SN74ALS994

10-BIT D-TYPE TRANSPARENT READ-BACK LATCH

SDAS237A – OCTOBER 1984 – REVISED JANUARY 1995

2–3

POST OFFICE BOX 655303

recommended operating conditions

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

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

tw

Pulse duration, LE high

10

ns

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

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

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

otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP‡

MAX

UNIT

VIK

VCC = 4.5 V,

II = – 18 mA

– 1.2

V

V

All outputs

VCC = 4.5 V to 5.5 V,

IOH = – 0.4 mA

VCC –2

V

VOH

Q

VCC = 4.5 V,

IOH = – 2.6 mA

2.4

3.2

V

D

VCC =4 5V

IOL = 4 mA

0.25

0.4

VOL

D

VCC = 4.5 V

IOL = 8 mA

0.35

0.5

V

VOL

Q

VCC =4 5V

IOL = 12 mA

0.25

0.4

V

Q

VCC = 4.5 V

IOL = 24 mA

0.35

0.5

II

OERB, LE

VCC =5 5V

VI = 7 V

0.1

mA

II

D inputs

VCC = 5.5 V

VI = 5.5 V

0.1

mA

I

OERB, LE

VCC =5 5V

VI =2 7V

20

µA

IIH

D inputs§

VCC = 5.5 V,

VI = 2.7 V

20

µA

I

OERB, LE

VCC =5 5V

VI =0 4V

– 0.1

mA

IIL

D inputs§

VCC = 5.5 V,

VI = 0.4 V

– 0.1

mA

IO¶

VCC = 5.5 V,

VO = 2.25 V

–30

–112

mA

ICC

VCC = 5.5 V,

Q outputs high

30

50

mA

ICC

CC

OERB high

Q outputs low

52

82

mA

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

§ For I/O ports (QA thru QH), 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.