TL F 10684
CGS74C2525
CGS74CT2525
CGS74C2526
CGS74CT2526
1-to-8
Minimum
Skew
Clock
Driver
September 1995
CGS74C2525
CGS74CT2525
CGS74C2526
CGS74CT2526
1-to-8 Minimum Skew Clock Driver
The CGS 'C CT2525 is a minimum skew clock driver with
one input driving eight outputs specifically designed for sig-
nal generation and clock distribution applications The '2525
is designed to distribute a single clock to eight separate
receivers with low skew across all outputs during both the
t
PLH
and t
PHL
transitions The '2526 is similar to the '2525
but contains a multiplexed clock input to allow for systems
with dual clock speeds or systems where a separate test
clock has been implemented
Features
Y
These CGS devices implement National's FACT
TM
family
Y
Ideal for signal generation and clock distribution
Y
Guaranteed pin to pin and part to part skew
Y
Multiplexed clock input ('2526)
Y
Guaranteed 2 kV minimum ESD protection
Y
Symmetric output current drive of 24 mA for I
OL
I
OH
Y
'CT has TTL-compatible inputs
Y
These products are identical to 74AC ACT2525 and
2526
Y
Available as Mil Aero versions
54AC ACT2525
54AC ACT2526
Logic Symbols
'2525
TL F 10684 1
'2526
TL F 10684 2
Connection Diagrams
Pin Assignment
for DIP and SOIC
'2525
TL F 10684 3
'2526
TL F 10684 4
TRI-STATE
is a registered trademark of National Semiconductor Corporation
FACT
TM
is a trademark of National Semiconductor Corporation
C1996 National Semiconductor Corporation
RRD-B30M106 Printed in U S A
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Functional Description
On the multiplexed clock device the SEL pin is used to
determine which CLKn input will have an active effect on
the outputs of the circuit When SEL
e
1 the CLK1 input is
selected and when SEL
e
0 the CLK0 input is selected
The non-selected CLKn input will not have any effect on the
logical output level of the circuit The output pins act as a
single entity and will follow the state of the CLK or
CLK1 CLK0 pins when either the multiplexed ('2526) or the
straight ('2525) clock distribution chip is selected
Pin Description
Pin Names
Description
CLK
Clock Input ('2525)
CLK0 CLK1
Clock Inputs ('2526)
O
0
O
7
Outputs
SEL
Clock Select ('2526)
Truth Tables
'2525
Inputs
Outputs
CLK
O
0
O
7
L
L
H
H
'2526
Inputs
Outputs
CLK0
CLK1
SEL
O
0
O
7
L
X
L
L
H
X
L
H
X
L
H
L
X
H
H
H
L
e
Low Voltage Level
H
e
High Voltage Level
X
e
Immaterial
'2525
TL F 10684 7
'2526
TL F 10684 8
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2
Absolute Maximum Ratings
(Note 1)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Supply Voltage (V
CC
)
b
0 5V to
a
7 0V
DC Input Diode Current (I
IK
)
V
I
e b
0 5V
b
20 mA
V
I
e
V
CC
a
0 5V
a
0 2 mA
DC Input Voltage (V
I
)
b
0 5V to (V
CC
a
0 5V)
DC Output Diode Current (I
OK
)
V
O
e
0 5V
b
20 mA
V
O
e
V
CC
a
0 5V
a
20 mA
DC Output Voltage (V
O
)
