CY74FCT191T

4-BIT UP/DOWN BINARY COUNTER

SCCS016A – MAY 1994 – REVISED SEPTEMBER 2001

6

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

timing requirements over recommended operating free-air temperature range (unless otherwise

noted) (see Figure 1)

PARAMETER

CY74FCT191AT

CY74FCT191CT

UNIT

PARAMETER

MIN

MAX

MIN

MAX

UNIT

t

Pulse duration

CP

High or Low

4

4

ns

tw

Pulse duration

PL low

5.5

5

ns

Data before PL

↓

High or Low

4

3.5

tsu

Setup time

CE before CP

↑

Low

9

7.2

ns

U/D before CP

↑

High or Low

10

8

Data after PL

↓

High or Low

1.5

1

th

Hold time

CE after CP

↑

Low

0

0

ns

U/D after CP

↑

High or Low

0

0

trec

Recovery time

PL after CP

↑

5

4.5

ns

switching characteristics over operating free-air temperature range (see Figure 1)

PARAMETER

FROM

TO

CY74FCT191AT

CY74FCT191CT

UNIT

PARAMETER

(INPUT)

(OUTPUT)

MIN

MAX

MIN

MAX

UNIT

tPLH

CP

Q

1.5

7.8

1.5

6.2

ns

tPHL

CP

Qn

1.5

7.8

1.5

6.2

ns

tPLH

CP

TC

1.5

11.8

1.5

9.4

ns

tPHL

CP

TC

1.5

11.8

1.5

9.4

ns

tPLH

CP

RC

1.5

8.5

1.5

6.8

ns

tPHL

CP

RC

1.5

8.5

1.5

6.8

ns

tPLH

CE

RC

1.5

7.2

1.5

6

ns

tPHL

CE

RC

1.5

7.2

1.5

6

ns

tPLH

U/D

RC

1.5

13

1.5

11

ns

tPHL

U/D

RC

1.5

13

1.5

11

ns

tPLH

U/D

TC

1.5

7.2

1.5

6.1

ns

tPHL

U/D

TC

1.5

7.2

1.5

6.1

ns

tPLH

P

Q

1.5

9.1

1.5

7.7

ns

tPHL

Pn

Qn

1.5

9.1

1.5

7.7

ns

tPLH

PL

Q

2

8.5

2

7.2

ns

tPHL

PL

Qn

2

8.5

2

7.2

ns