SN74F193A

SYNCHRONOUS 4-BIT UP/DOWN BINARY COUNTER

WITH DUAL CLOCK AND CLEAR

SDFS031A – D3693, JANUARY 1991 – REVISED OCTOBER 1993

Copyright

2–1

POST OFFICE BOX 655303

Count Lengths

Cascaded Counters

Small-Outline Packages and Standard

Plastic 300-mil DIPs

description

The SN74F193A is a synchronous, 4-bit binary up/down counter. 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 either count /clock (UP or

DOWN) input. The direction of the count is determined by which count input is pulsed while the other count input

is high.

All four counters are fully programmable; that is, each output may be preset to either level by placing a low on

the LOAD input and entering the desired data at the data (D) inputs. The output will change to agree with the

data inputs independently of the count pulses. This feature allows the counters to be used as modulo-N dividers

by simply modifying the count length with the preset inputs.

A high level applied to the clear (CLR) input forces all outputs to the low level. The clear function is independent

of the count and load inputs.

These counters were designed to be cascaded without the need for external circuitry. The borrow (BO) output

produces a low-level pulse while the count is zero (all Q outputs low) and the DOWN input is low. Similarily, the

carry (CO) output produces a low-level pulse while the count is 15 (all Q outputs high) and the UP input is low.

The counters can then be easily cascaded by feeding the borrow and carry outputs to the count-down and

count-up inputs, respectively, of the succeeding counter.

The SN74F193A is characterized for operation from 0

°C to 70°C.

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

B

DOWN

UP

GND

A

CLR

BO

CO

LOAD

C

D

D OR N PACKAGE

(TOP VIEW)

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.