b
0 5V to (V
CC
a
0 5V)
DC Output Source
or Sink Current (I
O
)
g
50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)
g
50 MA
Storage Temperature (T
STG
)
b
65 C to
a
150 C
Junction Temperature (i
JA
)
Plastic (N) 14-Lead
102 C W
Plastic (M) 14-Lead
128 C W
Plastic (N) 16-Lead
97 C W
Plastic (M) 16-Lead
124 C W
Recommended Operating
Conditions
Supply Voltage (V
CC
)
`C'
2 0V to 6 0V
`CT'
4 5V to 5 5V
Input Voltage (V
I
)
0V to V
CC
Output Voltage (V
O
)
0V to V
CC
Operating Temperature (T
A
)
CGS74C CT
b
40 C to
a
85 C
54AC ACT
b
55 C to
a
125 C
Input Rise and Fall Times Devices
(30% to 70% of V
CC
)
V
CC
e
3 3V
10 5 ns max
4 5V
14 4 ns max
5 5V
17 6 ns max
Input Rise and Fall Times Devices
(0 8V to 2 0V)
9 6 ns max
Note 1
Absolute maximum ratings are those values beyond which damage
to the device may occur The databook specifications should be met without
exception to ensure that the system design is reliable over its power supply
temperature and output input loading variables National does not recom-
mend operation of CGS circuits outside databook specifications
DC Electrical Characteristics for CGS74C and 54AC Family Devices
Over recommended operating conditions unless specified otherwise
CGS74C
54AC
CGS74C
Symbol
Parameter
V
CC
T
A
e a
25 C
T
A
e
T
A
e
Units
Conditions
(V)
b
55 C to
a
125 C
b
40 C to
a
85 C
Typ
Guaranteed Limits
V
IH
Minimum High Level
3 0
1 5
2 1
2 1
2 1
V
OUT
e
0 1V
Input Voltage
4 5
2 25
3 15
3 15
3 15
V
or V
CC
b
0 1V
5 5
2 75
3 85
3 85
3 85
V
IL
Maximum Low Level
3 0
1 5
0 9
0 9
0 9
V
OUT
e
0 1V
Input Voltage
4 5
2 25
1 35
1 35
1 35
V
or V
CC
b
0 1V
5 5
2 75
1 65
1 65
1 65
V
OH
Minimum High Level
3 0
2 99
2 9
2 9
2 9
I
OUT
e b
50 mA
Output Voltage
4 5
4 49
4 4
4 4
4 4
V
(Note 2)
5 5
5 49
5 4
5 4
5 4
V
IN
e
V
IL
or V
IH
3 0
2 56
2 4
2 46
b
12 mA
4 5
3 86
3 7
3 76
V
I
OH
b
24 mA
5 5
4 86
4 7
4 76
b
24 mA
V
OL
Maximum Low Level
3 0
0 002
0 1
0 1
0 1
I
OUT
e
50 mA
Output Voltage
4 5
0 001
0 1
0 1
0 1
V
(Note 2)
5 5
0 001
0 1
0 1
0 1
V
IN
e
V
IL
or V
IH
3 0
0 36
0 40
0 44
12 mA
4 5
0 36
0 50
0 44
V
I
OL
24 mA
5 5
0 36
0 50
0 44
24 mA
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DC Electrical Characteristics for CGS74C and 54AC Family Devices
(Continued)
Over recommended operating conditions unless specified otherwise
CGS74C
54AC
CGS74C
Symbol
Parameter
V
CC
T
A
e a
25 C
T
A
e
T
A
e
Units
Conditions
(V)
b
55 C to
a
125 C
b
40 C to
a
85 C
Typ
Guaranteed Limits
I
IN
Maximum Input
5 5
g
0 1
g
1 0
g
1 0
m
A
Leakage Current
V
I
e
V
CC
GND
(Note 3)
I
OLD
Minimum Dynamic
5 5
50
75
mA
V
OLD
e
1 65V Max
I
OHD
Output Current
5 5
b
50
b
75
mA
V
OHD
e
3 85V Min
(Note 4)
I
CC
Maximum Quiescent
5 5
8 0
80 0
80 0
m
A
V
IN
e
V
CC
Supply Current
or GND
(Note 3)
DC Electrical Characteristics for CGS74CT and 54ACT Family Devices
Over recommended operating conditions unless specified otherwise
