Dear engineers,
I would appreciate your insights regarding a behavior I observed on the LTM4613 module.
Purpose of the question:
To confirm whether the VIN and VD pins of the LTM4613 are DC-conductive internally.
Background:
During a leak check on our board, VIN and VD appeared to be shorted from a DC perspective. No external short was found on the PCB, so I began investigating whether this conduction occurs inside the module.
My understanding / hypothesis:
According to Figure 1. Simplified Block Diagram in the datasheet, the INPUT FILTER section seems to include a high-frequency inductor element between VIN and VD.
Together with the external input capacitors connected to VIN and VD, this forms what is effectively a pi-type filter.
Based on this structure, it is reasonable to assume that VIN and VD are DC-conductive (i.e., no galvanic isolation exists), and that only high-frequency noise is attenuated by the internal inductor.
Question:
Could you confirm whether this interpretation is correct? Specifically:
Are VIN and VD internally connected with DC continuity inside the LTM4613?
Is the conductive path created by the inductor element in the INPUT FILTER block shown in the datasheet?
Is it correct to understand that the external capacitors with this internal inductor form a pi-filter, resulting in the observed DC short?
Any technical clarification or additional insight would be greatly appreciated.
Best regards,
Tsukada
