Other Parts Discussed in Thread: LM65680, LM76003
Tool/software:
Hello everyone and TI teams.
I am currently designing my board's power stage which would ideally allow to convert one 36Vdc line in two separate lines:
- A 24Vdc power supply for the motors and drivers
- A 3.3Vdc line to power all my control and logic ICs (mcu, transceivers etc.).
I was considering using the LM65680 to achieve the 36Vdc to 24Vdc conversion, and using an LM76003 to achieve the drop to 3.3Vdc.
As I want to meet the IEC-61325 standard, which associated EMI standard is CISPR11, I am willing to optimize my board's design to reduce a maximum the risks of EMI event I could have to face.
Knowing that I which of the following configurations do you think would fit my need the best:
- Connecting my two converters in parallel from the same +36Vdc line, using the same switching frequency and synchronizing the to facilitate EMI filtering on the 36Vdc line before both of them. Which from what I understood would also isolate my logic supply from the perturbation induced while driving the motors (feel free to tell me if I am wrong, I'm willing to learn).
Or:
- Connect firstly the LM65680 to the 36Vdc line and drop to 24Vdc line that will supply my motors and drivers, and connect my LM76003 to this same 24Vdc line to achive the drop to 3.3Vdc to allow local filtering for this specific derivation?
Thank you in advance for your time and advices.
PS: I will also consider any alternative design idea if you think it is more optimized.
