TPS55340: When FB connect to GND, why COMP is a constant source current

Lin_Charles

Part Number: TPS55340

Hi team,

I have read below application note and find that when the FB pin of the TPS55340 is grounded, the COMP pin will be a constant current source of 42 µA? Please help share me what is the reason? Thanks.

http://www.ti.com/lit/an/slva559/slva559.pdf

over 4 years ago

0 Jasper Li over 4 years ago

TI__Mastermind 46905 points

Hi Charles,

the FB is connected to the negative input of the error amplifier. the positive input of the error amplifier is reference voltage. thus the error amplifier outputs the maximum current, which is 42uA

0 Jack Gratteau over 4 years ago in reply to Jasper Li

Prodigy 25 points

Hi Jasper - not certain why I'm now being copied on your other traffic - this is my home account and I hadn't contacted you from this - please check your side and see how it has jackgrat2005 in the queue - Thanks, Jack

0 Jasper Li over 4 years ago in reply to Jack Gratteau

TI__Mastermind 46905 points

Hi Jack,

I'm not sure about your meaning. please send me a private message if it is not about technical question related to the post.

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TPS55340: When FB connect to GND, why COMP is a constant source current