Hi Support,
Customer is using TI TPS40211EVM Eval Board to modify to their specification.
1) Output Constant Current at 300mA and DC55V max,
2) Dimming capability with Direct PWM DC24V input without additional PWM signal.
Can I take this offline as there are confidential schematics to share?
However the ringing problem is quite serious.
The output current (Iout 1 and Iout 2 measured voltage across RL1 (0.47ohm) and RL2 (0.47ohm) at LED module ) are ringing at 100MHz,
Signal of Vf of D1 and Vds of Q1 are probe.
Vf of D1 ring at 119Mhz when Q1 turn on
Vds Q1 ring at 5MHz during off and 19MHz during on
The leakage magnetic is detected using pickup coil (basically a ferite rod wound with wire).
This product will be tested under UL and FCC for US market. therefore I worry the FCC will not pass with the high emission that I believed was caused by the ringing problem.
Please suggest me a potential solution.
Thanks.
