CC3220MODA: The influence of the long transition of VBAT1 on CC3220MODA

Nomo

Part Number: CC3220MODA

Hello,

Please image that nRESET is generated by connecting VBAT_RESET and VBAT1 (nRESET is generated internally) on CC3220MODA.
In case the ramping transition time of VBAT1 is very long (e.g. 10ms from 0V to 3.3V), the functionality of internal RC filter may not work normally, and then nRESET ramping time will be the same as the ramping of VBAT1 (the timing of both signals are simultaneous).

Although the nRESET signal should be low while supplies are ramping up, what happens in the above case?
Or, is there any transition time constraint of VBAT1?

Best Regards,
Nomo

over 4 years ago

0 Vincent Rodriguez over 4 years ago

TI__Mastermind 28285 points

Hi Nomo,

Can you attach the image?

Thanks,

Vince

0 Nomo over 4 years ago in reply to Vincent Rodriguez

Guru 16800 points

Hi Vince-san,

Could you confirm the attached file?

nRESET_timing.pdf

Best Regards,
Nomo

0 Vincent Rodriguez over 4 years ago in reply to Nomo

TI__Mastermind 28285 points

Hi Nomo,

Thanks for the PDF, the issue is clear. Why is the VBAT ramping at the slow pace? Is there any way in your system to increase the speed at which you ramp?

Since this would violate one spec, I can't tell you for certain whether this would work or not - You would have to internally validate. Perhaps you can reduce the RC time on the reset with additional RC components?

BR,

Vince

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CC3220MODA: The influence of the long transition of VBAT1 on CC3220MODA