Hi
I need to make a power supply with the following parameters:
VIN: 230VAC
VOUT: 12VDC
POUT: ~10W
CLASS: II
OVC IV
NORM: 61010-1
I face the following problem: to achieve this i need a creepage and air distance of 11mm. And there is like no optocoupler on the market for such wide distances. Do I miss something? Or are these flyback power supplies not made for OVC IV?
Thanks for any help
Hello Cedric, welcome to the MPS Forums!
Did a quick search and found that Overvoltage Category IV (OVC IV) is in compliance with IEC61010-1, which I know to be a strict isolation requirement. Not many off the shelf flyback will have integrated optocouplers since they won’t meet that 11mm creepage.
What if you avoided the optocoupler feedback altogether?
Check out these Primary Side Flyback ICs that would fit those VIN, VOUT, and POUT requirements:
Hi Krishan
Thank your for your answer.
I have a further question about this overvoltage / Isolation topic.
With OVC IV I have an isolation distance of 5.5mm between L & N at the input.
Is the High Voltage after the rectifier not a Problem between the Pins of the SOIC-8 Chip? I mean there is only a 2.54mm gap between HV and GND Pin?
Thank you very much for your assistance
Good point on the SOIC-8 package. If a high voltage is present across pins in a single SOIC-8, then I suppose looking at other parts with a higher pin package would perhaps be preferred.
I also thought about the following IC for the application:
MPX2001 | All-in-one Flyback Controller with Integrated Primary and Secondary, Synchronous Rectification Driver with Capacitive Isolation | MPS
This controller can be used for both SSR and PSR applications so an optocoupler can be eliminated from the design. Take a look at the datasheet and see if this is a fit. Hopefully the bigger package is ok with your creepage reqs. The HV pin is also either separated or next to a NC pin, increasing the gap.
