UCC28070: How to mange RSYNTH pin function

ROBERTO VOLPINI

Part Number: UCC28070

Hello,

I'm going to design a 2kW wide range PFC using UCC28070 controller, this is my first time with this controller, would you be so kind to explain the reason why the Current Synthesizer Block nedd to be disabled? is not the one responsible for the formation of the current envelope, if yes, why disable it?

Moreover do you have some explanation why use TA instead of shunt resistor (of course with OpAmp due to high signal level reuired)

Thank you

Roberto

over 5 years ago

0 Peter Meaney over 5 years ago

TI__Mastermind 31580 points

Hi Roberto,

Can you tell me where did you read the advice to disable the Current Synthesizer Block? There is an design guide in the datasheet and a calculator tool on the UCC28070 webpage.

There is also a 1.2kW reference design with conrtol board and main board PCB and schematic on the webpage.

The use of the current transformer reduces the power dissipation in the current sense circuit which is attractive at higher power levels like 2kW.

It is possible to use current sense resistors with external high speed op-amp amplifiers but the PCB layout needs to be good and we have found that there can be cross-coupling if customers try to use dual op-amp packages.

Regards

Peter

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

TI__Mastermind 31580 points

Hi Roberto,

Since there has been no more questions to my response I am going to close this post.

Please open a new post if you have more questions.

Regards

Peter

0 ROBERTO VOLPINI over 5 years ago in reply to Peter Meaney

Prodigy 130 points

Thanks, now I'm going to make a Spice simulation of the circuitery, then I'll be in condition to better understand the functions of this controller

BR/Roberto

Power management

Power management forum

UCC28070: How to mange RSYNTH pin function