DER-212 PLC810 Reference Design Will it work on 115 VAC 400 Hz???

The IC assumes a DC input - It assumes that most applications it will be used in will have a PFC front end.
As such the input line frequency is immaterial.
The datasheet can be found at
http://www.powerint.com/sites/default/files/product-docs/hiper_family_datasheet.pdf

Other information can be found at
http://www.powerint.com/en/products/hiper-family/hiperplc

Hi,
The DER-212 application not does not have a PFC in front of the
power supply. The PFC is included in the PLC810 chip. If it was
running off DC obviously the input frequency does not matter. The
PLC810 is looking at the voltage across resistor R6 and R8 and is
monitoring the 400 Hz input current.

Hi,
The DER-212 application not does not have a PFC in front of the
power supply. The PFC is included in the PLC810 chip. If it was
running off DC obviously the input frequency does not matter. The
PLC810 is looking at the voltage across resistor R6 and R8 and is
monitoring the 400 Hz input current.

Your're right. I am confusing this IC with another one which does not have a PFC functionality inside the chip.
fundamentally I think it should not work at 400 Hz but I have not personally tried it to comment on how good or bad the power factor can be expected to be. The output voltage regulation should not be affected by line frequency.