Data
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...
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