P4C1026
TIMING WAVEFORM OF WRITE CYCLE NO. 2 (CE CONTROLLED)
(10)
CE
AC TEST CONDITIONS
Input Pulse Levels
Input Rise and Fall Times
Input Timing Reference Level
Output Timing Reference Level
Output Load
GND to 3.0V
3ns
1.5V
1.5V
See Figures 1 and 2
TRUTH TABLE
Mode
Standby
D
OUT
Disabled
Read
Write
CE
H
L
L
L
OE
X
H
L
X
WE
X
H
H
L
I/O
High Z
High Z
D
OUT
High Z
Power
Standby
Active
Active
Active
Figure 1. Output Load
* including scope and test fixture.
Note:
Because of the ultra-high speed of the P4C1258, care must be taken
when testing this device; an inadequate setup can cause a normal
functioning part to be rejected as faulty. Long high-inductance leads
that cause supply bounce must be avoided by bringing the V
CC
and
ground planes directly up to the contactor fingers. A 0.01 µF high
Figure 2. Thevenin Equivalent
frequency capacitor is also required between V
CC
and ground. To avoid
signal reflections, proper termination must be used; for example, a 50Ω
test environment should be terminated into a 50Ω load with 1.73V
(Thevenin Voltage) at the comparator input, and a 116Ω resistor must
be used in series with D
OUT
to match 166Ω (Thevenin Resistance).
Document #
SRAM127
REV E
Page 6 of 10
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