UCC28951: current mode circuit

Yuto Kitamura

Expert 6995 points

Part Number: UCC28951
Other Parts Discussed in Thread: TINA-TI, UCC28950

Hi team,

I have a question about UCC28951 with current mode.

I am trying to use this for phase shift bridge converter.

And simulate with TINA-TI.

There is a example file in TINA-TI named UCC28950_AVG and it says it is current mode.

But the circuit seems to be like Voltage mode.

Do you have an current mode example circuit?

or do you have TINA-TI example for current mode?

If I am wrong that this circuit is current mode, please tell me how to simulate it.

best regards,

over 4 years ago

0 Mike O' over 4 years ago

TI__Guru* 86286 points

Hello,

Rsum is tied to ground in the model. This would indicate the model is setup to operate in peak current mode control.

Look up Rsum in the data sheet and there is an equation showing how to calculate the slope compensation and setup.

The following link will bring you to an application note that describes how to design with the UCC28950. The UCC28951 parametrically is almost identical, except the UCC28951 can get slightly more duty cycle. You may find using this application note useful in setting up and adjusting the model for your application.

https://www.ti.com/lit/an/slua560c/slua560c.pdf

Regards,