DM74AS573 Octal D-Type Transparent Latch with 3-STATE Outputs
October 1986
Revised March 2000
DM74AS573
Octal D-Type Transparent Latch with 3-STATE Outputs
General Description
These 8-bit registers feature totem-pole 3-STATE outputs
designed specifically for driving highly-capacitive or rela-
tively low-impedance loads. The high-impedance state and
increased HIGH-logic-level drive provide these registers
with the capability of being connected directly to and driv-
ing the bus lines in a bus-organized system without need
for interface or pull-up components. They are particularly
attractive for implementing buffer registers, I/O ports, bidi-
rectional bus drivers, and working registers.
The eight latches of the DM74AS573 are transparent D-
type latches, meaning that while the enable (G) is HIGH
the Q outputs will follow the data (D) inputs. When the
enable is taken LOW the output will be latched at the level
of the data that was set UP.
A buffered output control input can be used to place the
eight outputs in either a normal logic state (HIGH or LOW
logic levels) or a high-impedance state. In the high-imped-
ance state the outputs neither load nor drive the bus lines
significantly.
The output control does not affect the internal operation of
the latches. That is, the old data can be retained or new
data can be entered even while the outputs are OFF.
The pin-out is arranged to ease printed circuit board layout.
All data inputs are on one side of the package while all the
outputs are on the other side.
Features
s
Switching specifications at 50 pF
s
Switching specifications guaranteed over full tempera-
ture and V
CC
range
s
Advanced oxide-isolated, ion-implanted Schottky TTL
process
s
Functionally equivalent with DM74S373
s
Improved AC performance over DM74S373 at approxi-
mately half the power
s
3-STATE buffer-type outputs drive bus lines directly
s
Bus structured pinout
Ordering Code:
Order Number
DM74AS573WM
DM74AS573N
Package Number
M20B
N20A
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
© 2000 Fairchild Semiconductor Corporation
DS006313
www.fairchildsemi.com
DM74AS573
Absolute Maximum Ratings
(Note 1)
Supply Voltage
Input Voltage
Voltage Applied to Disabled Output
Operating Free Air Temperature Range
Storage Temperature Range
Typical
θ
JA
N Package
M Package
52.0°C/W
70.0°C/W
7V
7V
5.5V
0°C to
+70°C
−65°C
to
+150°C
Note 1:
The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Symbol
V
CC
V
IH
V
IL
I
OH
I
OL
t
W
t
SU
t
H
T
A
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Width of Enable Pulse
Data Setup Time (Note 2)
Data Hold Time (Note 2)
Free Air Operating Temperature
HIGH
LOW
4.5
5.5
2↑
3↑
0
70
Parameter
Min
4.5
2
0.8
−15
48
Nom
5
Max
5.5
Units
V
V
V
mA
mA
ns
ns
ns
°C
Note 2:
The (↑) arrow indicates the positive edge of the Clock is used for reference.
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at V
CC
=
5V, T
A
=
25°C.
Symbol
V
IK
V
OH
V
OL
I
I
I
IH
I
IL
I
O
(Note 3)
I
OZH
I
OZL
I
CC
Parameter
Input Clamp Voltage
HIGH Level
Output Voltage
LOW Level
Output Voltage
HIGH Level Input Current
LOW Level Input Current
Output Drive Current
OFF-State Output Current,
HIGH Level Voltage Applied
Off-State Output Current,
Low Level Voltage Applied
Supply Current
Conditions
V
CC
=
4.5V, I
I
= −18
mA
V
CC
=
4.5V, V
IL
=
Max, I
OH
=
Max
V
CC
=
4.5V to 5.5V, I
OH
= −2
mA
V
CC
=
4.5V, V
IH
=
2V
I
OL
=
Max
V
CC
=
5.5V, V
IH
=
2.7V
V
CC
=
5.5V, V
IL
=
0.4V
V
CC
=
5.5V, V
O
=
2.25V
V
CC
=
5.5V, V
IH
=
2V,
V
O
=
2.7V
V
CC
=
5.5V, V
IH
=
2V,
V
O
=
0.4V
V
CC
=
5.5V
Outputs Open
Outputs HIGH
Outputs LOW
Outputs Disabled
56
55
65
−30
2.4
V
CC
−
2
0.35
0.5
0.1
20
−0.5
−112
50
−50
93
90
106
mA
3.3
Min
Typ
Max
−1.2
Units
V
V
V
mA
µA
mA
mA
µA
µA
Input Current @ Max Input Voltage V
CC
=
5.5V, V
IH
=
7V
Note 3:
The output conditions have been chosen to produce a current that approximates one half of the true short-circuit output current, I
OS
.
3
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