0
\$\begingroup\$

I'm using MP2940 IMVP9 Controller for VCCIN (CPU Power Rail) and VCCIN_AUX (PCH Power Rail) for a motherboard that includes Intel Tiger Lake UP3 Processor.

VCCIN Controller uses SVID protocol and VCCIN_AUX uses PVID protocol.

here is the schematic for the design.

from Intel Datasheet we can see that they see that VID pins must be 1.8V/3.3V tolerant: enter image description here

On Intel Customer Validation Platform, they connected VCCIN SVID pins to VCCST_CPU (1.05V) and VCCIN_AUX VID pins to 1.8VA.

On the other hand, In my design, I connected both SVID and VID to VCCST_CPU (1.05V), I made the design according to MP2940 Datasheet: enter image description here

I was confused between SVID and VID at the beginning. and I found out later that they don't have info in MP2940 for the VID PU resistors (or what they call PVID). I guess the following picture was misleading also, because it implies that if someone wants to use VID0,1 they can also connect to VTT = 1.05V:

enter image description here

the following snapshot shows how instead of connecting the pull ups of CORE_VID0 and CORE_VID1 to V1.8A/V3.3, I connected to to 1.05V (VCCST_CPU):

enter image description here

NOTE: I need to change R239 and R238 to 100K PU's.

I need to do a bring up for the motherboard I designed and the PCB's have been already ordered. I surely need to make a revision to fix this. but what could be the easiest solution to connect these pins to 3.3V?

can I connect the rail directly to 1.8A voltage without resistors?

or the only solution is to remove R238, R239, connect to one via of the R238 and R239 pads to a floating 100K resistor and connect the second pin to 1.8V that other PU resistor is connected to. what are the chances that the design would work even if VCCIN_AUX controller VID pins were pulled up to 1.05V?

\$\endgroup\$

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.