LM5117: how to choose a inductor value for buck charger of CC/CV

Tong Pan92

Part Number: LM5117

Hello:

Anyone can help me on how to choose a inductor value for charger using buck converter with CC/CV mode? I know for normal buck DCDC converter, the inductor is based on output current ripple/ switching frequency/ input , output ratio (Duty cycle). but for a charger using buck converter, how about during CC mode, the Vout is not fix value? or I can calculate the L base on CV mode input/out ratio and ignore the CC mode condition

Such as if I want to use LM5117 to do a CC/CV mode charger with Vin=65V, Vout=56V (during CV mode) and Iout=2A(during CC mode).

Thanks and Best Regards

Tong

over 6 years ago

0 David Baba over 6 years ago

TI__Mastermind 40040 points

Hello Tong,

I would set the design to the highest power out. Base your inductor value at this operational point. Please see link below of application note which details this.

www.ti.com/.../getliterature.tsp

Hope this helps?

0 Tong Pan92 over 6 years ago in reply to David Baba

Prodigy 80 points

Thanks David, I will study it, may come back to you if I have anything can't understand.

Best regards
Tong

0 David Baba over 6 years ago in reply to Tong Pan92

TI__Mastermind 40040 points

Hello Tong,

Feel free to reopen thread if you have any further questions.

hope this helps?

Power management

Power management forum

LM5117: how to choose a inductor value for buck charger of CC/CV