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CGS74LCT2524
1 to 4 Minimum Skew (300 ps) 3V Clock Driver
General Description
This minimum skew clock driver is a 3V option of the current
CGS74CT2524 MinimumSkew Clock Driver and is designed
for Clock Generation and Support (CGS) applications operating at low voltage, high frequencies. This device guarantees minimum output skew across the outputs of a given device.
Skew parameters are also provided as a means to measure
duty cycle requirements as those found in high speed clocking systems. This minimum skew clock driver with one input
driving four outputs, is specifically designed for signal generation and clock distribution applications.
Features
n Ideal for low power/low noise high speed applications
n Guaranteed:
— 300 ps pin-to-pin skew (t
OSHL
and t
OSLH
)
n Implemented on National’s FACT
™
family process
n 1 input to 4 outputs low skew clock distribution
n Symmetric output current drive: 12 mA I
OH/IOL
n Industrial temperature of −40˚C to +85˚C
n 8-pin SOIC package
n Low dynamic power consumption above 20 MHz
n Guaranteed 2 kV ESD protection
Logic Symbol
Pin Description
Pin Names Description
CLK Clock Input
O
0–O3
Outputs
Truth Table
Inputs Outputs
CLK O
0–O3
LL
HH
L
=
Low Logic Level
H=High Logic Level
Connection Diagrams
FACT™is a trademark of National Semiconductor Corporation.
DS011956-1
The output pins act as a single entity and will follow the state of the CLK
when the clock distribution chip is selected.
Pin Assignment
SOIC (MO)
DS011956-2
DS011956-3
See NS Package Number M08A
January 2000
CGS74LCT2524 1 to 4 Minimum Skew (300 ps) 3V Clock Driver
© 2000 National Semiconductor Corporation DS011956 www.national.com
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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
) −0.5V to 7.0V
DC Input Voltage Diode Current (I
IK
)
V=−0.5V −20 mA
V=V
CC
+ 0.5V +20 mA
DC Input Voltage (V
I
) −0.5V to VCC+0.5V
DC Output Diode Current (I
O
)
V=−0.5V −20 mA
V=V
CC
+ 0.5V +20 mA
DC Output Voltage (V
O
) −0.5V to VCC+0.5V
DC Output Source or Sink Current
(I
O
)
±
50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)
±
50 mA
Storage Temperature (T
STG
) −65˚C to +150˚C
Junction Temperature (θ
JA
)
Airflow 0 225 500 LFM
M 167 132 117 ˚C/W
Recommended Operating
Conditions
Supply Voltage (VCC) 3.0V to 3.6V
Input Voltage (V
IN
) 0VtoV
CC
Output Voltage (VO) 0VtoV
CC
Operating Temperature (TA)
Industrial −40˚C to +85˚C
Commercial 0˚C to +70˚C
Input Rise and Fall Times 9.6 ns max
(0.8V to 2.0V)
Note 1:
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 DC and AC Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The Recommended Operating Conditions will define the conditions for
actual device operation.
DC Electrical Characteristics
Over recommended operating conditions unless specified otherwise.
Symbol Parameter Conditions
V
CC
(V)
CGS74LCT2524
UnitsT
A
=
+25˚C
T
A
=
−40˚C to
+85˚C
Typ Guaranteed Limits
V
IH
Minimum High
Level
V
OUT
=
0.1V or V
CC
=
−0.1V
3.3 1.5 2.0 2.0 V
Input Voltage
V
IL
Maximum Low
Level
V
OUT
=
0.1V or V
CC
=
−0.1V
3.3 1.5 0.8 0.8 V
Input Voltage
V
OH
Minimum High
Level
V
IN
=
V
IL
or VIH,I
OUT
=
−50 µA 3.3 2.9 2.9 V
Output Voltage V
IN
=
V
IL
or VIH,I
OH
=
−12 mA 3.3 2.5 2.4 V
V
OL
Minimum Low Level V
IN
=
V
IL
or VIH,I
OUT
=
50 µA 3.3 0.1 0.1 V
Output Voltage V
IN
=
V
IL
or VIH,I
OL
=
−12 mA 3.3 0.3 0.4 V
I
IN
Maximum Input V
IN
=
V
CC
, GND 3.6
±
0.1
±
1.0 µA
Leakage Current
I
CCT
Maximum ICC/Input V
IN
=
2.4V 3.6 100 µA
I
OLD
Minimum Dynamic V
OLD
=
0.8V (max) 3.6 36 mA
I
OHD
Output Current V
OHD
=
2.0V (min) 3.6 −25 mA
I
CC
Maximum
Quiescent
V
IN
=
V
CC
or GND
3.6 2.5 10 µA
Supply Current
CGS74LCT2524
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AC Electrical Characteristics
Over recommended operating conditions unless specified otherwise. All typical values are measured at V
CC
=
3.3V, T
A
=
25˚C
Symbol Parameter
LCT2524
Units
V
CC
=
3.0V to 3.6V
T
A
=
−40˚C to +85˚C
C
L
=
50 pF
R
L
=
500Ω
Min Typ Max
t
PLH
Low-to-High Propagation Delay 6 15.0 ns
CLK to O
n
t
PHL
High-to-Low Propagation Delay 6 15.0 ns
CLK to O
n
Extended AC Electrical Characteristics
Over recommended operating conditions unless specified otherwise. All typical values are measured at V
CC
=
3.3V, T
A
=
25˚C
Symbol Parameter
LCT2524
Units
V
CC
=
3.0V to 3.6V
T
A
=
−40˚C to +85˚C
C
L
=
50 pF
R
L
=
500Ω
Min Typ Max
f
max
Maximum Operating Frequency 75 MHz
t
OSHL
Maximum Skew Common Edge 300 ps
Output-to-Output Variation (Note 2)
t
OSLH
Maximum Skew Common Edge 300 ps
Output-to-Output Variation (Note 2)
t
PS
Maximum Skew 2.5 ns
Pin (Signal) Transition Variation (Note 3)
t
RISE
Rise Time/Fall Time 1.75 ns
t
FALL
(from 0.8V to 2.0V/2.0V to 0.8V)
T
HIGH
Time High 4 ns
T
LOW
Time Low 4 ns
Note 2: Output-to-Output Skew is defined as the absolute value of the difference between the actual propagation delay for any outputs within the same packaged
device. The specifications apply to any outputs switching in the same direction either HIGH-to-LOW (t
OSHL
) or LOW-to-HIGH (t
OSLH
) or in opposite directions both
HL and LH (t
OST
). Limits are characterized and guaranteed by design@66 MHz.
Note 3: Pin transition skew is the absolute difference between HIGH-to-LOW and LOW-to-HIGH propagation delay, measured at a given output pin.
Note 4: Refer to Minimum Skew Parameters Measurement Information Chart for definitions of each skew specification.
Note 5: Load capacitance includes the test jig.
Timing Diagrams
DS011956-5
CGS74LCT2524
www.national.com3
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Timing Diagrams (Continued)
Test Circuit
Ordering Information
(Contact NSC Marketing for specific date of availability)
DS011956-6
DS011956-4
DS011956-7
RLis 500Ω
C
L
is 50 pF for all propagation delays and skew measurements.
DS011956-8
CGS74LCT2524
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Physical Dimensions inches (millimeters) unless otherwise noted
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COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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whose 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.
2. A critical component is 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
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8-Lead (0.150" Wide) Molded Small Outline Package, JEDEC
Order Number CGS74LCT2524M
NS Package Number M08A
CGS74LCT2524 1 to 4 Minimum Skew (300 ps) 3V Clock Driver
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
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