ꢀ ꢁꢂ ꢃꢄ ꢄ ꢅ ꢆ ꢀꢁ ꢂ ꢃꢇ ꢀꢄ ꢄ ꢅꢆ ꢀ ꢁꢈ ꢃ ꢄꢄ ꢅ ꢆ ꢀ ꢁꢈ ꢃ ꢇ ꢀꢄ ꢄ ꢅ
ꢉ ꢊꢋꢇ ꢌ ꢍꢁꢍ ꢀꢎꢋꢏ ꢇꢐ ꢌꢊ ꢇꢎꢑ ꢒ ꢑ ꢏ ꢓꢋꢎꢍ ꢓꢀ
ꢔꢑ ꢎ ꢕ ꢀꢖ ꢕ ꢌꢑ ꢎ ꢎꢗꢎ ꢓꢑ ꢘ ꢘꢐ ꢓ ꢑ ꢁꢙ ꢊꢎ ꢀ
SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54LS221
SN74LS221
†
PARAMETER
UNIT
V
TEST CONDITIONS
‡
‡
MIN TYP
MAX
MIN TYP
MAX
Positive-going threshold voltage,
B input
V
V
V
V
= MIN
1
2*
1
2
T+
CC
Negative-going threshold voltage,
B input
= MIN
0.7*
2.5
0.9
0.8
2.7
0.9
V
T−
CC
V
V
V
V
= MIN,
= MIN,
I = −18 mA
−1.5
0.4
−1.5
V
V
IK
CC
I
I
I
I
= −400 µA
= 4 mA
3.4
3.4
0.25
0.35
OH
CC
OH
OL
OL
0.25
0.4
0.5
V
OL
V
CC
= MIN
V
= 8 mA
I
I
V
V
= MAX,
= MAX,
V = 7 V
I
0.1
20
0.1
mA
I
CC
V = 2.7 V
I
20
µA
CC
IH
A input
−0.4
−0.8
−100
11
−0.4
−0.8
−100
11
V
CC
V
CC
V
CC
= MAX,
= MAX
= MAX
V = 0.4 V
I
mA
mA
mA
I
I
I
IL
CLR, B input
§
−20
−20
OS
CC
Quiescent
Triggered
4.7
19
4.7
19
27*
27
∗ On products compliant to MIL-PRF-38535, this parameter is not production tested.
†
‡
§
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
All typical values are at V = 5 V, T = 25°C.
CC
A
Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.
timing requirements over recommended ranges of supply voltage and operating free-air
temperature
SN54LS221
SN74LS221
UNIT
MIN
50
MAX
MIN
50
40
15
1.4
0
MAX
A or B
CLR
t
t
Pulse duration
ns
w
40
¶
CLR
15
ns
kΩ
µF
Setup time, inactive state
su
R
C
1.4*
70*
100
1000
50%
90%
External timing resistance
External timing capacitance
ext
ext
0* 1000*
50%
R
R
= 2 kΩ
T
Output duty cycle
= MAX R
90%
T
ext
∗ On products compliant to MIL-PRF-38535, this parameter is not production tested.
¶
Inactive-state setup time also is referred to as recovery time.
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
