74ACT11191

SYNCHRONOUS 4BIT UP/DOWN BINARY COUNTER

SCAS106A − D3455, FEBRUARY 1990 − REVISED APRIL 1993

POST OFFICE BOX 655303

POST OFFICE BOX 1443

Copyright

2−1

Cascaded Counters

Control

PCB Layout

Minimize High-Speed Switching Noise

CMOS) 1-

mm Process

Small-Outline Packages and Standard

Plastic 300-mil DIPs

description

The 74ACT11191 is a synchronous, 4-bit binary reversible up/down counter. A synchronous counting operation

is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other

when so instructed by the steering logic. This mode of operation eliminates the output counting spikes normally

associated with asynchronous (ripple clock) counters.

The outputs of the four flip-flops are triggered on a low-to-high-level transition of the clock input if the enable

input (CTEN) is low. A high at CTEN inhibits counting. The direction of the count is determined by the level of

the down/up (D/U) input. When D/U is low, the counter counts up and when D/U is high, it counts down.

These counters feature a fully independent clock circuit. Changes at the control inputs (CTEN and D/U) that

will modify the operating mode have no effect on the contents of the counter until clocking occurs. The function

of the counter will be dictated solely by the condition meeting the stable setup and hold times.

B

12

20

18

13

14

17

11

19

CLK

C

D

A

G1

9

8

3

2

M2 [DOWN]

M3 [UP]

1,2−/1,3+

G4

C5

6,1,4

3(CT=15)Z6

2(CT=0)Z6

CTRDIV16

RCO

MAX/MIN

10

1

5D

[1]

[2]

[4]

[8]

CTEN

LOAD

D/U

QA

QB

QC

QD

† This symbol is in accordance with ANSI/IEEE Std 91-1984

and IEC Publication 617-12.

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

RCO

GND

GND

GND

GND

MAX/MIN

D/U

CLK

A

B

C

D

CTEN

LOAD

DW OR N PACKAGE

(TOP VIEW)

EPIC is a trademark of Texas Instruments Incorporated.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.