ZHCSE24B April 2015 – April 2019 AM3358-EP
PRODUCTION DATA.
Like DDR_VREF, the nominal value of the VTT supply is half the DDR3 supply voltage. Unlike DDR_VREF, VTT is expected to source and sink current, specifically the termination current for the ADDR_CTRL net class Thevinen terminators. VTT is needed at the end of the address bus and it should be routed as a power sub-plane. VTT should be bypassed near the terminator resistors.