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Unbuffered DIMM
datasheet
Rev. 1.0
DDR3L SDRAM
11.2 VREF Tolerances
The
VREF(DC) is the linear average of VREF(t) over a very long period of time (e.g. 1 sec). This average has to meet the min/max requirements of VREF. Fur- thermore VREF(t) may temporarily deviate from VREF(DC) by no more than ± 1% VDD.
voltage |
VDD |
VSS |
time |
Figure 2. Illustration of VREF(DC) tolerance and VREF ac-noise limits
The voltage levels for setup and hold time measurements VIH(AC), VIH(DC), VIL(AC) and VIL(DC) are dependent on VREF.
"VREF" shall be understood as VREF(DC), as defined in Figure 2.
This clarifies, that
This also clarifies that the DRAM setup/hold specification and derating values need to include time and voltage associated with VREF
Timing and voltage effects due to
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