Tool/software:
Dear TI Team,
We wanted to go with UCC256601 for our 700W CVCC requirement and started going through the datasheet, design calc and reference board documents and we have few doubts. Requesting you to please help.
1. Is it possible to do open loop test by inserting a potentiometer anywhere to check whether the power circuit and calculated values of tank circuit is OK. If yes, please let us know the procedure and precautions to be taken before powering up the board.
2. Gone through all literature and related threads on E2E forum but not sure how to chose Tset value. Do we need to select based on calculated minimum switching frequency. Found in a thread saying that if Fsw_min is 70KHZ, then we need to go with the option for lower frequency. For this value option 3 or 2 or1.
Found in another thread saying that it should be selected based on OCP limit whether it is 3.5 or 4V. To my understand, we can tune Differentiator (Cupper and Rlower) values to match OCP limit irrespective of TSet option. Please clarify.
Please let us know how Tset value is related with Volp.
3. What happens if we chose Tset values with higher frequency for example Option 12 or 24. Does the circuit will work as normal current mode controller without IPPC as mentioned in the datasheet. If yes, what will be the challenges we need to face.
4. Soft start duration is mentioned as 25msec. Please let us know what can we do If we want to increase the soft start duration.
5.We want to go with this design without external aux power either for primary or secondary control circuit. So we will have Aux power from main LLC transformer only. Please let us know the challenges we need to face.
