Possible Short-Circuit during Boot-Sequence

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marss
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Possible Short-Circuit during Boot-Sequence

On a Custom-PCB the OTP is in its default state. This means e.g. that the "Production Ready" flag is not set an that the DA14683 goes through it's boot sequence and configures various pins as outputs. This could potentially damage some devices, especially because the DA14683 can be used to power other components which may not yet fully running (e.g. until 1V8 is configured properly).

But more important: I assume this could also damage the DA14683 itself? What is the recommended procedure from Dialog?

Keep the DA14683 in reset and hoping that a debugger is fast enough to connect before the boot sequence starts? Or is the boot sequence fast enough that this will not lead to an issue, even if a pin may (indirectly) be connected to GND?

Device: 
PM_Dialog
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Hi marss,

Hi marss,

My apologies, but could you please try to explain what the issue is?  Any other information that you can share it would be very helpful in order to understand the problem.

Thanks, PM_Dialog

marss
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Last seen: 4 months 2 weeks ago
Joined: 2015-05-08 10:18
Hello,

Hello,

Our problem is that on most of our custom PCBs the current which goes through the DA14683, is too high when turning on the power (> 20mA).

One question we were asking ourself is if the boot sequence could be part of the problem. The DA14683 goes through his boot sequence as long as the OTP is not written yet (which happens on every custom PCBs for the first time, until the OTP is programmed). If one of the pins, which the boot sequence configures, has an almost zero resistance there may be a short circuit on the DA14683 itself. The reason this could happen is because the DA14683 gives power to other devices, which not be fully intialized while the DA14683 already goes through its boot sequence. Beside that this could damage other external components, it also could damage the DA14683 itself.

 

 

PM_Dialog
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Last seen: 2 days 9 hours ago
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Hi marss,

Hi marss,

My apologies for my late response – probably I missed your last comments. Sorry but I cannot understand why this procedure could damage the DA14683. So, if I am not mistaken, you are using the DA14683 to power up some peripherals components. Is that correct? Did you program that OTP and boot from there?

Thanks, PM_Dialog

PM_Dialog
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Last seen: 2 days 9 hours ago
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Joined: 2018-02-08 11:03
Hi marss,

Hi marss,

Sorry again for the delay. We will take this ticket offline from the forum.

Thanks, PM_Dialog