5-382

FAST AND LS TTL DATA

SN54/74LS221

GUARANTEED OPERATING RANGES

Symbol

Parameter

Min

Typ

Max

Unit

VCC

Supply Voltage

54

74

4.5

4.75

5.0

5.0

5.5

5.25

V

TA

Operating Ambient Temperature Range

54

74

– 55

0

25

25

125

70

°C

IOH

Output Current — High

54, 74

– 0.4

mA

IOL

Output Current — Low

54

74

4.0

8.0

mA

Symbol

Parameter

Limits

Unit

Test Conditions

Symbol

Parameter

Min

Typ

Max

Unit

Test Conditions

VT+

Positive-Going Threshold

Voltage at C Input

1.0

2.0

V

VCC = MIN

VT–

Negative-Going Threshold

Voltage at C Input

54

0.7

0.8

V

VCC = MIN

VT–

Negative-Going Threshold

Voltage at C Input

74

0.7

0.8

V

VCC = MIN

VT+

Positive-Going Threshold

Voltage at B Input

1.0

2.0

V

VCC = MIN

VT–

Negative-Going Threshold

Voltage at B Input

54

0.7

0.9

V

VCC = MIN

VT–

Negative-Going Threshold

Voltage at B Input

74

0.8

0.9

V

VCC = MIN

VIH

Input HIGH Voltage

2.0

V

Guaranteed Input HIGH Voltage for

A Input

VIL

Input LOW Voltage

54

0.7

V

Guaranteed Input LOW Voltage for

A Input

VIL

Input LOW Voltage

74

0.8

V

Guaranteed Input LOW Voltage for

A Input

VIK

Input Clamp Voltage

– 1.5

V

VCC = MIN, IIN = – 18 mA

VOH

Output HIGH Voltage

54

2.5

3.4

V

VCC = MIN, IOH = MAX

VOH

Output HIGH Voltage

74

2.7

3.4

V

VCC = MIN, IOH = MAX

VOL

Output LOW Voltage

54

0.25

0.4

V

IOL = 4.0 mA

VCC = MIN

VOL

Output LOW Voltage

74

0.35

0.5

V

IOL = 8.0 mA

VCC = MIN

IIH

Input HIGH Current

20

µA

VCC = MAX, VIN = 2.7 V

IIH

Input HIGH Current

0.1

mA

VCC = MAX, VIN = 7.0 V

IIL

Input LOW Current

Input A

Input B

Clear

– 0.4

– 0.8

– 0.8

mA

VCC = MAX, VIN = 0.4 V

IOS

Short Circuit Current (Note 1)

– 20

– 100

mA

VCC = MAX

ICC

Power Supply Current

Quiescent

4.7

11

mA

VCC = MAX

ICC

Triggered

19

27

mA

VCC = MAX

Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.