Philips Semiconductors

Product specification

74F1244

Octal buffer (3-State)

2

1989 Apr 04

853–0041 96221

FEATURES

(20

µA in High and Low states)

microprocessors

DESCRIPTION

The 74F1244 is an octal buffer that is ideal for driving bus lines or

buffer memory address registers. The outputs are capable of sinking

64mA and sourcing up to 15mA, producing very good capacitive

drive characteristics. The device features two Output Enables, OEa

and OEb, each controlling four of the 3-State outputs.

The 74F1244 is pin and functionally compatible with the 74F244.

The lower power and light bus loading features make it an ideal part

to interface directly with MOS microprocessors.

PIN CONFIGURATION

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20 VCC

OEa

Ia0

Yb0

Ia1

Yb1

Ia2

Yb2

Ia3

Yb3

GND

SF00227

OEb

Ya0

Ib0

Ya1

Ib1

Ya2

Ib2

Ya3

Ib3

TYPE

TYPICAL

PROPAGATION

DELAY

TYPICAL SUPPLY

CURRENT (TOTAL)

74F1244

4.5ns

43mA

ORDERING INFORMATION

DESCRIPTION

COMMERCIAL RANGE

DRAWING

NUMBER

20-pin plastic DIP

N74F1244N

SOT146-1

20-pin plastic SOL

N74F1244D

SOT163-1

INPUT AND OUTPUT LOADING AND FAN OUT TABLE

PINS

DESCRIPTION

74F (U.L.)

HIGH/LOW

LOAD VALUE

HIGH/LOW

Ian, Ibn

Data inputs

1.0/0.033

20

µA/20µA

OEa, OEb

Output enable inputs (active Low)

1.0/0.033

20

µA/20µA

Yan, Ybn

Data outputs

750/106.7

15mA/64mA

NOTE: One (1.0) FAST unit load is defined as: 20

µA in the high state and 0.6mA in the low state.

LOGIC SYMBOL

OEa

1

SF00228

2

4

6

8

17

15

13

11

18

16

14

12

3

5

7

9

Ia0

Ia1

Ia2

Ia3

Ib0

Ib1

Ib2

Ib3

Ya0

Ya1 Ya2

Ya3 Yb0 Yb1 Yb2 Yb3

VCC = Pin 20

GND = Pin 10

OEb

19

IEC/IEEE SYMBOL

2

1

EN1

1

2

SF01366

19

4

6

8

17

15

13

11

EN2

9

7

5

3

12

14

16

18