses less power.
If staying with the AM26C31, adding protection diodes from Y and Z to GND and VCC and a small series resistance (10 ohms) to the Y&Z outputs will make a more robust system.
Regards,Ron Michallick
Regards,Ronald MichallickLinear Applications
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Thanks for the reply.
I will consider the protection diodes and small resistances because it's not posible to use 3.3V version.
I missed an important detail. In my circuit, I'm using am26c31 and am26c32 to establish a communication beetwen two separated boards that don't share the same Ground.
Is it critical for am26c31 and am26c32 to have the same Ground?
Federico,
Yes, the ground must be common.Are the grounds connected at all and how much voltage differential in the two grounds.
Federico, try this one.
If the ground potential difference between GND1 and GND2 is large, a 100 ohms resistor helps limiting the ground current.
Otherwise you can use digital isolators to avoid ground current entirely
- Thomas
Thank you very much.