STM's SG2525A PWM...NOR logic?

[space]

I'm planning on building switch mode power supply described at esp:
http://sound.westhost.com/project89.htm

My local supplier don't have the SG3525 but the SG2525. Looking at the datasheet for those PWM's, I can't make out whether or not the SG2525 can replace the SG3525. From page 1 in the datasheet quote: "the SG3525's output stage features NOR logic". What the SG2525 has it doesn't say. On page 2 there is a block diagram that shows NOR output logic for SG1525 and OR logic for SG1527.

From this I'm guessing the SGxx25's has NOR, and the SGxx17 has OR.

Anyone that DO know what kind of logic the output on the SG2525 has?
If it has a NOR logic, do anyone see any problems in exchanging the SG3525 for the SG2525 in the above mentioned eps-project?

- space -