LT8302 Not regulating Secondary correctly at +/-12V

Here is a quick circuit that works fine.

Charly

I noticed the datasheet calls out there might be instability at light load and large primary inductances but there is no information provided to calculate a maximum value. Is the 7491195212 transformer which has 21uH coil inductance to large for the LT8302 at light loads? Would swapping in a LT8302-3 make a difference?

I used the same transformer you have to make the circuit work.

I used the Aux input from the primary side to make the math work.

Try this circuit , it sshould work.

Charly

Any reason this would not work on the PRI pins 1 & 3?

I made the changes to match your circuit. It seems to work fine.

Also we do have a transformer recommnedation for a +-12V output on page 14 of the datasheet.

Charly

Hi Charly, 
Yes the simulation works but on the Hardware the regulated output is not the expected +/-12V. At Min load (15mA) the output is +/-24V. With a 30 ohm load the output is at 14.6V and at a 20 ohm load the output is at 13.3V.  Is this an issue with the large 21uH inductance on the transformer Primary Coil?

Can you pelase send me your schematic and your GERBER files so I can take a look?

Hey, unfortunately I cannot share SCH or Gerber data. We plan on testing the circuit with a lower inductance transformer to see if that makes the difference. 

Did you check out page 14 of the datasheet? It recommends a transformer for your application.