Page 1
QUAD SET-RESET LATCH
SN54/74LS279
S
V
1
CC
16 15
123456
S
R
1
QS
R
14 13 12 11 10 9
S
QRS
2
S
1
2Q
1
TRUTH TABLE
INPUT
S1S2R
L
L
L
X
X
L
H
H
H
H
L = LOW Voltage Level
H = HIGH Voltage Level
X = Don’t Care
h = The output is HIGH as long as
h = S1 or S2 is LOW. If all inputs go
h = HIGH simultaneously , the output
h = state is indeterminate; otherwise,
h = it follows the Truth Table
L
H
H
L
H
OUTPUT
(Q)
h
H
H
L
No Change
R
7
Q GND
QUAD SET-RESET LATCH
LOW POWER SCHOTTKY
8
16
1
16
1
16
1
ORDERING INFORMATION
SN54LSXXXJ Ceramic
SN74LSXXXN Plastic
SN74LSXXXD SOIC
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
D SUFFIX
SOIC
CASE 751B-03
GUARANTEED OPERATING RANGES
Symbol Parameter Min Typ Max Unit
V
T
I
I
CC
A
OH
OL
Supply Voltage 54
74
Operating Ambient Temperature Range 54
74
Output Current — High 54, 74 –0.4 mA
Output Current — Low 54
74
4.5
4.75
–55
0
5.0
5.0
25
25
5.5
5.25
125
70
4.0
8.0
FAST AND LS TTL DATA
5-1
V
°C
mA
Page 2
SN54/74LS279
VILInput LOW Voltage
V
g
VOHOutput HIGH Voltage
CC OH IN IH
VOLOutput LOW Voltage
V
IN
V
IL
V
IH
IIHInput HIGH Current
C
L
F
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol Parameter
V
IH
V
IK
I
IL
I
OS
I
CC
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
Input HIGH Voltage 2.0 V
p
Input Clamp Diode Voltage –0.65 –1.5 V VCC = MIN, IIN = –18 mA
p
p
p
Input LOW Current –0.4 mA VCC = MAX, VIN = 0.4 V
Short Circuit Current (Note 1) –20 –100 mA VCC = MAX
Power Supply Current 7.0 mA VCC = MAX
54
74
54 2.5 3.5 V
74 2.7 3.5 V
54, 74 0.25 0.4 V IOL = 4.0 mA
74 0.35 0.5 V IOL = 8.0 mA
Min Typ Max
0.7
0.8
20 µA VCC = MAX, VIN = 2.7 V
0.1 mA VCC = MAX, VIN = 7.0 V
Unit Test Conditions
Guaranteed Input HIGH Voltage for
All Inputs
Guaranteed Input LOW Voltage for
All Inputs
VCC = MIN, IOH = MAX, VIN = V
or VIL per Truth Table
IH
VCC = VCC MIN,
=
per Truth Table
or
AC CHARACTERISTICS (T
Symbol Parameter
t
PLH
t
PHL
t
PHL
* Add 0.6 ns to spec limit for each 1.0 ns input rise time less than 15 ns.
Propagation Delay, S to Output
Propagation Delay, R to Output 27 ns
= 25°C)
A
Min Typ Max
Limits
22
*21*
Unit Test Conditions
ns
VCC = 5.0 V
= 15
p
FAST AND LS TTL DATA
5-2
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