UC1825: UC1825 in CV/CC mode

Hi,

UC1825 for CV mode is straight forward. When you use it for a double-ended forward converter such as push-pull, you obtain CV mode.

For CC mode, this device is not intended so you need to add your external circuit to achieve. 

You need to show what CC mode is your intended with a diagram, for example at what conditions you need to have CV or you need to have CC.

For CC mode, basically you need to add a current sense and control circuit to override the CV feedback so CC control to become dominant. You can have either CV or CC at different time but not at the same time.

Hi,

If you want to use two external op-amp to substitute the internal op-amp of UC1825, it looks you can set up the internal op-amp as a voltage follower by tie its E/A OUT pin to its INV pin, then connect your external op-amp circuit output to UC1825 NI pin.

Hi,

For external op-amp circuit, that should be your choice to make. We do not have an application note. For the internal opamp to connect it to be a voltage follower it should be just like what I described in my last reply. I am not clear what application note you are looking for. There are many op-amp devices can be used for your external circuit.

Hi,

If you are looking for slup349, then you can get it from the below link. If you want to get further detail for the inside that file, please create a new thread with UCC28951 and asking what the further details you would like to have.

Design review of a 2-kW parallelable power supply module (PPT) (ti.com)