54ABT373
Octal Transparent Latch with TRI-STATE®Outputs
General Description
The ’ABT373 consists of eight latches with TRI-STATE out-
puts for bus organized system applications. The flip-flops ap-
pear transparent to the data when Latch Enable (LE) is
HIGH. When LE is LOW, the data that meets the setup times
is latched. Data appears on the bus when the Output Enable
(OE) is LOW. When OE is HIGH the bus output is in the high
impedance state.
Features
nTRI-STATE outputs for bus interfacing
nOutput sink capability of 48 mA, source capability of
24 mA
nGuaranteed multiple output switching specifications
nOutput switching specified for both 50 pF and 250 pF
loads
nGuaranteed simultaneous switching, noise level and
dynamic threshold performance
nGuaranteed latchup protection
nHigh impedance glitch free bus loading during entire
power up and power down
nNondestructive hot insertion capability
nStandard Microcircuit Drawing (SMD) 5962-9321801
Ordering Code
Military Package Number Package Description
54ABT373J-QML J20A 20-Lead Ceramic Dual-In-Line
54ABT373W-QML W20A 20-Lead Cerpack
54ABT373E-QML E20A 20-Lead Ceramic Leadless Chip Carrier, Type C
Connection Diagrams
Pin Names Description
D
0
–D
7
Data Inputs
LE Latch Enable Input
(Active HIGH)
OE Output Enable Input
(Active LOW)
O
0
–O
7
TRI-STATE Latch
Outputs
TRI-STATE®is a registered trademark of National Semiconductor Corporation.
Pin Assignment
for DIP and Flatpak
DS100206-1
Pin Assignment
for LCC
DS100206-2
July 1998
54ABT373 Octal Transparent Latch with TRI-STATE Outputs
© 1998 National Semiconductor Corporation DS100206 www.national.com
Functional Description
The ’ABT373 contains eight D-type latches with TRI-STATE
output buffers. When the Latch Enable (LE) input is HIGH,
data on the D
n
inputs enters the latches. In this condition the
latches are transparent, i.e., a latch output will change state
each time its D input changes. When LE is LOW, the latches
store the information that was present on the D inputs a
setup time preceding the HIGH-to-LOW transition of LE. The
TRI-STATE buffers are controlled by the Output Enable (OE)
input. When OE is LOW, the buffers are in the bi-state mode.
When OE is HIGH the buffers are in the high impedance
mode but this does not interfere with entering new data into
the latches.
Truth Table
Inputs Output
LE OE D
n
O
n
HLH H
HLL L
LLXO
n
(no change)
XHX Z
H
=
HIGH Voltage Level
L=LOW Voltage Level
X=Immaterial
Z=High Impedance State
Logic Diagram
DS100206-3
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature −65˚C to +150˚C
Ambient Temperature under Bias −55˚C to +125˚C
Junction Temperature under Bias
Ceramic −55˚C to +175˚C
V
CC
Pin Potential to
Ground Pin −0.5V to +7.0V
Input Voltage (Note 2) −0.5V to +7.0V
Input Current (Note 2) −30 mA to +5.0 mA
Voltage Applied to Any Output
in the Disabled or
Power-Off State −0.5V to +5.5V
in the HIGH State −0.5V to V
CC
Current Applied to Output
in LOW State (Max) twice the rated I
OL
(mA)
Over Voltage Latchup (I/O) 10V
Recommended Operating
Conditions
Free Air Ambient Temperature
Military −55˚C to +125˚C
Supply Voltage
Military +4.5V to +5.5V
Minimum Input Edge Rate (∆V/∆t)
Data Input 50 mV/ns
Enable Input 20 mV/ns
Note 1: Absolute maximum ratings are values beyond which the device may
be damaged or have its useful life impaired. Functional operation under these
conditions is not implied.
Note 2: Either voltage limit or current limit is sufficient to protect inputs.
