Fairchild DM7490A Decade and binary counter Datasheet

Revised March 2000
DM7490A
Decade and Binary Counters
General Description
Features
The DM7490A monolithic counter 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.
■ Typical power dissipation
145 mW
■ Count frequency 42 MHz
The counter has a gated zero reset and also has gated setto-nine inputs for use in BCD nine’s complement applications.
To use the 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 Function Table. A symmetrical divide-by-ten count can be obtained from the
counters by connecting the QD output to the A input and
applying the input count to the B input which gives a divideby-ten square wave at output QA.
Ordering Code:
Order Number
DM7490AN
Package Number
N14A
Package Description
14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Connection Diagram
© 2000 Fairchild Semiconductor Corporation
DS006533
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DM7490A Decade and Binary Counters
August 1986
DM7490A
Function Tables
Logic Diagram
BCD Count Sequence (Note 1)
Count
Outputs
QD
QC
QB
0
L
L
L
QA
L
1
L
L
L
H
2
L
L
H
L
3
L
L
H
H
4
L
H
L
L
5
L
H
L
H
6
L
H
H
L
7
L
H
H
H
8
H
L
L
L
9
H
L
L
H
BCD Bi-Quinary (5-2) (Note 2)
Count
Outputs
QA
QD
QC
0
L
L
L
QB
L
1
L
L
L
H
2
L
L
H
L
3
L
L
H
H
4
L
H
L
L
5
H
L
L
L
6
H
L
L
H
7
H
L
H
L
8
H
L
H
H
9
H
H
L
L
Reset/Count Function Table
Reset Inputs
R0(1)
R0(2)
H
H
Outputs
QD
QC
QB
The J and K inputs shown without connection are for reference only and
are functionally at a HIGH level.
QA
R9(1)
R9(2)
H
L
X
L
L
L
L
H
X
L
L
L
L
L
X
X
H
H
H
L
L
H
X
L
X
L
COUNT
L
X
L
X
COUNT
L
X
X
L
COUNT
X
L
L
X
COUNT
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
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Supply Voltage
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.
7V
Input Voltage
5.5V
0°C to +70°C
Operating Free Air Temperature Range
−65°C to +150°C
Storage Temperature Range
Recommended Operating Conditions
Symbol
Parameter
Min
Nom
Max
4.75
5
5.25
Units
VCC
Supply Voltage
VIH
HIGH Level Input Voltage
VIL
LOW Level Input Voltage
0.8
V
IOH
HIGH Level Output Current
−0.8
mA
IOL
LOW Level Output Current
16
mA
fCLK
Clock Frequency
A
0
32
(Note 4)
B
0
16
Pulse Width
A
15
(Note 4)
B
30
Reset
15
tW
V
2
tREL
Reset Release Time (Note 4)
25
TA
Free Air Operating Temperature
0
V
MHz
ns
ns
°C
70
Note 4: TA = 25°C and VCC = 5V.
DC Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
VI
Input Clamp Voltage
VCC = Min, II = −12 mA
VOH
HIGH Level
VCC = Min, IOH = Max
VOL
II
IIH
IIL
Min
2.4
Output Voltage
VIL = Max, VIH = Min
LOW Level
VCC = Min, IOL = Max
Output Voltage
VIH = Min, VIL = Max (Note 6)
Typ
(Note 5)
Max
Units
−1.5
V
3.4
0.2
Input Current @ Max Input Voltage VCC = Max, VI = 5.5V
V
0.4
V
1
mA
HIGH Level
VCC = Max
A
80
Input Current
VI = 2.7V
Reset
40
B
120
LOW Level
VCC = Max
A
−3.2
Input Current
VI = 0.4V
Reset
−1.6
B
−4.8
IOS
Short Circuit Output Current
VCC = Max (Note 7)
ICC
Supply Current
VCC = Max (Note 8)
−18
29
µA
mA
−57
mA
42
mA
Note 5: All typicals are at VCC = 5V, TA = 25°C.
Note 6: QA outputs are tested at IOL = Max plus the limit value of IIL 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: ICC is measured with all outputs open, both RO inputs grounded following momentary connection to 4.5V, and all other inputs grounded.
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DM7490A
Absolute Maximum Ratings(Note 3)
DM7490A
AC Switching Characteristics
at VCC = 5V and TA = 25°C
Symbol
fMAX
tPLH
Parameter
Min
Maximum Clock
A to QA
32
Frequency
B to QB
16
Propagation Delay Time
Propagation Delay Time
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time
LOW-to-HIGH Level Output
tPHL
Propagation Delay Time
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time
LOW-to-HIGH Level Output
tPHL
Propagation Delay Time
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time
LOW-to-HIGH Level Output
tPHL
Propagation Delay Time
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time
LOW-to-HIGH Level Output
tPHL
Propagation Delay Time
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time
LOW-to-HIGH Level Output
tPHL
Propagation Delay Time
HIGH-to-LOW Level Output
tPHL
RL = 400Ω, CL = 15 pF
To (Output)
LOW-to-HIGH Level Output
tPHL
From (Input)
Units
MHz
A to QA
16
ns
A to QA
18
ns
A to QD
48
ns
A to QD
50
ns
B to QB
16
ns
B to QB
21
ns
B to QC
32
ns
B to QC
35
ns
B to QD
32
ns
B to QD
35
ns
SET-9 to QA, QD
30
ns
SET-9 to QB, QC
40
ns
40
ns
Propagation Delay Time
SET-0
HIGH-to-LOW Level Output
Any Q
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Max
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DM7490A Decade and Binary Counters
Physical Dimensions inches (millimeters) unless otherwise noted
14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Package Number N14A
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
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to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
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