LYT1604 20 W led driver design
I am designing a 20W LED driver based on lyt1604 and following AN-67. I constructed the AC-DC and DC-DC side separately on a DOT board.
I did this for both hide side and low side topologies.
DC - Dc side was tested with 60V Dc power supply and worked well.
But when DC -DC side is connected with AC-DC side , the IC ( lyt1604 ) is burnt. This happed for both topologies.
What can be the reasons ? Any precaution to make ?
Thanks
Upeka Botheju
Comments
The recommended layout (including Dbuck positioning) is described in detail in AN-67.
Here is my suggestion for positioning components on the AC-DC portion of your board. If you prefer through-hole components, you can substitute a UF4005 for the US1J, since both parts have a specified trr of 75 ns. It is vitally important that C2 D1, L2, and C3 be located on the AC-DC portion of your setup., since a tight loop area is demanded for the output section of the LED supply.
| Attachment | Size |
|---|---|
| AN67_layout.pdf | 74.34 KB |
The catch diode (Dbuck in the sample schematics) should have a tight return path, (very close to the LYTSwitch "D" pin, and with a short return path to Cfilter2, which means it should be located on the portion of the prototype that has the LYTSwitch. This may be a cause for your blow-up problem.