I don't believe it does.Main cause of damage is separately powered devices that connect to the processor and are not powered at the same time.
Gerald On Wed, Dec 21, 2016 at 7:26 AM, Jason van Belzen <[email protected]> wrote: > Thanks for your reply. > > How does this issue damage the processor? > > Jason > > Op woensdag 21 december 2016 14:08:47 UTC+1 schreef Gerald: >> >> I have no plans to fix this. If you need battery operation, which the BBB >> does not really support as it needs 5V for the USB, then you need to modify >> the board design for your usage. >> >> Gerald >> >> On Wed, Dec 21, 2016 at 7:03 AM, Jason van Belzen <[email protected]> >> wrote: >> >>> 3v3 regulator bug: >>> >>> https://groups.google.com/forum/#!msg/beagleboard/7sxPePT7wk >>> M/3vFMPydR20IJ >>> >>> The issue is the interconnection of the 3v3a and 3v3b power domains, >>>> resulting in significant leakage current between them (e.g. via protection >>>> diodes) whenever one is powered while the other is not. The 3v3b -> 3v3a >>>> leakage was of course exactly the reason for moving the enable-signal of >>>> the 3v3b regulator (U4) from 3v3aux (LDO2) to 3v3a. However, while this >>>> resolved the issue at boot, it did not resolve it at shutdown when running >>>> on dc power, and made it far worse when running on battery. >>>> >>>> The problem is that when the 3v3a supply (LDO4) is disabled, the 3v3b >>>> regulator remains enabled until 3v3a drops below the threshold voltage of >>>> the enable-input of U4, which is far below 3.3V (specified to be somewhere >>>> between 0.4V (at 25 ͏°C) and 2V). As a result, current will start to flow >>>> from 3v3b to 3v3a, and apparently enough current to keep it logic-high in >>>> the opinion of the 3v3b-regulator (despite the ~375 ohm discharge resistor >>>> the PMIC applies when LDO4 is disabled!). >>>> >>>> Thus, once turned on, the 3v3b regulator manages to keep itself enabled >>>> indefinitely as long as it is supplied from SYS_5V. When entering >>>> off-state, the PMIC automatically connects SYS to battery power rather than >>>> DC- or USB-supply. If there's no battery, then the capacitors on SYS will >>>> drain pretty fast hence the 3v3b shutdown is not delayed much. If there's a >>>> battery, then you're pretty screwed. >>>> >>>> It is very important to note that this issue is not merely one of >>>> battery lifetime; this leakage current may *damage the processor*. >>>> >>>> >>> >>> Op woensdag 21 december 2016 13:55:57 UTC+1 schreef Gerald: >>>> >>>> And what is the 3.3V bug? >>>> >>>> Gerald >>>> >>>> >>>> On Wed, Dec 21, 2016 at 6:54 AM, Jason van Belzen <[email protected] >>>> > wrote: >>>> >>>>> Hi, >>>>> We are planning to build an IoT gateway based on a Beagle Bone Black. >>>>> Till now we were experimenting with the Beagle Bone Black Rev C. >>>>> Since we need to protect the filesystem, we want to use a battery so >>>>> we can detect a power failure and nicely shutdown the system. >>>>> >>>>> Unfortunaletly we encountered a problem. >>>>> After shutting down the system with a battery connected, the 3v3 >>>>> regulator bug is triggered. >>>>> The BeagleBone Black is a good board for our purpose, so we really >>>>> want to use this board. >>>>> >>>>> A few questions come up in our minds. >>>>> 1. How bad is this bug? Is it really gonna damage the processor? >>>>> 2. Are there any other solutions than patching to an unified 3v3 rail? >>>>> 3. Are there any next revisions planned for the BeagleBone Black? And >>>>> if they are planned, will this bug be fixed in the next revision? >>>>> >>>>> Thanks. >>>>> >>>>> Regards Jason >>>>> >>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "BeagleBoard" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/beagleboard/a3dea840-c1cf- >>>>> 4dad-a0dc-b19ba9936504%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/beagleboard/a3dea840-c1cf-4dad-a0dc-b19ba9936504%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> >>>> >>>> -- >>>> Gerald >>>> >>>> [email protected] >>>> http://beagleboard.org/ >>>> [email protected] >>>> >>>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit https://groups.google.com/d/ms >>> gid/beagleboard/bbbedc74-a881-4c4e-84f5-0897b8ea8372%40googlegroups.com >>> <https://groups.google.com/d/msgid/beagleboard/bbbedc74-a881-4c4e-84f5-0897b8ea8372%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Gerald >> >> [email protected] >> http://beagleboard.org/ >> [email protected] >> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/beagleboard/f4612892-76f9-4d83-bdbd-8072af11b172%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/f4612892-76f9-4d83-bdbd-8072af11b172%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Gerald [email protected] http://beagleboard.org/ [email protected] -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BfKKOC17qAsQ2AGVsYkD2RS23zAhy9_BDvbfLxhxYx55Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
