CY74FCT191T

4-BIT UP/DOWN BINARY COUNTER

SCCS016A – MAY 1994 – REVISED SEPTEMBER 2001

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POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

D Function, Pinout, and Drive Compatible

With FCT and F Logic

D Reduced VOH (Typically = 3.3 V) Versions

of Equivalent FCT Functions

D Edge-Rate Control Circuitry for

Significantly Improved Noise

Characteristics

D Ioff Supports Partial-Power-Down Mode

Operation

D ESD Protection Exceeds JESD 22

– 2000-V Human-Body Model (A114-A)

– 200-V Machine Model (A115-A)

– 1000-V Charged-Device Model (C101)

D Matched Rise and Fall Times

D 64-mA Output Sink Current

32-mA Output Source Current

description

The CY74FCT191T is a reversible modulo-16 binary counter, featuring synchronous counting and

asynchronous presetting. The preset allows the CY74FCT191T to be used in programmable dividers. The count

enable input, terminal count output, and ripple-clock output make possible a variety of methods of implementing

multiusage counters. In the counting modes, state changes are initiated by the rising edge of the clock.

This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs,

preventing damaging current backflow through the device when it is powered down.

PIN DESCRIPTION

NAME

DESCRIPTION

CE

Count enable input (active low)

CP

Clock pulse input (active rising edge)

P

Parallel data inputs

PL

Asynchronous parallel load input (active low)

U/D

Up/down count control input

Q

Flip-flop outputs

RC

Ripple clock output (active low)

TC

Terminal count output

Copyright

 2001, 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.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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P1

Q1

Q0

CE

U/D

Q2

Q3

GND

VCC

P0

CP

RC

TC

PL

P2

P3

Q OR SO PACKAGE

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