Please do some tests on Hiper-LCS2 for us?

Posted by: treez on 10/19/2025

Hi,

Please do the following soak tests on Hiper-LCS2 so we can see how it performs?

Do repeated short circuit output test, over and over again.

Do start-up into short circuit, over and over again.

Do start-up into 200mF of output capacitance, over and over again. (48V output and max load aswell)

_____ ___ ____

Also, please explain if HiperLCS2 can be used with a ti.com dual interleaved BCM PFC stage preceeding it?

Comments

Hi treez,

Good day and thank you for posting in our forum. The response should auto restart on your mentioned conditions. The device has a short-circuit protection and will trigger short fault auto restart.

We do not recommend having too high value of output capacitor. This will cause a non-monotonic rise and can cause faults, especially it will require high primary current during start up.

We recommend powering up a board from our list of example designs for your project and confirm performance.

Regards, Gavin

Thanks, what is the maximum output capacitance that could be used with Hiper-LCS2 and say a 48V output?

Surely if starting up into a very high output capacitance aswell as full load then it would just keep increasing and reducing its frequency until it was finally at the regulation voltage.?

Our customers may put what they like on the bus, and it may have big input capcaitance, so please advise us as we need to know what exactly will happen?...would it blow up or just shut down, or just take a long time to get into regulation?

As you know, a hard switching Full Bridge SMPS, or a PS Full Bridge can start up into full load and any amount of output capacitance.

Short cct output is a known LLC failure mode.....is there no chance of doing the repeated short cct test?...And publishing the results?.

Hi,

Putting too much output capacitance can trigger Output UV Fault as it tries to charge the output capacitors. Output UV Fault become active after start-up and hand over to secondary mode. Fault is activated if FB pin remains below VFBBSTN(TH) for 64 ms. PSU will turn off or go to auto restart during this condition.

We will share your feedback regarding output short to be included in our published Design Example Reports. But the protection should be activated if a short is detected.

Regards, Gavin