UC2875: Current Mode with Slope Compensation

6589738

Part Number: UC2875
Other Parts Discussed in Thread: UCC28951, UCC28950

Hello,

I would like to use the UC2875 in Current Mode with Slope Compensation?
I found in the component datasheet how to use it in voltage mode, and how to use it in current mode: "For current-mode control the ramp generator may be disabled by grounding the slope pin and using the ramp pin as a direct current sense input to the PWM comparator".
My goal is to use the UC2875 in current mode with slope compensation.

So I have to put the current sensor output information directly in RAMP pin. And for the slope compensation, I think I have to add a resistor (Rslope) connected to VCC?
Is it possible to have an application schematic to help me for my design?

Thanks in advance,

Benoit,

over 4 years ago

0 Blake Soileau over 4 years ago

TI__Intellectual 1200 points

Benoit,

We are looking into this case. Please allow 24-48 business hours before a response.

0 Mike O' over 4 years ago in reply to Blake Soileau

TI__Guru* 86266 points

Hello,

If this is a new design I would consider using the UCC28950 or UCC28951 phase shifted full bridge controller. These are designed to operate in peak current mode control and has internal slope compensation.

The other reason to use the UCC28950 or UCC28951 they are 3rd and 4th generation of the Unitrode/TI PSFB controllers. These devices are easier to design with and use. The following link will bring you to an application note that describe how to design with these devices. https://www.ti.com/lit/pdf/slua560

Regards,

Power management

Power management forum

UC2875: Current Mode with Slope Compensation