Coneccion 74 90

DM74LS90 DM74LS93
Decade and Binary Counters
General Description
Each of these monolithic counters contains four masterslave flip-flops and additional gating to provide a divide-bytwo counter and a three-stage binary counter for which the
count cycle length is divide-by-five for the ’LS90 and divideby-eight for the ’LS93
All of these counters have a gated zero reset and the LS90
also hasgated set-to-nine inputs for use in BCD nine’s complement applications
To use their maximum count length (decade or four bit binary) the B input is connected to the QA output The input

count pulses are applied to input A and the outputs are as
described in the appropriate truth table A symmetrical divide-by-ten count can be obtained from the ’LS90 counters
by connecting the QD output to the Ainput and applying the
input count to the B input which gives a divide-by-ten square
wave at output QA

Features
Y
Y

Typical power dissipation 45 mW
Count frequency 42 MHz

Connection Diagrams (Dual-In-Line Packages)

TL F 6381 – 1

Order Number DM74LS90M or DM74LS90N
See NS Package Number M14A or N14A

C1995 National Semiconductor Corporation

TL F 6381

TL F 6381 – 2Order Number DM74LS93M or DM74LS93N
See NS Package Number M14A or N14A

RRD-B30M105 Printed in U S A

DM74LS90 DM74LS93 Decade and Binary Counters

June 1989

Absolute Maximum Ratings (Note)
Note The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed The device should not be operated at these limits The
parametric values defined inthe ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation

If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Supply Voltage
Input Voltage (Reset)Input Voltage (A or B)
Operating Free Air Temperature Range
DM74LS

7V
7V
5 5V
0 C to a 70 C
b 65 C to a 150 C

Storage Temperature Range

Recommended Operating Conditions
Symbol

DM74LS90

Parameter

Units

Min
Supply Voltage

VIH

High Level Input Voltage

VIL

Low Level Output Current

fCLK

Clock Frequency (Note 1)

5 25

High Level Output Current

IOL5

Low Level Input Voltage

IOH

Max

4 75

VCC

Nom

V
08

V

b0 4

mA

8

mA

tW

32

0

16

A to QA

0

20

0

10

A

Pulse Width (Note 2)

MHz

30

Reset

MHz

15

B
tW

Pulse Width (Note 1)

0

B to QB

Clock Frequency (Note 2)

A to QA
B to QB

fCLK

V

2

15

A

25

B

50

Reset

ns

25

tRELReset Release Time (Note 1)

25

tREL

Reset Release Time (Note 2)

35

TA

Free Air Operating Temperature

ns
ns

0

ns
C

70

Note 1 CL e 15 pF RL e 2 kX TA e 25 C and VCC e 5V
Note 2 CL e 50 pF RL e 2 kX TA e 25 C and VCC e 5V

’LS90 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol

ParameterConditions

VI

Input Clamp Voltage
High Level Output
Voltage

VOL

Low Level Output
Voltage

Typ
(Note 1)

VCC e Min IOH e Max
VIL e Max VIH e Min
VCC e Min IOL e Max
VIL e Max VIH e Min
(Note 4)

27

Input Current
Input Voltage

Max

Units
V

34

0 35

IOL e 4 mA VCC e Min
II

Max
b1 5

VCC e Min II e b18 mA

VOH

Min

0 25

V

05

V

04

VCC eMax VI e 7V

Reset

01

VCC e Max
VI e 5 5V

A

02

B

04

2

mA

’LS90 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted) (Continued)
Symbol
IIH

Parameter

Conditions

High Level Input
Current

VCC e Max VI e 2 7V

Min

Typ
(Note 1)

Max

Reset

20

Low Level Input
Current

A

VCC e Max...