SPWM Filter position

[Egg]

Hello, i am trying to build an inverter using the egs002 spwm driver but i am quite confused with the filtering of the spwm signal.
According to the schematics, the transformer seems like it is driven without filtering the spwm signal theres a filter capacitor only after its stepped up. I might be missing something here but my understanding was that iron core transformers are best driven with the low frequency sine wave and not unfiltered spwm. Can someone explain to me why it is designed that way?

[davekni]

I'd guess that leakage inductance of transformer T1 provides the needed series inductance.  However, I'm not familiar with this specific driver nor transformer.