5-448

FAST AND LS TTL DATA

SN54/74LS273

FUNCTIONAL DESCRIPTION

The SN54 / 74LS273 is an 8-Bit Parallel Register with a

common Clock and common Master Reset.

When the MR input is LOW, the Q outputs are LOW,

independent of the other inputs. Information meeting the setup

and hold time requirements of the D inputs is transferred to the

Q outputs on the LOW-to-HIGH transition of the clock input.

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

VIH

Input HIGH Voltage

2.0

V

Guaranteed Input HIGH Voltage for

All Inputs

VIL

Input LOW Voltage

54

0.7

V

Guaranteed Input LOW Voltage for

All Inputs

VIL

Input LOW Voltage

74

0.8

V

Guaranteed Input LOW Voltage for

All Inputs

VIK

Input Clamp Diode Voltage

– 0.65

– 1.5

V

VCC = MIN, IIN = – 18 mA

VOH

Output HIGH Voltage

54

2.5

3.5

V

VCC = MIN, IOH = MAX, VIN = VIH

or VIL per Truth Table

VOH

Output HIGH Voltage

74

2.7

3.5

V

VCC = MIN, IOH = MAX, VIN = VIH

or VIL per Truth Table

VOL

Output LOW Voltage

54, 74

0.25

0.4

V

IOL = 4.0 mA

VCC = VCC MIN,

VIN = VIL or VIH

per Truth Table

VOL

Output LOW Voltage

74

0.35

0.5

V

IOL = 8.0 mA

VIN = VIL or VIH

per Truth Table

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

– 0.4

mA

VCC = MAX, VIN = 0.4 V

IOS

Short Circuit Current (Note 1)

– 20

– 100

mA

VCC = MAX

ICC

Power Supply Current

27

mA

VCC = MAX

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

Symbol

Parameter

Limits

Unit

Test Conditions

Symbol

Parameter

Min

Typ

Max

Unit

Test Conditions

fMAX

Maximum Input Clock Frequency

30

40

MHz

Figure 1

tPHL

Propagation Delay, MR to Q Output

18

27

ns

Figure 2

tPLH

tPHL

Propagation Delay, Clock to Output

17

18

27

27

ns

Figure 1