SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004
SN54221, SN54LS221, SN74221, SN74LS221
DUAL MONOSTABLE MULTIVIBRATORS
WITH SCHMITT TRIGGER INPUTS
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VT+
VT−
VIK
VOH
VOL
II
IIH
A input
IIL
IOS§
ICC
Quiescent
Triggered
CLR, B input
VCC = MAX,
VCC = MAX
VCC = MAX
VI = 0.4 V
−20
4.7
19
Positive-going threshold voltage,
B input
Negative-going threshold voltage,
B input
TEST CONDITIONS†
VCC = MIN
VCC = MIN
VCC = MIN,
VCC = MIN,
VCC = MIN
VCC = MAX,
VCC = MAX,
II = −18 mA
IOH = −400
µA
IOL = 4 mA
IOL = 8 mA
VI = 7 V
VI = 2.7 V
0.7*
SN54LS221
MIN TYP‡
MAX
1
0.9
−1.5
2.5
3.4
0.25
0.4
0.1
20
−0.4
−0.8
−100
11
27*
−20
4.7
19
2.7
3.4
0.25
0.35
0.4
0.5
0.1
20
−0.4
−0.8
−100
11
27
mA
mA
mA
V
mA
µA
2*
0.8
SN74LS221
MIN TYP‡
MAX
1
0.9
−1.5
2
UNIT
V
V
V
V
∗
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 VCC = 5 V, TA = 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
MIN
A or B
tw
tsu
Rext
Cext
Pulse duration
Setup time, inactive state¶
External timing resistance
External timing capacitance
Output duty cycle
RT = 2 kΩ
RT = MAX Rext
CLR
CLR
50
40
15
1.4*
0*
70*
1000*
50%
90%
MAX
SN74LS221
MIN
50
40
15
1.4
0
100
1000
50%
90%
ns
ns
kΩ
µF
MAX
UNIT
∗
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 ]
