CC2541: CC2541 goes dead after frequently power on

dsp999

Part Number: CC2541

test a CC2541 board, power on and off every 1 second, like a user plugs on/off the device to power connector, then, several minutes later, it goes dead.

I read out the hex from the chip, find it is different from the hex at first (before dead).

the software has comment out flash read/write, so no flash read/write in software. (at least in application level, do not know low level bluetooth stack).

how to solve this problem?

over 5 years ago

0 dsp999 over 5 years ago

Expert 1495 points

left picture is bad hex, many zeros.

0 Fredrik K over 5 years ago in reply to dsp999

TI__Guru** 106705 points

Hi,

This sounds very strange. Are you saying that after cycling power several time, the device operates normally for several minutes and then goes dead? And you then see large areas of flash written to 0?

Is this repeatable? Is the affected flash area always the same? What HW are you running?

Regards,
Fredrik

0 dsp999 over 5 years ago in reply to Fredrik K

Expert 1495 points

yes, works normally for some time, not more than a hour and then dead, read out hex has large area of 0. repeatable, we have tested several boards many times. will check whether it is the same area. hardware is a minimum bluetooth system, with several IO drive relays.

0 dsp999 over 5 years ago in reply to dsp999

Expert 1495 points

this is another sample, shows different area problem, some 0, some FF

0 Fredrik K over 5 years ago in reply to dsp999

TI__Guru** 106705 points

Can you share your HW design?

0 Fredrik K over 5 years ago

TI__Guru** 106705 points

Layout?

0 Fredrik K over 5 years ago

TI__Guru** 106705 points

Hi,

I cannot open pcbdoc. Please provide Gerber files.

Regards,
Fredrik

0 Fredrik K over 5 years ago

TI__Guru** 106705 points

I am not able to access that link. Can you just post a picture here on the forum?

0 dsp999 over 5 years ago

Expert 1495 points

see?

0 Fredrik K over 5 years ago

TI__Guru** 106705 points

I cannot open the bottom layer, the only file I can open on the bottom side is the paste mask.

Anyways, there are several major issues with the design with could lead to unexpected operation.

Grounding is very poor:
- The ground pad only has one via, the reference designs calls out 16
- Decoupling caps ground return path to the IC is close to none-existent. Look at the ground connections for C4 and C5 for example.
- C25 ground loop to the LDO is very bad.

Several power pins are missing local decoupling.

I would recommend that you re-spin the layout, closely following the reference designs.

Regards,
Fredrik

0 dsp999 over 5 years ago in reply to Fredrik K

Expert 1495 points

thank you very much. I will follow your suggestions.

0 dsp999 over 5 years ago in reply to dsp999

Expert 1495 points

would you please do me a favor to delete my posts which have sch (jpg) and pcb files?

0 Fredrik K over 5 years ago in reply to dsp999

TI__Guru** 106705 points

I have deleted all the posts with design files. Let me know if I missed any.

Regards,
Fredrik

0 dsp999 over 5 years ago in reply to Fredrik K

Expert 1495 points

we have made a new board and testing. another issue found is, when finger touch crystal oscillator, the board (chip) will go dead. please kindly give some suggestions, which points to notice.

0 Fredrik K over 5 years ago in reply to dsp999

TI__Guru** 106705 points

Which crystal, the 32 MHz or the 32 kHz? Crystals in general are susceptible to external influence. Typically the 32 kHz more so than the 32 MHz. Potentially if you touch the crystal you might actually stop it, in which case the IC would also halt as well.

0 dsp999 over 5 years ago in reply to Fredrik K

Expert 1495 points

thanks, could you please give me some suggestion about esd protection on antenna? we are using external antenna (not on board antenna).

0 Fredrik K over 5 years ago in reply to dsp999

TI__Guru** 106705 points

I would recommend looking at this part: www.ti.com/.../tpd1e0b04

Regards,
Fredrik

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CC2541: CC2541 goes dead after frequently power on