Hello
I want to use the “ucc28810evm-002”to design my project, the project parameters are that :
Input voltage:160V~260V
Output voltage:300V
Output current can be adjusted form 0.1mA to 1A
I want to use UCC28810EVM-001’s control method. By current feedback to maintain the LED drive current to follow my current set point. specifically through adjust UCC28810 pin2(EAOUT).but I note that ucc28810evm-002 is a transition mode buck. the peak current in Q5 is sensed by R35 and R38 and is controlled by the UCC28811 at pin 4 where it is compared to a reference inside the IC. Once the peak current is reached the Q5 turns off. Once the current decays to zero Q5 is turned on. So the current in L3 is a saw tooth with constant amplitude and so constant average.
And I have some question?
How to design the inductors for the buck circuit to meet the requirements (can be adjusted form 0.1mA to 1A)?
How to set the inductor turns for UCC28810 pin5(TZE)
And how to set the UCC28810 pin4(ISENSE)=>(because now use feedback mode instead of the average voltage of the sensing resistor for pin4)
Best regards
Wskvhdl
