HD74LS221

Rev.3.00, Jul.15.2005, page 3 of 8

Absolute Maximum Ratings

Item

Symbol

Ratings

Unit

Supply voltage

7

V

Input voltage

7

V

Power dissipation

400

mW

Storage temperature

Tstg

–65 to +150

°C

Note:

Voltage value, unless otherwise noted, are with respect to network ground terminal.

Recommended Operating Conditions

Item

Symbol

Min

Typ

Max

Unit

Supply voltage

4.75

5.00

5.25

V

—

—

–400

µA

Output current

—

—

8

mA

Operating temperature

–20

25

75

°C

Schmitt input, B

1

—

—

V/s

Rate of rise or fall of

input pulse

Logic Input, A

dV/dt

1

—

—

V/

µs

A or B

40

—

—

Input pulse width

Clear

40

—

—

ns

Setup time

15

—

—

ns

External timing resistance

1.4

—

100

k

Ω

External timing capacitance

0

—

1000

µF

Ω

—

—

50

Duty cycle

Ω

—

—

90

Electrical Characteristics

(Ta = –20 to +75 °C)

Item

Symbol

min.

typ.*

max.

Unit

Condition

+

—

1.0

2.0

V

A

–

0.8

1.0

—

V

+

—

1.0

2.0

V

Threshold

voltage

B

–

0.8

0.9

—

V

2.7

—

—

V

µA

—

—

0.4

Output voltage

—

—

0.5

V

—

—

20

µA

A

—

—

–0.4

B, Clear

—

—

–0.8

mA

Input current

—

—

0.1

mA

Short-circuit output

current

–20

—

–100

mA

—

4.7

11

Ouiescent

Supply current

—

19

27

mA

Triggered

Input clamp voltage

—

—

–1.5

V

Note: