Need Quasi resonant Flyback controller with Max frequency setting?

[Faringdon]

Hi,
We need to do an Offline 90-265VAC flyback , but the  customer needs us to use a certain transformer, which they already bought in high volume...therefore, we need a QR Flyback controller with a maximum frequency setting, so that the switching frequency doesnt go too high when the mains is high.
We can only find the NCP1340, and digikey wont let you search on this parameter, does anyone know any others?

[jpanhalt]

I seem to have found it on DigiKey by entering the number in the search box.

https://www.digikey.com/en/products/detail/onsemi/ncp1340a6dr2g/8258551

There are several version available.  The datasheet, as expected, shows the other versions.

EDIT: I misunderstood to what "this" referred.

[Faringdon]

Thanks, yes, the NCP1340 is the one i found.....but there are no others in that family which have max freq set......and where it is settable, the tolerance is badly huge.......any ideas for one with a low max freq set, and well toleranced.
L6566 has QR operation with a settable max frequency, but its a 16 pin chip and we dont have room.

Then theres the iW1820, QR with max freq = 72khz...very nice...but no direct output regulation

[jpanhalt]

That family does have a maximum frequency clap set by a resistor as does the NCP1342.

You say the band width is too great (see attachment).  What band width is acceptable?

[Faringdon]

Thanks, the NCP1340B4 FMAX pin bias current is 9 to 11uA.
Also, the V(FMAX) must stay below 4V......so keep it below 3.9V for some margin...
So then you use a 330K-22K series combo...giving FMAX = 67kHz to 82kHz.

...bit wider than would like...but maybe we just have to make do, would prefer +/- 5kHz

NCP1340
https://www.onsemi.com/products/power-management/ac-dc-power-conversion/offline-controllers/ncp1340