LM5000: Soft start capacitor maximum value

Karl Johnson

Part Number: LM5000

Hello

I see that quite a few people have asked if there is a way to calculate the soft start capacitor on the LM5000 and the answer seems to be "just try different values until you get the right result".

Is there a maximum value that the SS capacitor can be?

Thanks

Karl

over 4 years ago

0 Youhao Xi over 4 years ago

TI__Guru 73150 points

Hi Karl,

Thank you for consider the LM5000. There is no theoretical limit on the soft start capacitor. However, the SS current can be as low as 8uA, so you should choose a capacitor of the leakage less than 8uA, otherwise you would not be able to turn on the circuit. Larger capacitor usually has big leak current.

Thanks,

Youhao Xi, Applications Engineering

0 Karl Johnson over 4 years ago in reply to Youhao Xi

Prodigy 225 points

Thank you for the quick response. We'll try some values in our circuit.

0 Youhao Xi over 4 years ago in reply to Karl Johnson

TI__Guru 73150 points

Thank you Karl for the feedback. Let me close this thread here for now, and you are welcome to contact us if we can be of further assistance.

Good luck in your project.

Thanks,

Youhao

Power management

Power management forum

LM5000: Soft start capacitor maximum value