Philips Semiconductors

Product specification

74LVC821A

10-bit D-type flip-flop with 5-volt tolerant

inputs/outputs; positive-edge trigger (3-State)

1998 Sep 25

3

PIN DESCRIPTION

PIN NUMBER

SYMBOL

NAME AND FUNCTION

1

OE

Output enable input

(active LOW)

2, 3, 4, 5, 6,

7, 8, 9, 10, 11

Data inputs

23, 22, 21, 20,

19, 18, 17, 16,

15, 14

3-State flip-flop outputs

12

GND

Ground (0 V)

13

CP

Clock input (LOW-to-HIGH,

edge-triggered)

24

Positive supply voltage

FUNCTION TABLE

OPERATING MODES

INPUTS

INTERNAL FLIP FLOPS

OUTPUTS

OPERATING MODES

OE

CP

INTERNAL FLIP-FLOPS

Load and read register

L

L

↑

↑

l

h

L

H

L

H

Load register and disable outputs

H

H

↑

↑

l

h

L

H

Z

Z

Hold

L

H or L

X

NC

NC

H = HIGH voltage level

h

= HIGH voltage level one set-up time prior to the LOW-to-HIGH

CP transition

L

= LOW voltage level

l

= LOW voltage level one set-up time prior to the LOW-to-HIGH

CP transition

Z = high impedance OFF-state

↑ = LOW–to–HIGH clock transition

NC= no change

PIN CONFIGURATION

GND

Q9

CP

1

2

3

4

5

6

7

8

9

10

11

12

20

21

22

23

24

19

18

17

16

15

14

13

OE

SA00413

LOGIC SYMBOL

CP

13

Q 7

Q 8

Q 9

2

D 0

Q 0

19

20

21

22

23

9

10

11

D 7

D 8

D 9

8

D 6

Q 6

7

D 5

Q 5

14

6

D 4

Q 4

15

5

D 3

Q 3

16

4

D 2

Q 2

17

3

D 1

Q 1

18

1

OE

SA00414