SN54ALS640B, SN54AS640, SN74ALS640B, SN74AS640

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SDAS122A – DECEMBER 1983 – REVISED JANUARY 1995

5

POST OFFICE BOX 655303

switching characteristics (see Figure 1)

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

VCC = 4.5 V to 5.5 V,

CL = 50 pF,

R1 = 500

R2 = 500

TA = MIN to MAX†

UNIT

SN54AS640

SN74AS640

MIN

MAX

MIN

MAX

tPLH

AorB

BorA

1

8

2

7

ns

tPHL

A or B

B or A

1

7

2

6

ns

tPZH

OE

AorB

2

10

2

8

ns

tPZL

OE

A or B

2

12

2

10

ns

tPHZ

OE

AorB

2

9

2

8

ns

tPLZ

OE

A or B

2

16

2

13

ns

† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.