Fairchild DM74LS469 8-bit up/down counter Datasheet

DM74LS469
8-Bit Up/Down Counter
General Description
The ’LS469 is an 8-bit synchronous up/down counter with
parallel load and hold capability. Three function-select inputs
(LD, UD, CBI) provide one of four operations which occur
synchronously on the rising edge of the clock (CK).
The LOAD operation loads the inputs (D7–D0) into the output
register (Q7–Q0). The HOLD operation holds the previous
value regardless of clock transitions. The INCREMENT operation adds one to the output register when the carry-in input is TRUE (CBI = LOW), otherwise the operation is a
HOLD. The carry-out (CBO) is TRUE (CBO = LOW) when
the output register (Q7–Q0) is all HIGHs, otherwise FALSE
(CBO = HIGH). The DECREMENT operation subtracts one
from the output register when the borrow-in input is TRUE
(CBI = LOW), otherwise the operation is a HOLD. The
borrow-out (CBO) is TRUE (CBO = LOW) when the output
register (Q7–Q0) is all LOWs, otherwise FALSE (CBO
= HIGH).
Connection Diagram
The output register (Q7–Q0) is enabled when OE is LOW,
and disabled (HI-Z) when OE is HIGH. The output drivers will
sink the 24 mA required for many bus-interface standards.
Two or more ’LS469 octal up/down counters may be cascaded to provide larger counters.
Features/Benefits
n 8-bit up/down counter for microprogram-counter, DMA
controller and general-purpose counting applications
n 8 bits matches byte boundaries
n Bus-structured pinout
n 24-pin SKINNYDIP saves space
n 3-STATE outputs drive bus lines
n Low current PNP inputs reduce loading
n Expandable in 8-bit increments
Standard Test Load
Top View
DS008333-3
DS008333-1
Order Number DM54LS469J,
DM74LS469J or DM74LS469N
See Package Number J24F or N24C
© 1998 Fairchild Semiconductor Corporation
DS008333
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DM74LS469 8-Bit Up/Down Counter
April 1998
Function Table
OE
CK
LD
UD
CBI
D7–D0
Q7–Q0
H
X
X
X
X
X
Z
HI-Z
L
↑
L
X
X
D
D
LOAD
L
↑
H
L
H
X
Q
HOLD
L
↑
H
L
L
X
Q plus 1
INCREMENT
L
↑
H
H
H
X
Q
HOLD
L
↑
H
H
L
X
Q minus 1
DECREMENT
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Operation
2
Absolute Maximum Ratings (Note 1)
Off-State Output Voltage
Storage Temperature
7V
5.5V
Supply Voltage VCC
Input Voltage
5.5V
−65˚C to +150˚C
Operating Conditions
Symbol
Parameter
Military
Min
Typ
5
VCC
Supply Voltage
4.5
TA
Operating Free-Air Temperature
−55
tW
Width of Clock
Commercial
Min
Typ
Max
5.5
4.75
5
5.25
V
125 (Note 2)
0
75
˚C
Low
40
35
High
30
25
tSU
Set Up Time
60
th
Hold Time
0
Units
Max
10
ns
50
−15
0
ns
−15
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits.
Note 2: Case Temperature
Electrical Characteristics
Over Operating Conditions
Symbol
Parameter
VIL
Low-Level Input Voltage
VIH
High-Level Input Voltage
VIC
Input Clamp Voltage
Test Conditions
VCC = MIN
VCC = MAX
II = −18 mA
VI = 0.4V
VI = 2.4V
VI = 5.5V
IIL
Low-Level Input Current
High-Level Input Current
II
Maximum Input Current
VCC = MAX
VCC = MAX
IOL = 12 mA
Low-Level Output Voltage
VCC = MIN
VIL = 0.8V
MIL
VOL
VIH = 2V
VCC = MIN
COM
MIL
IOL = 24 mA
IOH = −2 mA
VIL = 0.8V
VIH = 2V
COM
High-Level Output Voltage
Off-State Output Current
VIL = 0.8V
VIH = 2V
IOS
Output Short-Circuit Current
(Note 3)
VCC = 5.0V
ICC
Supply Current
VCC = MAX
IOZH
Max
Units
0.8
V
−1.5
V
−0.25
mA
V
25
µA
1
mA
0.5
V
2.4
VCC = MAX
IOZL
Typ
(Note 4)
2
IIH
VOH
Min
V
IOH = −3.2 mA
VO = 0.4V
VO = 2.4V
VO = 0V
−100
−30
120
µA
100
µA
−130
mA
180
mA
Note 3: No more than one output should be shorted at a time and duration of the short-circuit should not exceed one second
Note 4: All typical values are VCC = 5V, TA = 25˚C.
3
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Switching Characteristics
Over Operating Conditions
Symbol
Parameter
Test Conditions
Military
(See Test Load/Waveforms)
fMAX
Maximum Clock
Frequency
Min
Typ
Commercial
Max
10.5
Min
Typ
Units
Max
12.5
MHz
tPD
CBI to CBO Delay
60
35
50
ns
Clock to Q
CL = 50 pF
R1 = 200Ω
35
tPD
20
35
20
30
ns
tPD
Clock to CBO
R2 = 390Ω
55
95
55
80
ns
tPZX
Output Enable Delay
20
45
20
35
ns
tPXZ
Output Disable Delay
20
45
20
35
ns
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4
Logic Diagram
LS469
DS008333-2
5
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6
Physical Dimensions
inches (millimeters) unless otherwise noted
24-Pin Narrow Ceramic Dual-In-Line Package (J)
Order Number DM54LS469J or DM74LS469J
Package Number J24F
24-Pin Narrow Plastic Dual-In-Line Package (N)
Order Number DM74LS469N
Package Number N24C
7
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DM74LS469 8-Bit Up/Down Counter
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device or system, or to affect its safety or effectiveness.
failure 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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