MMWCAS-RF-EVM: what will be the impact if we still use 220nF with VBGAP？

xu qingjie

Intellectual 320 points

Part Number: MMWCAS-RF-EVM

Hi supporter；

what will be the impact if we still use 220nF with VBGAP？

thanks

over 3 years ago

0 xu qingjie over 3 years ago

Intellectual 320 points

Hi supporter；

I found the description in spruit8d.pdf. But there is no explanation.

We have some MP products used 220nF with VBGAP,so we want to know the impact.

thanks

0 Cesar over 3 years ago in reply to xu qingjie

TI__Guru*** 149014 points

Please give us some time to review your request

Will get back to you early next week

thank you

Cesar

0 aozer over 3 years ago in reply to xu qingjie

TI__Mastermind 30695 points

Hello,

If you use 220nF cap on VBGAP, there can be issues with booting the device at cold temp (<0C). It is strongly recommended to update to 47nF capacitor to prevent the cold boot issue.

Regards,

Adrian

0 xu qingjie over 3 years ago in reply to aozer

Intellectual 320 points

HI Adrian；

Thanks for your reply.We are going to update to 47nF. Could you please describe more details about cold boot issues？What are those issues and how bad they are.

thanks

0 xu qingjie over 3 years ago in reply to aozer

Intellectual 320 points

Hi Adrian；

Any update？We need know the exactly reason and explain to our customer why change the bom.

thanks

+1 aozer over 3 years ago in reply to xu qingjie

TI__Mastermind 30695 points

Hello,

The value of the cap will change the delay in the Bandgap power up and subsequently all the stages of Analog/RF system power up gets delayed. Boot system checks during the power up if these values are not settled to the expected state, then device may not power up correctly.

Using the wrong cap value can cause a complete failure of the system at cold temperatures.

Regards,

Adrian

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MMWCAS-RF-EVM: what will be the impact if we still use 220nF with VBGAP？