DC Electrical Characteristics
Symbol Parameter ABT373 Units VCC Conditions
Min Typ Max
VIH Input HIGH Voltage 2.0 V Recognized HIGH Signal
VIL Input LOW Voltage 0.8 V Recognized LOW Signal
VCD Input Clamp Diode Voltage −1.2 V Min IIN =−18 mA
VOH Output HIGH Voltage 54ABT 2.5 IOH =−3 mA
54ABT 2.0 V Min IOH =−24 mA
VOL Output LOW Voltage 54ABT 0.55 V Min IOL =48 mA
IIH Input HIGH Current 5 µA Max VIN =2.7V (Note 4)
5V
IN =VCC
IBVI Input HIGH Current Breakdown Test 7 µA Max VIN =7.0V
IIL Input LOW Current −5 µA Max VIN =0.5V (Note 4)
−5 VIN =0.0V
VID Input Leakage Test 4.75 V 0.0 IID =1.9 µA
All Other Pins Grounded
IOZH Output Leakage Current 50 µA 0 − 5.5V VOUT =2.7V; OE =2.0V
IOZL Output Leakage Current −50 µA 0 − 5.5V VOUT =0.5V; OE =2.0V
IOS Output Short-Circuit Current −100 −275 mA Max VOUT =0.0V
ICEX Output High Leakage Current 50 µA Max VOUT =VCC
IZZ Bus Drainage Test 100 µA 0.0 VOUT =5.5V; All Others GND
ICCH Power Supply Current 50 µA Max All Outputs HIGH
ICCL Power Supply Current 30 mA Max All Outputs LOW
ICCZ Power Supply Current 50 µA Max OE =VCC
All Others at VCC or GND
ICCT Additional ICC/Input Outputs Enabled 2.5 mA VI=VCC − 2.1V
Outputs TRI-STATE 2.5 mA Max Enable Input VI=VCC − 2.1V
Outputs TRI-STATE 2.5 mA Data Input VI=VCC − 2.1V
All Others at VCC or GND
ICCD Dynamic ICC No Load mA/ Max Outputs Open, LE =VCC
(Note 4) 0.12 MHz OE =GND, (Note 3)
One Bit Toggling, 50%Duty Cycle
Note 3: For 8 bits toggling, ICCD <0.8 mA/MHz.
Note 4: Guaranteed, but not tested.
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AC Electrical Characteristics
Symbol Parameter 54ABT Units
T
A
=−55˚C to +125˚C
V
CC
=4.5V to 5.5V
C
L
=50 pF
Min Max
t
PLH
Propagation Delay 1.0 6.8 ns
t
PHL
D
n
to O
n
1.0 7.0
t
PLH
Propagation Delay 1.0 7.7 ns
t
PHL
LE to O
n
1.5 7.7
t
PZH
Output Enable Time 1.0 6.7 ns
t
PZL
1.5 7.2
t
PHZ
Output Disable Time 1.7 8.0 ns
t
PLZ
1.0 7.0
AC Operating Requirements
Symbol Parameter 54ABT Units
T
A
=−55˚C to +125˚C
V
CC
=4.5V to 5.5V
C
L
=50 pF
Min Max
t
s
(H) Setup Time, HIGH 2.5 ns
t
s
(L) or LOW D
n
to LE 2.5
t
h
(H) Hold Time, HIGH 2.5 ns
t
h
(L) or LOW D
n
to LE 2.5
t
w
(H) Pulse Width, 3.3 ns
LE HIGH
Capacitance
Symbol Parameter Typ Units Conditions
(T
A
=25˚C)
C
IN
Input Capacitance 5 pF V
CC
=0V
C
OUT
(Note 5) Output Capacitance 9 pF V
CC
=5.0V
Note 5: COUT is measured at frequency f =1 MHz, per MIL-STD-883B, Method 3012.
