MT40A4G4NRE-075E Datasheet, PDF (14/21 Pages) Micron Technology – TwinDie 1.2V DDR4 SDRAM

16Gb: x4, x8 TwinDie DDR4 SDRAM
Electrical Characteristics – AC and DC Output Measurement
Levels
Figure 7: Differential Output Slew Rate Definition
TR_diff
V_OH,diff(AC)
V_OL,diff(AC)
TF_diff
Table 12: Differential Output Slew Rate
For R_ON = R_ZQ/7
Parameter
Symbol
DDR4-1333 / 1866 / 2133 / 2400 / 2666
Min
Max
Differential output slew rate
SRQ_diff
4
14
Note: 1. SR = slew rate; Q = query output; diff = differential signals.
Unit
V/ns
Reference Load for AC Timing and Output Slew Rate
The effective reference load of 50Ω to V_TT = V_DDQ and driver impedance of R_ZQ/7 for
each output was used in defining the relevant AC timing parameters of the device as
well as output slew rate measurements.
R_ON nominal of DQ, DQS_t and DQS_c drivers uses 34 ohms to specify the relevant AC
timing paraeter values of the device. The maximum DC high level of output signal = 1.0
× V_DDQ, the minimum DC low level of output signal = { 34 /( 34 + 50 ) } × V_DDQ = 0.4 ×
V_DDQ
The nominal reference level of an output signal can be approximated by the following:
The center of maximum DC high and minimum DC low = { ( 1 + 0.4 ) / 2 } × V_DDQ = 0.7 ×
V_DDQ. The actual reference level of output signal might vary with driver R_ON and refer-
ence load tolerances. Thus, the actual reference level or midpoint of an output signal is
at the widest part of the output signal’s eye.
PDF: 09005aef85fd40a1
DDR4_16Gb_x4_x8_2CS_TwinDie.pdf - Rev. D 12/16 EN
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