CY74FCT191T

4-BIT UP/DOWN BINARY COUNTER

SCCS016A – MAY 1994 – REVISED SEPTEMBER 2001

2

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

ORDERING INFORMATION

TA

PACKAGE†

SPEED

(ns)

ORDERABLE

PART NUMBER

TOP-SIDE

MARKING

QSOP – Q

Tape and reel

6.2

CY74FCT191CTQCT

FT191-3

SOIC

SO

Tube

6.2

CY74FCT191CTSOC

FCT191C

–40

°C to 85°C

SOIC – SO

Tape and reel

6.2

CY74FCT191CTSOCT

FCT191C

SOIC

SO

Tube

7.8

CY74FCT191ATSOC

FCT191A

SOIC – SO

Tape and reel

7.8

CY74FCT191ATSOCT

FCT191A

† Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are

available at www.ti.com/sc/package.

Function Tables

RC FUNCTION

INPUTS

OUTPUTS

CE

CP

TC†

RC

L

H

H

X

X

H

X

X

L

H

H = High logic level, L = Low logic level,

X = Don’t care,

= Low pulse

† TC is generated internally.

MODE SELECT

INPUTS

MODE

PL

CE

U/D

CP

MODE

H

L

L

↑

Count up

H

L

H

↑

Count down

L

X

X

X

Preset (asynchronous)

H

H

X

X

No change (hold)

H = High logic level, L = Low logic level, X = Don’t care,

↑ = Low-to-high clock transition