SN54ALS646, SN54ALS648, SN54AS646

SN74ALS646A, SN74ALS648A, SN74AS646, SN74AS648

OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

SDAS039F – DECEMBER 1983 – REVISED JANUARY 1995

15

POST OFFICE BOX 655303

7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I / O ports

5.5 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0

°C to 70°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range

– 65

°C to 150°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not

implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

recommended operating conditions

SN74AS648

UNIT

MIN

NOM

MAX

UNIT

VCC

Supply voltage

4.5

5

5.5

V

VIH

High-level input voltage

2

V

VIL

Low-level input voltage

0.8

V

IOH

High-level output current

–15

mA

IOL

Low-level output current

48

mA

fclock

Clock frequency

0

90

MHz

t

Pulse duration

CLKBA or CLKAB high

5

ns

tw

Pulse duration

CLKBA or CLKAB low

6

ns

tsu

Setup time, A before CLKAB

↑ or B before CLKBA↑

6

ns

th

Hold time, A after CLKAB

↑ or B before CLKBA

0

ns

TA

Operating free-air temperature

0

70

°C

electrical characteristics over recommended operating free-air temperature range (unless

otherwise noted)

PARAMETER

TEST CONDITIONS

SN74AS648

UNIT

PARAMETER

TEST CONDITIONS

MIN

TYP‡

MAX

UNIT

VIK

VCC = 4.5 V,

II = – 18 mA

– 1.2

V

VCC = 4.5 V to 5.5 V,

IOH = – 2 mA

VCC –2

VOH

VCC =4 5V

IOH = – 3 mA

2.4

3.2

V

VCC = 4.5 V

IOH = – 15 mA

2

VOL

VCC = 4.5 V,

IOL = 48 mA

0.35

0.5

V

II

Control inputs

VCC =5 5V

VI = 7 V

0.1

mA

II

A or B ports

VCC = 5.5 V

VI = 5.5 V

0.1

mA

I

Control inputs

V5 5 V

V2 7 V

20

A

IIH

A or B ports§

VCC = 5.5 V,

VI = 2.7 V

70

µA

I

Control input

V5 5 V

V0 4 V

– 0.5

mA

IIL

A or B ports§

VCC = 5.5 V,

VI = 0.4 V

– 0.75

mA

IO¶

VCC = 5.5 V,

VO = 2.25 V

–30

–112

mA

Outputs high

110

185

ICC

VCC = 5.5 V

Outputs low

120

195

mA

Outputs disabled

120

195

‡ All typical values are at VCC = 5 V, TA = 25 °C.

§ For I/O ports, the parameters IIH and IIL include the off-state output current.

¶ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.