UCC12050: Input Capacitor

Hirotsugu Kobayashi

Mastermind 9530 points

Part Number: UCC12050
Other Parts Discussed in Thread: UCC12040,

Hi, team.

In the ISOW78 series, 100uF or more is recommended for the input capacitor.

Is it not necessary for the UCC12050 and UCC12040?

Best Regards,

over 5 years ago

0 Peter Meaney over 5 years ago

TI__Mastermind 31580 points

Hi Hirotsugu-san,

I checked the UCC12050 EVM , and it uses a 10uF and 0,1uF ceramic parts as the input filter. The switching frequency is much higher with UCC devices so less input filtering is required.

Regards

Peter

0 Hirotsugu Kobayashi over 5 years ago in reply to Peter Meaney

Mastermind 9530 points

Hi, Peter,

The ISOW78 series does not have 100uF in EVM.
The 100uF input capacitor was added in a revised data sheet.
I understand that this is to prevent output overvoltage when the input voltage drops.

Do UCC12050 and UCC12040 have the same problem?
Is the internal topology different?

Best Regards,

0 Zhemin Zhang over 5 years ago in reply to Hirotsugu Kobayashi

TI__Prodigy 130 points

Hi Hirotsugu-san,

UCC12050/40 and ISOW78xx are different designs. We don't see the overvoltage on UCC12050/40 when input voltage drops.

So UCC12050/40 is not necessary to have 100uF for the input decoupling capacitor.

Let us know if you have further questions.

Best regards,

Jimmy

Power management

Power management forum

UCC12050: Input Capacitor