LM5036: dead-time of LM5036

Hello Xiaoying,

I would recommend the UCC25800 as an alternative to the LM5036. It is a new half-bridge transformer driver that includes automatic dead-time adjustment. The typical adaptive dead-time is only 20ns with a max of 45ns. 

Regards,

Jonathan Wong

Xiaoying,

For low power bias, I like Jonathan's recommendation of UCC25800. This IC is low power and has integrated MOSFETs which limit the power to less than 9W typical. The UCC25800 programmable dead time is setting the dead time between the two integrated primary side half-bridge MOSFETs but the LM5036 dead time you are asking about is setting the dread time between the primary MOSFET and secondary SR. Most half-bridge controllers with integrated SR gate drive will have a fixed amount of primary-to-secondary minimum dead time on the order of what you are seeing with LM5036. One option for decreasing the dead time is to use an external SR controller or gate driver that is either self-driven or control-driven but you would give up many LM5036 features such as pre-bias start and guaranteed minimum dead time (risk of cross-conduction). You can see slightly less dead time settings with UCC28951 but this is a PSFB controller. I think if you need to stick with LM5036, what you see is what you get.

Regards,

Steve M