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DER-657 or DER-733 guide for a design of the 60W PFC 3in1 dimmable LED driver ?

Posted by: brodo on Wed, 06/10/2020

I am about to design a 60W PFC 3in1-dimmable LED driver with synchro rectification because of low, 12V output.
I see 2 ways to do it: DER-657 or DER-733 guides. The latter one is equipped with separate PFC front-end.
Will the simpler PFC of the DER-657 guide fulfill the typical requirements for a industrial LED driver ?
The part reduction is significant in that case.


Submitted by PI-Zek on Thu, 06/18/2020

The Switched Valley Fill SVF PFC design like DER-657 can also fulfill the typical requirements for an industrial LED driver. The advantage is like you mentioned lower component count for a power supply.

The advantage of a 2-stage flyback LED driver with PFC at front-end like DER-733 is its lower THD (input current total harmonics) especially at low-line and higher power factor (PF) with additional boost stage.

If you will operate at low-line only designs (90VAC-132VAC), OR high-line only designs (185VAC-277VAC), with low THD and high PF requirements, the flyback LED driver with SVF PFC (e.g. DER-657) is best for lower component count thus lower cost LED driver applications.

If the design requires universal input line with both low THD and high Power Factor requirements at all input line, the 2-stage design like DER-733 is the best design example for your application.