Data

DM5490 DM7490A DM7493A
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 90A and divideby-eight for the 93A
All of these counters have a gated zero reset and the 90A
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 90A 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
90A
145 mW
93A
130 mW
Count frequency 42 MHz

Connection Diagrams
Dual-In-Line Package

TL F 6533 – 1

Order Number DM5490J DM5490W or DM7490AN
See NS Package Number J14A N14A or W14B
Dual-In-Line Package

TL F 6533 – 2

OrderNumber DM7493AN
See NS Package Number N14A

C1995 National Semiconductor Corporation

TL F 6533

RRD-B30M105 Printed in U S A

DM5490 DM7490A DM7493A
Decade and Binary Counters

July 1992

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 limitsThe
parametric values defined in the ‘‘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
SupplyVoltage
7V
Input Voltage
5 5V
Operating Free Air Temperature Range
b 55 C to a 125 C
DM54
DM74
0 C to a 70 C
Storage Temperature Range

b 65 C to a 150 C

Recommended Operating Conditions
Symbol

DM5490

Parameter

DM7490A

Units

Min
Supply Voltage

VIH

High Level Input Voltage

VIL

Clock Frequency
(Note 5)

A

tW

Pulse Width
(Note 5)

Max

5

554 75

5

5 25

Low Level Output Current

fCLK

Nom

High Level Output Current

IOL

Min

Low Level Input Voltage

IOH

Max

45

VCC

Nom

2

V

2

V

08

08

V

b0 8

b0 8

mA

16
0

32

B

0

16

A

15

16
0

32

0

mA

16

MHz

15

B

30

30

Reset

15

15

tREL

Reset Release Time (Note 5)

TAFree Air Operating Temperature

25

ns

25

b 55

125

ns

0

70

C

’90A Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol

Parameter

Conditions

VI

Input Clamp Voltage

VOH

High Level Output
Voltage

VOL

Low Level Output
Voltage

II

Input Current
Input Voltage

IIH

High LevelInput
Current

Max

Min

VCC e Min II e b12 mA
VCC e Min IOH e Max
VIL e Max VIH e Min
VCC e Min IOL e Max
VIH e Min VIL e Max (Note 4)

Typ
(Note 1)

24

Units
V

34
02

V
04

V

1

VCC e Max VI e 5 5V

mA

ICC

VCC e Max
VI e 0 4V

80
40
120

Short Circuit
Output Current

VCC e Max
(Note 2)

Supply Current

A

VCC e Max (Note 3)

b1 6

mAb3 2

Reset
B

IOS

Low Level Input
Current

A
Reset
B

IIL

VCC e Max
VI e 2 7V

Max
b1 5

b4 8

DM54

b 20

b 57

DM74

b 18

mA

b 57

29

42

mA
mA

Note 1 All typicals are at VCC e 5V TA e 25 C
Note 2 Not more than one output should be shorted at a time
Note 3 ICC is measured with all outputs open both RO inputs grounded following momentary...