CGS74CT
54ACT
CGS74CT
Symbol
Parameter
V
CC
T
A
e a
25 C
T
A
e
T
A
e
Units
Conditions
(V)
b
55 C to
a
125 C
b
40 C to
a
85 C
Typ
Guaranteed Limits
V
IH
Minimum High Level
4 5
1 5
2 0
2 0
2 0
V
V
OUT
e
0 1V
Input Voltage
5 5
1 5
2 0
2 0
2 0
or V
CC
b
0 1V
V
IL
Maximum Low Level
4 5
1 5
0 8
0 8
0 8
V
V
OUT
e
0 1V
Input Voltage
5 5
1 5
0 8
0 8
0 8
or V
CC
b
0 1V
V
OH
Minimum High Level
4 5
4 49
4 4
4 4
4 4
V
I
OUT
e b
50 mA
Output Voltage
5 5
5 49
5 4
5 4
5 4
(Note 2)
V
IN
e
V
IL
or V
IH
4 5
3 86
3 70
3 76
V
I
OH
b
24 mA
5 5
4 86
4 70
4 76
b
24 mA
V
OL
Maximum Low Level
4 5
0 001
0 1
0 1
0 1
V
I
OUT
e
50 mA
Output Voltage
5 5
0 001
0 1
0 1
0 1
(Note 2)
V
IN
e
V
IL
or V
IH
4 5
0 36
0 50
0 44
V
I
OL
24 mA
5 5
0 36
0 50
0 44
24 mA
I
IN
Maximum Input
5 5
g
0 1
g
1 0
g
1 0
m
A
V
I
e
V
CC
GND
Leakage Current
I
CCT
Maximum I
CC
Input
5 5
0 6
1 6
1 5
mA
V
I
e
V
CC
b
2 1V
I
OLD
Minimum Dynamic
5 5
50
75
mA
V
OLD
e
1 65V Max
I
OHD
Output Current
5 5
b
50
b
75
mA
V
OHD
e
3 85V Min
(Note 4)
I
CC
Maximum Quiescent
5 5
8 0
160 0
80 0
m
A
V
IN
e
V
CC
Supply Current
or GND
(Note 5)
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AC Electrical Characteristics
Over recommended operating conditions unless specified otherwise
(Note 6)
Range
V
CC
(V)
CGS74C
54AC
CGS74C
T
A
e a
25 C
T
A
e b
55 C
T
A
e b
40 C
Symbol
Parameter
C
L
e
50 pF
to
a
125 C
to
a
85 C
Units
C
L
e
50 pF
C
L
e
50 pF
Min
Typ
Max
Min
Max
Min
Typ
Max
t
PLH
Propagation Delay
3 3
3 0
6 5
11 0
3 0
11 0
3 0
12 5
ns
t
PHL
CLK to O
n
('2525)
5 0
3 2
5 0
7 8
2 5
8 2
2 9
8 1
t
PLH
Propagation Delay
3 3
3 0
7 0
13 0
3 0
14 0
ns
t
PHL
CLKn to O
n
('2526)
5 0
3 6
5 5
7 8
3 3
8 6
t
PLH
Propagation Delay
3 3
3 0
8 0
14 0
3 0
15 0
ns
t
PHL
SEL to O
n
('2526)
5 0
4 0
6 5
8 5
3 5
9 5
t
OSHL
Maximum Skew
3 3
0 3
1 5
600
Common Edge
ps
Output-to-Output (Note 7)
5 0
0 2
1 0
500
Variation
t
OSLH
Maximum Skew
3 3
0 3
1 5
600
Common Edge
ps
Output-to-Output (Note 7)
5 0
0 2
1 0
500
Variation
t
OST
Maximum Skew
1 5
Opposite Edge
5 0
0 4
1 0
1 0
ns
Output-to-Output (Note 7)
1 0
Variation
t
PV
Maximum Skew
'C2525
Part-to-Part
'CT2525
5 0
3 5
4 0
ns
Variation (Note 8)
'C2526
'CT2526
5 0
5 0
ns
t
rise
Maximum
t
fall
Rise Fall Time
5 0
3 0
4 0
3 75
ns
(20% to 80% V
CC
)
t
rise
Maximum
t
fall
Rise Fall Time
0 9
1 1
ns
(0 8V 2 0V and 2 0V 0 8V)
AC Electrical Characteristics
Over recommended operating conditions unless specified otherwise
(Note 6)
Range
V
CC
(V)
CGS74CT
54ACT
CGS74CT
T
A
e a
25 C
T
A
e b
55 C
T
A
e b
40 C
Symbol
Parameter
C
L
e
50 pF
to
a
125 C
to
a
85 C
Units
C
L
e
50 pF
C
L
e
50 pF
Min
Typ
Max
Min
Max
Min
Max
t
PLH
Propagation Delay
5 0
4 6
6 5
9 0
4 0
10 1
ns
t
PHL
CLK to O
n
('2525)
t
PLH
Propagation Delay
5 0
5 8
8 5
11 1
5 1
12 4
ns
t
PHL
CLKn to O
n
('2526)
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