SN74LS273
Octal D Flip-Flop
with Clear
The SN74LS273 is a high-speed 8-Bit Register. The register
consists of eight D-Type Flip-Flops with a Common Clock and an
asynchronous active LOW Master Reset. This device is supplied in a
20-pin package featuring 0.3 inch lead spacing.
http://onsemi.com
•
•
•
•
8-Bit High Speed Register
Parallel Register
Common Clock and Master Reset
Input Clamp Diodes Limit High-Speed Termination Effects
LOW
POWER
SCHOTTKY
GUARANTEED OPERATING RANGES
Symbol
V
CC
T
A
I
OH
I
OL
Parameter
Supply Voltage
Operating Ambient
Temperature Range
Output Current – High
Output Current – Low
Min
4.75
0
Typ
5.0
25
Max
5.25
70
– 0.4
8.0
Unit
V
°C
20
mA
mA
1
PLASTIC
N SUFFIX
CASE 738
20
1
SOIC
DW SUFFIX
CASE 751D
ORDERING INFORMATION
Device
SN74LS273N
SN74LS273DW
Package
16 Pin DIP
16 Pin
Shipping
1440 Units/Box
2500/Tape & Reel
©
Semiconductor Components Industries, LLC, 1999
1
December, 1999 – Rev. 6
Publication Order Number:
SN74LS273/D
SN74LS273
CONNECTION DIAGRAM DIP
(TOP VIEW)
V
CC
20
Q
7
19
D
7
18
D
6
17
Q
6
16
Q
5
15
D
5
14
D
4
13
Q
4
12
CP
11
1
MR
2
Q
0
3
D
0
4
D
1
5
Q
1
6
Q
2
7
D
2
8
D
3
9
Q
3
10
GND
LOADING
(Note a)
PIN NAMES
CP
D
0
– D
7
MR
Q
0
– Q
7
Clock (Active HIGH Going Edge) Input
Data Inputs
Master Reset (Active LOW) Input
Register Outputs
HIGH
0.5 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
LOW
0.25 U.L.
0.25 U.L.
0.25 U.L.
5 U.L.
NOTES:
a) 1 TTL Unit Load (U.L.) = 40
m
A HIGH/1.6 mA LOW.
TRUTH TABLE
MR
L
H
H
CP
X
D
x
X
H
L
Q
x
L
H
L
H = HIGH Logic Level
L = LOW Logic Level
X = Immaterial
LOGIC DIAGRAM
3
11
4
7
8
13
14
17
18
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
CP
CP D
CD Q
CP D
CD Q
CP D
CD Q
CP D
CD Q
CP D
CD Q
CP D
CD Q
CP D
CD Q
CP D
CD Q
1
MR
V
CC
= PIN 20
GND = PIN 10
= PIN NUMBERS
Q
0
2
Q
1
5
Q
2
6
Q
3
9
Q
4
12
Q
5
15
Q
6
16
Q
7
19
http://onsemi.com
2
SN74LS273
FUNCTIONAL DESCRIPTION
The SN74LS273 is an 8-Bit Parallel Register with a
common Clock and common Master Reset.
When the MR input is LOW, the Q outputs are LOW,
independent of the other inputs. Information meeting the
setup and hold time requirements of the D inputs is
transferred to the Q outputs on the LOW-to-HIGH transition
of the clock input.
