Good afternoon,
We recently received a first prototype board with the LM25118. This was based on a TI Webench design for a 10-40V input with a 24V 3A output. The operation I am seeing is that the output of the DC/DC is always a few volts higher than the input.
14 V input --- > 15.9V output
18V input ---> 20.2V output
22V input ---> 24.4 V output
First problem is the output should always be 24 V. The second problem is it never seems to hit the buck stage. Can you help with a quick schematic review? We have had some assembly issues with this company, but 4 boards seem to be behaving similarly. Note, M1 and D1 were swapped from the Webench design due to availability so please pay special attention to those.
Everything downstream seems to be working appropriately and is not pulling excess current. The whole board is only pulling 15 mA at 22 V input
Thanks!
