Which one to Choose out of UC3525 or UC3825 for dc dc

[bdmehta]

Dear Members,

I am using 3525 PWM IC for DC DC Converter in forward topology for low to medium power buck, I am thinking to switch over to UC3825, current mode converter PWM IC.

Does it worth to switch over to UC3825? Is there any specific advantages? I have tried but face lot of problems in realising the DC DC COnverter.

Can anyone help me and give in-depth suggessions on my applications?

Regards,

Bharatkumar.

 

[dick_freebird]

Current mode control primarily lets you make a faster
responding (to load step especially) converter. You also
gain some degree of short circuit protection (presuming
you size / rate the power train components appropriately
to the limit-point).

 

[vv_design]

Basically the design of the outer voltage loop should be easier when using CMC (current mode control).

The other big advantage of CMC over VMC (voltage mode control) is that CMC yields to a much lower audiosusceptibility (i.e. stiffness under input voltage perturbations).

As appointed before, you can also get a low output impedance. But you should take into account that using a buck-derived topology, you can get very similar performance in terms of output impedance by means of voltage mode control with type III compensator.