SN74LS669J ONSEMI [ON Semiconductor], SN74LS669J Datasheet

SN74LS669J

Manufacturer Part Number

SN74LS669J

Description

SYNCHRONOUS 4-BIT UP/DOWN COUNTER

Manufacturer

ONSEMI [ON Semiconductor]

Datasheet

1.SN74LS669J.pdf (4 pages)

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SN74LS669

SYNCHRONOUS 4-BIT

UP/DOWN COUNTER

LS669 is a 4-bit binary counter. For high speed counting applications,

this presettable counter features an internal carry lookahead for

cascading purposes. By clocking all flip-flops simultaneously so the

outputs change coincident with each other (when instructed to do so by

the count enable inputs and internal gating) synchronous operation is

provided. This helps to eliminate output counting spikes, normally

associated with asynchronous (ripple-clock) counters. The four

master-slave flip-flops are triggered on the rising (positive-going)

edge of the clock waveform by a buffered clock input.

output of the cascaded counters. Because loading is synchronous,

disabling of the counter by setting up a low level on the load input will

cause the outputs to agree with the data inputs after the next clock

pulse.

by the carry look-ahead circuitry, without additional gating. Two

count-enable inputs and a carry output help accomplish this function.

Count-enable inputs (P and T) must both be low to count. The level of

the up-down input determines the direction of the count. When the

input level is low, the counter counts down, and when the input is high,

the count is up. Input T is fed forward to enable the carry output. The

carry output will now produce a low level output pulse with a duration

9 equal to the high portion of the Q

when counting down 9 equal to the low portion of the Q

low level carry pulse may be utilized to enable successive cascaded

stages. Regardless of the level of the clock input, transitions at the P or

T inputs are allowed. By diode-clamping all inputs, transmission line

effects are minimized which allows simplification of system design.

UP/DOWN) will have no effect on the operating mode until clocking

occurs because of the fully independant clock circuits. Whether

enabled, disabled, loading or counting, the function of the counter is

dictated entirely by the conditions meeting the stable setup and hold

times.

•

July, 2006 − Rev. 6

The SN54/74LS669 is a synchronous 4-bit up/down counter. The

Circuitry of the load inputs allows loading with the carry-enable

Cascading counters for N-bit synchronous applications are provided

Any changes at control inputs (ENABLE P, ENABLE T, LOAD,

Programmable Look-Ahead Up/Down Binary/Decade Counters

Fully Synchronous Operation for Counting and Programming

Internal Look-Ahead for Fast Counting

Carry Output for n-Bit Cascading

Fully Independent Clock Circuit

Buffered Outputs

output when counting up and

output. This

LOW POWER SCHOTTKY

SYNCHRONOUS 4-BIT

ORDERING INFORMATION

UP/DOWN COUNTER

SN54LSXXXJ

SN74LSXXXN

SN74LSXXXD

http://onsemi.com

Publication Order Number:

Ceramic

Plastic

SOIC

CASE 751B-03

CASE 620-09

CASE 648-08

CERAMIC

N SUFFIX

D SUFFIX

J SUFFIX

PLASTIC

SOIC

SN74LS669/D

Related parts for SN74LS669J

SN74LS669J Summary of contents

Page 1

SN74LS669 SYNCHRONOUS 4-BIT UP/DOWN COUNTER The SN54/74LS669 is a synchronous 4-bit up/down counter. The LS669 is a 4-bit binary counter. For high speed counting applications, this presettable counter features an internal carry lookahead for cascading purposes. By clocking all flip-flops ...

Page 2

CONNECTION DIAGRAM (TOP VIEW) OUTPUTS RIPPLE CARRY ENABLE OUTPUT RIPPLE ENABLE CARRY T OUTPUT ...

Page 3

DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE Symbol Parameter V Input HIGH Voltage IH V Input LOW Voltage IL V Input Clamp Diode Voltage IK V Output HIGH Voltage OH V Output LOW Voltage OL I Input HIGH Current IH I ...

Page 4

CLOCK 1.3 V INPUT LOAD 1.3 V INPUT DATA INPUTS 1.3 V A,B,C, and D ENABLE P or ENABLE T UP/DOWN INPUT ENABLE T 1.3 V INPUT t PHL RIPPLE CARRY OUTPUT ON Semiconductor and are registered trademarks ...

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