SN54221, SN54LS221, SN74221, SN74LS221

DUAL MONOSTABLE MULTIVIBRATORS

WITH SCHMITT TRIGGER INPUTS

SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004

6

POST OFFICE BOX 655303

electrical characteristics over recommended operating free-air temperature range (unless

otherwise noted)

PARAMETER

TEST CONDITIONS†

SN54221

SN74221

UNIT

PARAMETER

TEST CONDITIONS†

MIN

TYP‡

MAX

MIN

TYP‡

MAX

UNIT

VT+

Positive-going threshold voltage,

B input

VCC = MIN

1.55

2*

1.55

2

V

VT−

Negative-going threshold voltage,

B input

VCC = MIN

0.8*

1.35

0.8

1.35

V

VIK

VCC = MIN,

II = −12 mA

−1.5

−1.5

V

VOH

VCC = MIN,

IOH = −800 µA

2.4

3.4

2.4

3.4

V

VOL

VCC = MIN,

IOL = 16 mA

0.2

0.4

0.2

0.4

V

II

VCC = MAX,

VI = 5.5 V

1

1

mA

IIH

A input

VCC = MAX,

VI = 2.4 V

40

40

A

IIH

CLR, B input

VCC = MAX,

VI = 2.4 V

80

80

µA

IIL

A input

VCC = MAX,

VI = 0.4 V

−1.6

−1.6

mA

IIL

CLR, B input

VCC = MAX,

VI = 0.4 V

−3.2

−3.2

mA

IOS§

VCC = MAX

−20

−55

−18

−55

mA

ICC

Quiescent

VCC = MAX

26

50*

26

50

mA

ICC

Triggered

VCC = MAX

46

80*

46

80

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 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

SN54221

SN74221

UNIT

MIN

MAX

MIN

MAX

UNIT

tw

Pulse duration

A or B input

50

50

ns

tw

Pulse duration

CLR

20

20

ns

tsu

Setup time, inactive-state¶

CLR

15

15

ns

Rext

External timing resistance

1.4*

30*

1.4

40

k

Ω

Cext

External timing capacitance

0*

1000*

0

1000

µF

Output duty cycle

Rext = 2 kΩ

67%

67%

Output duty cycle

Rext = MAX Rext

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.