Datenblatt-pdf.com


74ACTQ843 Schematic ( PDF Datasheet ) - Fairchild Semiconductor

Teilenummer 74ACTQ843
Beschreibung Quiet Seriesa 9-Bit Transparent Latch with 3-STATE Outputs
Hersteller Fairchild Semiconductor
Logo Fairchild Semiconductor Logo 




Gesamt 8 Seiten
74ACTQ843 Datasheet, Funktion
March 1990
Revised December 1998
74ACTQ843
Quiet Series9-Bit Transparent Latch
with 3-STATE Outputs
General Description
The ACTQ843 bus interface latch is designed to eliminate
the extra packages required to buffer existing latches and
provide extra data width for wider address/data paths. The
ACTQ843 utilizes Fairchild FACT Quiet Seriestechnol-
ogy to guarantee quiet output switching and improved
dynamic threshold performance. FACT Quiet Series fea-
tures GTOoutput control and undershoot corrector in
addition to a split ground bus for superior performance.
Features
s Guaranteed simultaneous switching noise level and
dynamic threshold performance
s Guaranteed pin-to-pin skew AC performance
s Inputs and outputs on opposite sides of package for
easy interface with microprocessors
s Improved latch-up immunity
s Outputs source/sink 24 mA
s ACTQ843 has TTL-compatible inputs
s Functionally and pin-compatible to AMD’s AM29843
s 3-STATE outputs for bus interfacing
Ordering Code:
Order Number Package Number
Package Description
74ACTQ843SC
M24B
24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
74ACTQ843SPC
N24C
24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-100, 0.300” Wide
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Logic Symbols
Connection Diagram
Pin Assignment for DIP and SOIC
Pin Descriptions
Pin Names
D0–D8
O0–O8
OE
LE
CLR
PRE
Description
Data Inputs
Data Outputs
Output Enable
Latch Enable
Clear
Preset
FACT, Quiet Series, FACT Quiet Seriesand GTOare trademarks of Fairchild Semiconductor Corporation.
© 1999 Fairchild Semiconductor Corporation DS010689.prf
www.fairchildsemi.com






74ACTQ843 Datasheet, Funktion
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:
Hewlett Packard Model 8180A Word Generator
PC-163A Test Fixture
Tektronics Model 7854 Oscilloscope
Procedure:
1. Verify Test Fixture Loading: Standard Load 50 pF,
500.
2. Deskew the HFS generator so that no two channels
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.
3. Terminate all inputs and outputs to ensure proper load-
ing of the outputs and that the input levels are at the
correct voltage.
4. Set the HFS generator to toggle all but one output at a
frequency of 1 MHz. Greater frequencies will increase
DUT heating and effect the results of the measure-
ment.
5. Set the HFS generator input levels at 0V LOW and 3V
HIGH for ACT devices and 0V LOW and 5V HIGH for
AC devices. Verify levels with an oscilloscope.
VOLP/VOLV and VOHP/V OHV:
• Determine the quiet output pin that demonstrates the
greatest noise levels. The worst case pin will usually be
the furthest from the ground pin. Monitor the output volt-
ages using a 50coaxial cable plugged into a standard
SMB type connector on the test fixture. Do not use an
active FET probe.
• Measure VOLP and VOLV on the quiet output during the
worst case transition for active and enable. Measure
VOHP and VOHV on the quiet output during the worst
case active and enable transition.
• Verify that the GND reference recorded on the oscillo-
scope has not drifted to ensure the accuracy and repeat-
ability of the measurements.
VILD and VIHD:
• Monitor one of the switching outputs using a 50coaxial
cable plugged into a standard SMB type connector on
the test fixture. Do not use an active FET probe.
• First increase the input LOW voltage level, VIL, until 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 VIL limits, or on output HIGH levels that
exceed VIH limits. The input LOW voltage level at which
oscillation occurs is defined as VILD.
• Next decrease the input HIGH voltage level on the, VIH,
until 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 VIL limits, or on output HIGH levels
that exceed VIH limits. The input HIGH voltage level at
which oscillation occurs is defined as VIHD.
• Verify that the GND reference recorded on the oscillo-
scope has not drifted to ensure the accuracy and repeat-
ability of the measurements.
FIGURE 1. Quiet Output Noise Voltage Waveforms
Note 10: VOHV and VOLP are measured with respect to ground reference.
Note 11: Input pulses have the following characteristics: f = 1 MHz,
tr = 3 ns, tf = 3 ns, skew < 150 ps.
FIGURE 2. Simultaneous Switching Test Circuit
www.fairchildsemi.com
6

6 Page







SeitenGesamt 8 Seiten
PDF Download[ 74ACTQ843 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
74ACTQ841Quiet Seriesa 10-Bit Transparent Latch with 3-STATE OutputsFairchild Semiconductor
Fairchild Semiconductor
74ACTQ843Quiet Seriesa 9-Bit Transparent Latch with 3-STATE OutputsFairchild Semiconductor
Fairchild Semiconductor
74ACTQ843SCQuiet Seriesa 9-Bit Transparent Latch with 3-STATE OutputsFairchild Semiconductor
Fairchild Semiconductor
74ACTQ843SPCQuiet Seriesa 9-Bit Transparent Latch with 3-STATE OutputsFairchild Semiconductor
Fairchild Semiconductor

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche