SN74ALS666, SN74ALS667

8-BIT D-TYPE TRANSPARENT READ-BACK LATCHES

WITH 3-STATE OUTPUTS

SDAS227A – JUNE 1984 – REVISED JANUARY 1995

4

POST OFFICE BOX 655303

timing diagram

Input Data

tdis

th

tsu†

Read Back

Data Bus

LE

Q

OERB

Input Data

tpd

tsu

tpd

CLR = H, PRE = H, OE1 = L, OE2 = L.

† This setup time ensures the read-back circuit does not create a conflict on the input data bus.

7 V

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

7 V

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

Voltage applied to D inputs and to disabled 3-state outputs

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

SN74ALS666

SN74ALS667

UNIT

MIN

NOM

MAX

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

Q

– 2.6

mA

IOH

High-level output current

D

– 0.4

mA

IOL

Low level output current

Q

24

mA

IOL

Low-level output current

D

8

mA

LE high

10

tw

Pulse duration

CLR low

10

ns

PRE low

10

t

Setup time

Data before LE

↓

10

ns

tsu

Setup time

Data before OERB

↓

10

ns

th

Hold time, data after LE

↓

5

ns

TA

Operating free-air temperature

0

70

°C