LM74700-Q1: EMI Issue and solve solution double check

Songzhen Guo

Part Number: LM74700-Q1

Hi expert,

LM74700-Q1 was used in BMS for one customer. Now they have a issue for EMI;

When we test the EMI, there is a 50M noise for CE(Conduct Emission) around 200MHz. After read the datasheet of LM74700-Q1, there is a charger pump integrated inside. Could you share the inside block and frequency for charger pump? Thansk.

If you can't public the inside block diagram. You can send a Email to me. Thanks.

We also solved the EMI issue, we add a capacity like below, Is there any risk? Could you check it for us? I appreciate it if you can help. Thanks.

Best Regards

Songzhen Guo

over 4 years ago

0 Rakesh over 4 years ago

TI__Guru** 105361 points

Hi Guo,

I will check with the team for details on charge pump frequency. Please email me for that.

Usually, we won't suggest to place C46 cap in the system. I will check on the other options and get back by mid of next week.

~Rakesh

0 Songzhen Guo over 4 years ago in reply to Rakesh

TI__Intellectual 2840 points

Hi Rakesh,

Thank you so much for your suggestion.

Could you share your full name with me? So I can sent email to you, Thanks.

Here is the CE test result for LM74700-Q1:

Best Regards

Songzhen Guo

0 Rakesh over 4 years ago in reply to Songzhen Guo

TI__Guru** 105361 points

Hi Guo,

I am checking with design team. Will reply to your email ID by mid of this week.

~Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru** 105361 points

Hi Guo,

No issue in using C46 cap in the system. For other questions, I am following up on email.

~Rakesh

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LM74700-Q1: EMI Issue and solve solution double check