TOP264 surge immunity
Hi,
i have a question regarding surge immunity of power supply based on TOP264 - the power supply survive 4kV surge test, but it restarts, even with pin 1 "V" (UV/OV protection input) connected to ground. Increasing the bulk capacitor value doesn't help significantly. So there is probably another way which disturbance affects the TOP264 control loop. Can You provide a tip where we should look for, how to make TOP264 design immune to such surge disturbance?
Comments
Hi,
thank You for advice, now the issue seems to be solved.
Another question - could You share a guideline/tips, how to choose/tune value of RCDZ snubber components please?
Best Regards
Michal
Hi Michal,
The PIexpert tool gives starting values for snubber components. You can refer to attached documents for some basic formulas for flyback converter snubber design.
| Attachment | Size |
|---|---|
| flyback snubber design (2.08 KB) | 2.08 KB |
Hi,
What are the DM and CM surge specs. The layout plays key in role in passing the surge specifications. Did you measure output voltage & bus voltage to verify the root cause for auto-restart?
Please check application note AN-47 for layout guidelines as given below.
https://ac-dc.power.com/sites/default/files/product-docs/an47.pdf
If issue, not resolved, please share the schematic and layout files.