ZHCSJY8E june 2019 – february 2021 UCC256402 , UCC256403 , UCC256404
PRODUCTION DATA
Before determining the resonant tank component parameters, a nominal switching frequency (resonant frequency) should be selected. In this design, 100 kHz is selected as the resonant frequency.

The resonant tank parameters can be calculated as the following:



After the preliminary parameters are selected, find the closest actual component value that is available, re-check the gain curve with the selected parameters, and then run time domain simulation to verify the circuit operation.
The following resonant tank parameters are:



Based on the final resonant tank parameters, the resonant frequency can be calculated:

Based on the new LLC gain curve, the normalized switching frequency at maximum and minimum gain are given by:


The maximum and minimum switching frequencies are:

