74ACTQ02 Fairchild Semiconductor, 74ACTQ02 Datasheet - Page 4

• Manufacturer Part Number: 74ACTQ02
• Description: Quad 2-Input NOR Gate
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
FACT Noise Characteristics
The setup of a noise characteristics measurement is critical
to the accuracy and repeatability of the tests. The following
is a brief description of the setup used to measure the
noise characteristics of FACT.
Equipment:
Procedure:
1. Verify Test Fixture Loading: Standard Load 50 pF,
2. Deskew the HFS generator so that no two channels
3. Terminate all inputs and outputs to ensure proper load-
4. Set the HFS generator to toggle all but one output at a
5. Set the HFS generator input levels at 0V LOW and 3V
Hewlett Packard Model 8180A Word Generator
PC-163A Test Fixture
Tektronics Model 7854 Oscilloscope
500 .
have greater than 150 ps skew between them. This
requires that the oscilloscope be deskewed first. It is
important to deskew the HFS generator channels
before testing. This will ensure that the outputs switch
simultaneously.
ing of the outputs and that the input levels are at the
correct voltage.
frequency of 1 MHz. Greater frequencies will increase
DUT heating and affect the results of the measure-
ment.
Note 9: V
ence.
Note 10: Input pulses have the following characteristics: f
t
HIGH for ACT devices and 0V LOW and 5V HIGH for
AC devices. Verify levels with an oscilloscope.
r
FIGURE 1. Quiet Output Noise Voltage Waveforms
3 ns, t
f
OHV
3 ns, skew
and V
OLP
are measured with respect to ground refer-
150 ps.
1 MHz,
4
V
• Determine the quiet output pin that demonstrates the
• Measure V
• Verify that the GND reference recorded on the oscillo-
V
• Monitor one of the switching outputs using a 50 coaxial
• First increase the input LOW voltage level, V
• Next decrease the input HIGH voltage level, V
• Verify that the GND reference recorded on the oscillo-
OLP
ILD
greatest noise levels. The worst case pin will usually be
the furthest from the ground pin. Monitor the output volt-
ages using a 50
SMB type connector on the test fixture. Do not use an
active FET probe.
worst case transition for active and enable. V
V
for active and enable.
scope has not drifted to ensure the accuracy and repeat-
ability of the measurements.
cable plugged into a standard SMB type connector on
the test fixture. Do not use an active FET probe.
output begins to oscillate or steps out a min of 2 ns.
Oscillation is defined as noise on the output LOW level
that exceeds V
exceed V
oscillation occurs is defined as V
the output begins to oscillate or steps out a min of 2 ns.
Oscillation is defined as noise on the output LOW level
that exceeds V
exceed V
oscillation occurs is defined as V
scope has not drifted to ensure the accuracy and repeat-
ability of the measurements.
OHV
FIGURE 2. Simultaneous Switching Test Circuit
and V
/V
OLV
on the quiet output during the worst case transition
IHD
and V
IH
IH
OLP
:
limits. The input LOW voltage level at which
limits. The input HIGH voltage level at which
OHP
and V
IL
IL
limits, or on output HIGH levels that
limits, or on output HIGH levels that
/V
coaxial cable plugged into a standard
OHV
OLV
:
on the quiet output during the
ILD
IHD
.
.
IL
, until the
OHP
IH
, until
and