LNK 306 strange behavior

Posted by: sabouras on 11/21/2013

I made the circuit of LNK306 as it looks in datasheet.

I use 3.6uF/400volt instead of 4.7uF/400volt. The problem is that the output voltage oscillaytes form 5 volt to 17volt.

Could you please advice what i must check or change?

I use all componets as show to datasheet.

Thanks for any ideas.

Comments

Hi,

What is the output load when you tested the power supply?

What is the output inductor you used? You could measure the inductor current to check if the inductor went to saturation or not, it will depend on the load condition.

Thanks

i measure it in air (without any load) , with 1K resistor as load and 100R resistor load.

The output coil is from wruth electronics 1uH with saturation current of 400mA.

In none case i could draw that amound of current

Hi,

To understand what really happened, would you please record the waveforms on BP to S, FB to S, D to S and S to output ground?

Thanks