Dear TI team，
I used LM5185-Q1 designed a dual output flyback circuit, but work abnormally.
Would you please help check the protential issue?
Detail:
1. the design is referred TI calcuate doc, detail refer to the attachment.
2. schematic is attached.
3. when we got the PCBA, we powered on, and found power supply OC triggered, and the transformer is squealing.
4.we found the primary voltage is uncontroller, and will reach around 60V, and ICs connected with the secondary outputs are damaged.
5.We guess maybe this is caused by the load is too light and no zener diode protection for the outputs.
6. We removed the damaged parts, add 3.5W load (resistors) and TVS (we only have TVS in hand) for outuput, but still can not work.
7. We changed the Rcs from 1.5mohm to 8mohm, it can work. But 8mohm can not meet our max ouput power requirement.
8. We tried to decrease the Rcs to 4mohm, the output voltage still can not work.
Would you please help check the protential causes except dummy loads or zener diode proteciton?
Other questions related to the datasheet:
1. For DCM mode, the FSW is 350kHz, but how can we decide when to turn on/turn off the MOSFET? Duty is decide by the Iout, how can we sense the Iout?
2. For FFW mode, the MOSFET turn off is decided by the voltage on Rcs, if reached 20mV, turn off the MOSFET. but how to decide when to turn on the MOSFET and how to decide the Frequency?
