opampsmoker
Member
Hi,
Why do all the datasheet and app note schematics of high power offline flybacks with FSCQ1565 cotroller show no primary clamp whatsoever?
They only show a small Drain source capacitor, which they call the "resonant capacitor".
(which is true but it hardly seems big enough to quench leakage spiking for cases of overload, etc)
The internal FET is only 650V rated. This is surely gross designer irresponsibility?
FSCQ1565 datasheet (pg 19 schem)
https://www.onsemi.com/pub/Collateral/FSCQ1565RT-D.pdf
App note for FSCQ1565 (AN4146) (pg 19 schem)
https://www.onsemi.com/pub/Collateral/AN-4146.pdf.pdf
Why do all the datasheet and app note schematics of high power offline flybacks with FSCQ1565 cotroller show no primary clamp whatsoever?
They only show a small Drain source capacitor, which they call the "resonant capacitor".
(which is true but it hardly seems big enough to quench leakage spiking for cases of overload, etc)
The internal FET is only 650V rated. This is surely gross designer irresponsibility?
FSCQ1565 datasheet (pg 19 schem)
https://www.onsemi.com/pub/Collateral/FSCQ1565RT-D.pdf
App note for FSCQ1565 (AN4146) (pg 19 schem)
https://www.onsemi.com/pub/Collateral/AN-4146.pdf.pdf