MT40A256M16GE-075EAIT Datasheet, PDF (290/359 Pages) Micron Technology – Automotive DDR4 SDRAM

4Gb: x8, x16 Automotive DDR4 SDRAM
Electrical Characteristics – AC and DC Output Driver Charac-
teristics
5_213'B&7 
9₂₈₇
,₂₈₇
Table 121: Output Driver Electrical Characteristics During Connectivity Test Mode
Assumes R_ZQ Ω; ZQ calibration not required
R_{ON,nom_CT}
Resistor
V_OUT
V_OB(DC) = 0.2 × V_DDQ
R_{ONPD_CT}
V_OL(DC) = 0.5 × V_DDQ
V_OM(DC) = 0.8 × V_DDQ
Ω
V_OH(DC) = 1.1 × V_DDQ
V_OB(DC) = 0.2 × V_DDQ
R_{ONPU_CT}
V_OL(DC) = 0.5 × V_DDQ
V_OM(DC) = 0.8 × V_DDQ
V_OH(DC) = 1.1 × V_DDQ
Min
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Nom
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Max
1.9
2.0
2.2
2.5
1.9
2.0
2.2
2.5
Unit
R_ZQ/7
R_ZQ/7
R_ZQ/7
R_ZQ/7
R_ZQ/7
R_ZQ/7
R_ZQ/7
R_ZQ/7
Output Driver Electrical Characteristics
The DDR4 driver supports two R_ON values. These R_ON values are referred to as strong
mode (low R_ON: 34ȍ) and weak mode (high R_ON: 48ȍ). A functional representation of
the output buffer is shown in the figure below.
Figure 231: Output Driver: Definition of Voltages and Currents
Chip in drive mode
Output driver
V_DDQ
To
other
circuitry
like
RCV,
...
I_PU
R_ONPU
R_ONPD
I_PD
DQ
I_OUT
V_OUT
V_SSQ
The output driver impedance, R_ON, is determined by the value of the external reference
resistor R_ZQ as follows: R_ON(34) = R_ZQ/7, or R_ON(48) = R_ZQ/5. This provides either a nomi-
nal 34.3ȍ ±10% or 48ȍ ±10% with nominal R_ZQ = 240ȍ.
The individual pull-up and pull-down resistors (R_ONPu and R_ONPd) are defined as fol-
lows:
CCMTD-1725822587-10418
4gb_auto_ddr4_sdram_z90b.pdf - Rev. D 01/17 EN
290
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