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
V
IH
V
IL
V
IK
V
OH
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH Voltage
2.7
– 0.65
3.5
0.25
V
O
OL
Output LOW Voltage
0.35
I
IH
I
IL
I
OS
I
CC
Input HIGH Current
0.1
Input LOW Current
Short Circuit Current (Note 1)
Power Supply Current
– 20
– 0.4
– 100
27
0.5
20
V
µA
mA
mA
mA
mA
I
OL
= 8.0 mA
0.4
Min
2.0
0.8
– 1.5
Typ
Max
Unit
V
V
V
V
V
Test Conditions
Guaranteed Input HIGH Voltage for
All Inputs
Guaranteed Input LOW Voltage for
All Inputs
V
CC
= MIN, I
IN
= – 18 mA
V
CC
= MIN, I
OH
= MAX, V
IN
= V
IH
or V
IL
per Truth Table
I
OL
= 4.0 mA
V
CC
= V
CC
MIN,
V
IN
= V
IL
or V
IH
per Truth Table
V
CC
= MAX, V
IN
= 2.7 V
V
CC
= MAX, V
IN
= 7.0 V
V
CC
= MAX, V
IN
= 0.4 V
V
CC
= MAX
V
CC
= MAX
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS
(T
A
= 25°C, V
CC
= 5.0 V)
Limits
Symbol
f
MAX
t
PHL
t
PLH
t
PHL
Parameter
Maximum Input Clock Frequency
Propagation Delay, MR to Q Output
Propagation Delay, Clock to Output
Min
30
Typ
40
18
17
18
27
27
27
Max
Unit
MHz
ns
ns
Test Conditions
Figure 1
Figure 2
Figure 1
AC SETUP REQUIREMENTS
(T
A
= 25°C, V
CC
= 5.0 V)
Limits
Symbol
t
w
t
s
t
h
t
rec
Parameter
Pulse Width, Clock or Clear
Data Setup Time
Hold Time
Recovery Time
Min
20
20
5.0
25
Typ
Max
Unit
ns
ns
ns
ns
Test Conditions
Figure 1
Figure 1
Figure 1
Figure 2
http://onsemi.com
3
SN74LS273
AC WAVEFORMS
1/f max
t
W
CP
1.3 V
t
s
(H)
D
*
1.3 V
t
PLH
Q
n
1.3 V
t
PHL
*The shaded areas indicate when the input is permitted to
*change
for predictable output performance.
MR
1.3 V
t
h
(L)
1.3 V
1.3 V
t
PHL
1.3 V
t
PLH
Q
n
CP
t
W
1.3 V
t
rec
1.3 V
t
PHL
1.3 V
t
PLH
1.3 V
1.3 V
1.3 V
1.3 V
t
h
(H)
1.3 V
t
s
(L)
Q
n
Figure 1. Clock to Output Delays, Clock Pulse Width,
Frequency, Setup and Hold Times Data to Clock
DEFINITION OF TERMS
Figure 2. Master Reset to Output Delay, Master Reset
Pulse Width, and Master Reset Recovery Time
SETUP TIME (t
s
) — is defined as the minimum time
required for the correct logic level to be present at the logic
input prior to the clock transition from LOW-to-HIGH in
order to be recognized and transferred to the outputs.
HOLD TIME (t
h
) — is defined as the minimum time
following the clock transition from LOW-to-HIGH that the
logic level must be maintained at the input in order to ensure
continued recognition. A negative HOLD TIME indicates
that the correct logic level may be released prior to the clock
transition from LOW-to-HIGH and still be recognized.
RECOVERY TIME (t
rec
) — is defined as the minimum time
required between the end of the reset pulse and the clock
transition from LOW-to-HIGH in order to recognize and
transfer HIGH data to the Q outputs.
http://onsemi.com
4
SN74LS273
PACKAGE DIMENSIONS
N SUFFIX
PLASTIC PACKAGE
CASE 738–03
ISSUE E
–A–
20
11
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE MOLD
FLASH.
INCHES
MIN
MAX
1.010
1.070
0.240
0.260
0.150
0.180
0.015
0.022
0.050 BSC
0.050
0.070
0.100 BSC
0.008
0.015
0.110
0.140
0.300 BSC
0
_
15
_
0.020
0.040
MILLIMETERS
MIN
MAX
25.66
27.17
6.10
6.60
3.81
4.57
0.39
0.55
1.27 BSC
1.27
1.77
2.54 BSC
0.21
0.38
2.80
3.55
7.62 BSC
0
_
15
_
0.51
1.01
B
1
10
C
L
–T–
SEATING
PLANE
K
M
E
G
F
D
20 PL
N
J
0.25 (0.010)
M
20 PL
0.25 (0.010)
T A
M
M
T B
M
DIM
A
B
C
D
E
F
G
J
K
L
M
N
http://onsemi.com
5
