I'm curious why the Absolute Maximum Rating for VSYS is the same as the Recommended Operating Conditions maximum. Shouldn't the Absolute Maximum Rating be a little bit higher than the Recommended maximum (5.5V)? I'm not in control over the voltage supplied to my product. Someone could hook up a supply that is slightly higher than 5.5V and I wouldn't want the DA9062 to perish. I think over-voltage protection devices typically clamp at about 5.7V to allow for a 10% variation on a 5V supply. It would be great if it could handle 5.7V without an issue.
I intend to use one supply for both VSYS and the regulator VDD supplies. The block diagram of a typical application (page 32 of the datasheet) does not show the supplies being connected to each other. Would it be not recommended to use one supply for both?
Thank you and regards,
ElectronHerder
Hello Electronherder
The fabrication process limits us to 5.5V absolute maximum rating for Vsys. However this is conservative, as this is the process maximum specification for long-term reliability. Therefore, the process can be run for short instances at higher voltages. However, Dialog has been conservative in specifying the absolute maximum as 5.5V.
Dialog has performed extensive studies of the Safe Operating Area (SOA), as this is critical to reliable buck operation at the LX nodes. From the info sent by email, you can see that the instantaneous breakdown voltage for the fab process is much higher than 5.5V. This illustrates the expected behaviour for transients of up to 5.7V and greater.
Connect the bucks to the same supply as Vsys.
I will send across more information in a direct email.
Kind regards,
Elliott Dexter
Thank you Elliot. That is excellent. It makes sense, and now I will rest easy knowing that it isn't super critical to limit it to 5.5V. A clamp at 5.7V will be a single event and not as bad as the repeated voltage spikes seen at the LX nodes.
I appreciate your help in answering this question. This forum topic is now complete.
Kind regards,
ElectronHerder