The UCC3817EVM is used to evaluate the UCC3817, a Power Factor Correction (PFC) pre-regulator which is typically the first stage in a multi-stage power system. The PFC preregulator was designed with a boost power converter topology. The high output voltage of the boost converter generally needs to be stepped down with a forward power converter. The UCC3817 BiCMOS Power Factor Preregulator control IC uses leading edge modulation that, when properly synchronized with the down stream converter's control IC, can significantly reduce the RMS current through the preregulator's boost capacitor.
The UCC3817EVM can also be used to evaluate the UCC3818 BiCMOS Power Factor Preregulator.