Datasheet
SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
†
SN54LS221 SN74LS221
UNIT
PARAMETER
TEST CONDITIONS
†
MIN TYP
‡
MAX MIN TYP
‡
MAX
UNIT
V
T+
Positive-going threshold voltage,
B input
V
CC
= MIN 1 2* 1 2 V
V
T−
Negative-going threshold voltage,
B input
V
CC
= MIN 0.7* 0.9 0.8 0.9 V
V
IK
V
CC
= MIN, I
I
= −18 mA −1.5 −1.5 V
V
OH
V
CC
= MIN, I
OH
= −400 µA 2.5 3.4 2.7 3.4 V
V
OL
V
CC
= MIN
I
OL
= 4 mA 0.25 0.4 0.25 0.4
V
V
OL
V
CC
= MIN
I
OL
= 8 mA 0.35 0.5
V
I
I
V
CC
= MAX, V
I
= 7 V 0.1 0.1 mA
I
IH
V
CC
= MAX, V
I
= 2.7 V 20 20 µA
I
IL
A input
V
CC
= MAX,
V
I
= 0.4 V
−0.4 −0.4
mA
I
IL
CLR, B input
V
CC
= MAX, V
I
= 0.4 V
−0.8 −0.8
mA
I
OS
§
V
CC
= MAX −20 −100 −20 −100 mA
I
CC
Quiescent
V
CC
= MAX
4.7 11 4.7 11
mA
I
CC
Triggered
V
CC
= MAX
19 27* 19 27
mA
∗ 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
CC
= 5 V, T
A
= 25°C.
§
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 MAX MIN MAX
UNIT
t
w
Pulse duration
A or B 50 50
ns
t
w
Pulse duration
CLR
40 40
ns
t
su
Setup time, inactive state
¶
CLR 15 15 ns
R
ext
External timing resistance
1.4* 70* 1.4 100 kΩ
C
ext
External timing capacitance
0* 1000* 0 1000 µF
Output duty cycle
R
T
= 2 kΩ 50% 50%
Output duty cycle
R
T
= MAX R
ext
90% 90%
∗ On products compliant to MIL-PRF-38535, this parameter is not production tested.
¶
Inactive-state setup time also is referred to as recovery time.