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DM7490AN

Part # DM7490AN
Description IC COUNTER BINARY/DECADE 14-DIP
Category IC
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National Semiconductor Corp
Date Code: 8348
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Technical Document


DISCLAIMER: The information provided herein is solely for informational purposes. Customers must be aware of the suitability of this product for their application, and consider that variable factors such as Manufacturer, Product Category, Date Codes, Pictures and Descriptions may differ from available inventory.

© 2000 Fairchild Semiconductor Corporation DS006533 www.fairchildsemi.com
August 1986
Revised March 2000
DM7490A Decade and Binary Counters
DM7490A
Decade and Binary Counters
General Description
The DM7490A monolithic counter contains four master-
slave flip-flops and additional gating to provide a divide-by-
two counter and a three-stage binary counter for which the
count cycle length is divide-by-five.
The counter has a gated zero reset and also has gated set-
to-nine inputs for use in BCD nine’s complement applica-
tions.
To use the maximum count length (decade or four-bit
binary), the B input is connected to the Q
A
output. The
input count pulses are applied to input A and the outputs
are as described in the appropriate Function Table. A sym-
metrical divide-by-ten count can be obtained from the
counters by connecting the Q
D
output to the A input and
applying the input count to the B input which gives a divide-
by-ten square wave at output Q
A
.
Features
Typical power dissipation
145 mW
Count frequency 42 MHz
Ordering Code:
Connection Diagram
Order Number Package Number Package Description
DM7490AN N14A 14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
www.fairchildsemi.com 2
DM7490A
Function Tables
BCD Count Sequence (Note 1)
BCD Bi-Quinary (5-2) (Note 2)
Reset/Count Function Table
H = HIGH Level
L = LOW Level
X = Don’t Care
Note 1: Output QA is connected to input B for BCD count.
Note 2: Output QD is connected to input A for bi-quinary count
Logic Diagram
The J and K inputs shown without connection are for reference only and
are functionally at a HIGH level.
Count Outputs
Q
D
Q
C
Q
B
Q
A
0 LLLL
1LLLH
2LLHL
3LLHH
4LHLL
5LHLH
6LHHL
7LHHH
8 HLLL
9HLLH
Count Outputs
Q
A
Q
D
Q
C
Q
B
0 LLLL
1LLLH
2LLHL
3LLHH
4LHLL
5 HLLL
6HLLH
7HLHL
8HLHH
9HHLL
Reset Inputs Outputs
R0(1) R0(2) R9(1) R9(2) Q
D
Q
C
Q
B
Q
A
H H L X LLLL
H H X L LLLL
XXHHHLLH
X L X L COUNT
L X L X COUNT
L X X L COUNT
X L L X COUNT
3 www.fairchildsemi.com
DM7490A
Absolute Maximum Ratings(Note 3)
Note 3: 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 in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Note 4: T
A
= 25°C and V
CC
= 5V.
DC Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Note 5: All typicals are at V
CC
= 5V, T
A
= 25°C.
Note 6: Q
A
outputs are tested at I
OL
= Max plus the limit value of I
IL
for the B input. This permits driving the B input while maintaining full fan-out capability.
Note 7: Not more than one output should be shorted at a time.
Note 8: I
CC
is measured with all outputs open, both RO inputs grounded following momentary connection to 4.5V, and all other inputs grounded.
Supply Voltage 7V
Input Voltage 5.5V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range 65°C to +150°C
Symbol Parameter Min Nom Max Units
V
CC
Supply Voltage 4.75 5 5.25 V
V
IH
HIGH Level Input Voltage 2 V
V
IL
LOW Level Input Voltage 0.8 V
I
OH
HIGH Level Output Current 0.8 mA
I
OL
LOW Level Output Current 16 mA
f
CLK
Clock Frequency A 0 32
MHz
(Note 4) B 0 16
t
W
Pulse Width A 15
(Note 4) B 30 ns
Reset 15
t
REL
Reset Release Time (Note 4) 25 ns
T
A
Free Air Operating Temperature 0 70 °C
Symbol Parameter Conditions Min
Typ
Max Units
(Note 5)
V
I
Input Clamp Voltage V
CC
= Min, I
I
= 12 mA 1.5 V
V
OH
HIGH Level V
CC
= Min, I
OH
= Max
2.4 3.4 V
Output Voltage V
IL
= Max, V
IH
= Min
V
OL
LOW Level V
CC
= Min, I
OL
= Max
0.2 0.4 V
Output Voltage V
IH
= Min, V
IL
= Max (Note 6)
I
I
Input Current @ Max Input Voltage V
CC
= Max, V
I
= 5.5V 1 mA
I
IH
HIGH Level V
CC
= Max A 80
Input Current V
I
= 2.7V Reset 40 µA
B 120
I
IL
LOW Level V
CC
= Max A 3.2
Input Current V
I
= 0.4V Reset 1.6 mA
B 4.8
I
OS
Short Circuit Output Current V
CC
= Max (Note 7) 18 57 mA
I
CC
Supply Current V
CC
= Max (Note 8) 29 42 mA
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