SPRACU1A October 2020 – June 2021 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6441 , AM6442
As with VREFCA, the nominal value of the VTT supply is 50% of the DDR4 supply voltage. Unlike VREFCA, the VTT supply is expected to source and sink current; specifically the termination current for the ADDR_CTRL net class Thevenin terminators. VTT is needed at the end of the address and control bus and it should be routed as a power sub-plane. VTT must be bypassed near the terminator resistors.