TPS568215: About input capacitor

Yuto Sakai

Part Number: TPS568215

Hi,

Why is the recommended value of input capacitor more than 40μF in datasheet P.21?

And what percentage of ripple to input voltage is recommended?

Could you please let us know these information because our customer want to use the input capacitor which is lower than 40 μF?

Best Regards,

Yuto Sakai

over 8 years ago

0 Yuchang Zhang over 8 years ago

TI__Mastermind 18510 points

Hi Yuto-san,

I think the 40uF is reference just for typical design, 12Vin/1.2V@8A/400Khz/50mVinripple.

Actually, there is no Vin ripple spec., but as we know it should be the smaller, the better. As experience better the max value don't over 5%

40uF is not a must, smaller and bigger are all possible, depends on your real desgin.

Regards,

Yuchang

0 Yuto Sakai over 8 years ago in reply to Yuchang Zhang

Mastermind 6100 points

Hi Yuchang-san,

Thank you for your reply.
Switching freaquency of typical Application in datasheet P.19 is 1.2MHz.
Could you please let me know where the typical design is written ,12Vin/1.2V@8A/400Khz/50mVinripple.

Best regards,

Yuto Sakai

0 Yuchang Zhang over 8 years ago in reply to Yuto Sakai

TI__Mastermind 18510 points

Hi Yuto-san,

In fact, there is no this description in DS, I checked lots of data but just found this appliction can meet the 40uF data. if this make you confuse, just forget it please.
Whatever, I suggest you just can ignore the 40uF data, and select the input cap samller or bigger, based on your real design.

Regards,
Yuchang

0 Yuto Sakai over 8 years ago in reply to Yuchang Zhang

Mastermind 6100 points

Hi Yuchang-san,

Thank you for your kind support.
I will tell our customer the information.

Best Regards,
Yuto Sakai

Power management

Power management forum

TPS568215: About input capacitor