Inquiry regarding bootstrap capacitor value on LM25101

Atsushi Okui

Other Parts Discussed in Thread: LM25101, UCC27201

Hello, all

Now we are designing our new product with LM25101.

Then would like to know your recommended bootstrap capacitor value on this device.

I could not find any description regarding this value on this datasheet. Meanwhile, I could find this description on the datasheet page12 of UCC27201, which seems to be compatible on this device, as below;

Typical range of HB bypass capacitor is 0.022 uF to 0.1 uF, the value is dependant on the gate charge of the high-side MOSFET however.

Please let us clarify whether this term could be applied into LM25101 as well or not.

If not, please let us know your actual recommendation on this device instead.

We thank you in advance for your information.

Best regards,

over 12 years ago

0 Ibrahim Kamal over 11 years ago

Intellectual 390 points

same problem here...

Couldn't find any way to estimate or calculate this capacitor value... any clues from TI ?

Thanks!

0 Atsushi Okui over 11 years ago in reply to Ibrahim Kamal

Genius 4015 points

Hello,

I could get some information on this inquiry that the capacitor need to be able to keep enough derating on following condition;

1. applied 10 times of Qg value on external H-side MOSFET

2. applied Vin_max

0 Ibrahim Kamal over 11 years ago in reply to Atsushi Okui

Intellectual 390 points

Thanks a lot, that helps :)

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Inquiry regarding bootstrap capacitor value on LM25101