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
PLH
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to Output
DS100206-11
t
PHL
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to Output
DS100206-12
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Capacitance (Continued)
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
PZH
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
OE to Output
DS100206-13
t
PZL
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
OE to Output
DS100206-14
t
PHZ
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
OE to Output
DS100206-15
t
PLZ
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
OE to Output
DS100206-16
t
SET
LOW vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to LE
DS100206-17
t
SET
HIGH vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to LE
DS100206-18
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Capacitance (Continued)
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
HOLD
HIGH vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to LE
DS100206-19
t
HOLD
LOW vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
Data to LE
DS100206-20
t
PLH
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
Data to Output
DS100206-21
t
PHL
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
Data to Output
DS100206-22
t
PZH
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
OE to Output
DS100206-23
t
PZL
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
OE to Output
DS100206-24
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Capacitance (Continued)
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
PHZ
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
OE to Output
DS100206-25
t
PLZ
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
OE to Output
DS100206-26
t
PLH
vs Load Capacitance
T
A
=25˚C, 1 Output Switching
Data to Output
DS100206-27
t
PHL
vs Load Capacitance
T
A
=25˚C, 1 Output Switching
Data to Output
DS100206-28
t
PLH
vs Load Capacitance
T
A
=25˚C, 8 Outputs Switching
Data to Output
DS100206-29
t
PHL
vs Load Capacitance
T
A
=25˚C, 8 Outputs Switching
Data to Output
DS100206-30
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Capacitance (Continued)
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
PZH
vs Load Capacitance
T
A
=25˚C, 8 Outputs Switching
OE to Output
DS100206-31
t
PZL
vs Load Capacitance
T
A
=25˚C, 8 Outputs Switching
OE to Output
DS100206-32
t
PLH
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
LE to Output
DS100206-35
t
PHL
vs Temperature (T
A
)
C
L
=50 pF, 1 Output Switching
LE to Output
DS100206-36
t
PLH
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
LE to Output
DS100206-37
t
PHL
vs Temperature (T
A
)
C
L
=50 pF, 8 Outputs Switching
LE to Output
DS100206-38
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Capacitance (Continued)
Dashed lines represent design characteristics; for specified guarantees, refer to AC Characteristics Tables.
t
PLH
and t
PHL
vs Number Outputs Switching
C
L
=50 pF, T
A
=25˚C, V
CC
=5.0V,
Outputs In Phase Data to Output
DS100206-33
Typical I
CC
vs Output Switching Frequency
C
L
=0pF,V
CC
=V
IH
=5.5V, LE =GND,
1 Output Switching at 50%Duty Cycle
Data to Output, Transparent Mode with
Unused Data Inputs =V
IH
DS100206-34
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AC Loading
DS100206-4
*Includes jig and probe capacitance
FIGURE 1. Standard AC Test Load
DS100206-6
FIGURE 2. Test Input Signal Levels
Amplitude Rep. Rate t
w
t
r
t
f
3.0V 1 MHz 500 ns 2.5 ns 2.5 ns
FIGURE 3. Test Input Signal Requirements
DS100206-8
FIGURE 4. Propagation Delay Waveforms for
Inverting and Non-Inverting Functions
DS100206-5
FIGURE 5. Propagation Delay,
Pulse Width Waveforms
DS100206-7
FIGURE 6. TRI-STATE Output HIGH
and LOW Enable and Disable Times
DS100206-9
FIGURE 7. Setup Time, Hold Time
and Recovery Time Waveforms
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11
Physical Dimensions inches (millimeters) unless otherwise noted
20-Terminal Ceramic Chip Carrier (L)
NS Package Number E20A
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Ceramic Dual-In-Line (D)
NS Package Number J20A
20-Lead Ceramic Flatpak (F)
NS Package Number W20A
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the body, or (b) support or sustain life, and whose fail-
ure to perform when properly used in accordance
with instructions for use provided in the labeling, can
be reasonably expected to result in a significant injury
to the user.
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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54ABT373 Octal Transparent Latch with TRI-STATE Outputs
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
