MP2940 VID pins PU to 1.05V instead of 1.8V

DC-DC Power Converters
1

Hi MPS Team,

I’m designed a motherboard that has Intel Tiger Lake UP3 Processor.
the design uses two MP2940 controllers, one for VCCIN (CPU Power Rail), and one for VCCIN_AUX (PCH Power rail)

I mistakenly connected the VID pins for VCCIN_ AUX controller to 1.05V (VCCST_CPU) although Intel recommends 1.8V or 3.3V:

V1P8A
V1P8A1015×958 129 KB

the design has already sent to factory and we need to do a revision in order to make any change.
we need a temporary answer/solution for the bring up phase.

Intel connected VCCIN controller SVID pins to 1.05, and that what created the confusion, since we have implemented a VCCIN_AUX design same as VCCIN design in terms of VID\SVID PU power rail.

what do you suggest to solve this issue? and will the design work just by connected to 1.05 as stated in your datasheet?

2

Hello. Thanks for reaching out to MPS.

For your question, since this is directly related to an Intel Ref Design, would first need to contact Intel ref design team on latest updates and implementations as they will have most up-to-date information on utilization of MPS power supply in their design and guidelines on how they should be connected. Thanks.

Regards,
Christian