AS4C256M16D3
Reference Load for AC Timing and Output Slew Rate
The following figure represents the effective reference load of 25 ohms used in defining the relevant AC timing
parameters of the device as well as output slew rate measurements.
It is not intended as a precise representation of any particular system environment or a depiction of the actual load
presented by a production tester. System designers should use IBIS or other simulation tools to correlate the timing
reference load to a system environment. Manufacturers correlate to their production test conditions, generally one or
more coaxial transmission lines terminated at the tester electronics.
Figure 24. Reference Load for AC Timing and Output Slew Rate
VDDQ
DUT
DQ
25 Ohm
CK, CK#
DQS
VTT = VDDQ/2
DQS#
Table 37. AC Overshoot/Undershoot Specification for Address and Control Pins
Parameter
-12 BCN/BIN Unit
Maximum peak amplitude allowed for overshoot area.
Maximum peak amplitude allowed for undershoot area.
Maximum overshoot area above VDD
0.4
0.4
V
V
0.33
0.33
V-ns
V-ns
Maximum undershoot area below VSS
Table 38. AC Overshoot/Undershoot Specification for Clock, Data, Strobe and Mask
Parameter
-12 BCN/BIN Unit
Maximum peak amplitude allowed for overshoot area.
Maximum peak amplitude allowed for undershoot area.
Maximum overshoot area above VDD
0.4
V
0.4
0.13
0.13
V
V-ns
V-ns
Maximum undershoot area below VSS
Confidential
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Rev. 3.0
Aug. /2014
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
