Serial Communication Problem with ADM3251

Hi Keval,

If Vcc is 5V, the integrated DC-DC converter is enabled meaning Viso should not be powered externally. You only need to power Viso externally if the voltage applied to Vcc is within the 3V to 3.7V range, as the integrated DC-DC converter will be disabled.

From my interpretation, it sounds as if you are powering Vcc with 5V and powering Viso externally with 5V?

You can find the Vcc and Viso pin descriptions in Table.8 of the datasheet which explain this, and you can reference Figure 14 from the datasheet which shows a typical operating circuit with the DC-DC converter enabled. Note that Viso pin should not be used to power external circuitry.

https://www.analog.com/media/en/technical-documentation/data-sheets/ADM3251E.pdf

There's also a user guide you can follow which will step you through the process of setting up the evaluation board:

https://www.analog.com/media/en/technical-documentation/user-guides/UG-120.pdf

Let me know if this solves your issue or if it persists,

Best Regards,

Shane

Hello Shane,

Thanks for the clarification. I replaced my connections and it is working ok now. Thanks for the assistance. 

I have one more question regarding the usage of the RS232 cable. Can I eliminate the DB9 connector and directly solder my wire for serial communication? Does it have any cons?

Hi Keval,

Apologies for the delayed response. 

I would expect no issues with this, as the data rates are quite low.

This could cause signal integrity issues for example, if the data rates involved were much higher.

Best Regards,

Shane

Thanks Shane,

That helps a lot, I appreciate it.