Low Skew 1 to 4 Clock Buffer
74FCT38074S
DATASHEET
Description
The 74FCT38074S is a low skew, single input to four output,
clock buffer. The 74FCT38074S has best in class additive
phase Jitter of sub 50 fsec.
IDT makes many non-PLL and PLL based low skew output
devices as well as Zero Delay Buffers to synchronize clocks.
Contact us for all of your clocking needs.
Features
•
•
•
•
•
•
•
•
Low additive phase jitter RMS: 50fs
Extremely low skew outputs (50ps)
Low cost clock buffer
Packaged in 8-pin SOIC and 8-pin DFN, Pb-free
Input/Output clock frequency up to 200 MHz
Low power CMOS technology
Operating voltages of 1.8V to 3.3V
Extended temperature range (-40° to +105°C)
Block Diagram
Q1
Q2
ICLK
Q3
Q4
74FCT38074S REVISION A 03/18/15
1
©2015 Integrated Device Technology, Inc.
74FCT38074S DATASHEET
Pin Assignments
VDD
VDD
ICLK
GND
1
2
3
4
8-pin SOIC
8
7
6
5
Q4
Q3
Q2
Q1
VDD
VDD
ICLK
GND
1
2
3
4
8
7
6
5
Q4
Q3
Q2
Q1
8-pin DFN
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
Pin
Name
VDD
VDD
ICLK
GND
Q1
Q2
Q3
Q4
Pin
Type
Power
Power
Input
Power
Output
Output
Output
Output
Connect to +1.8V, +2.5 V, or +3.3 V.
Connect to +1.8V, +2.5 V, or +3.3 V.
Clock input.
Connect to ground.
Clock output 1.
Clock Output 2.
Clock Output 3.
Clock Output 4.
Pin Description
External Components
A minimum number of external components are required for proper operation. A decoupling capacitor of 0.01µF should be
connected between VDD on pins 1 and 2, and GND on pin 4, as close to the device as possible. A 33
series terminating resistor
may be used on each clock output if the trace is longer than 1 inch.
To achieve the low output skew that the 74FCT38074S is capable of, careful attention must be paid to board layout. Essentially,
all four outputs must have identical terminations, identical loads and identical trace geometries. If they do not, the output skew
will be degraded. For example, using a 30
series termination on one output (with 33
on the others) will cause at least 15 ps
of skew.
LOW SKEW 1 TO 4 CLOCK BUFFER
2
REVISION A 03/18/15
74FCT38074S DATASHEET
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the 74FCT38074S. These ratings, which are standard
values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these or any other
conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
rating conditions for extended periods can affect product reliability. Electrical parameters are guaranteed only over the
recommended operating temperature range.
Item
Supply Voltage, VDD
Outputs
ICLK
Ambient Operating Temperature (extended)
Storage Temperature
Junction Temperature
Soldering Temperature
3.465V
-0.5 V to VDD+0.5 V
3.465V
-40° to +105°C
-65° to +150°C
125°C
260°C
Rating
Recommended Operation Conditions
Parameter
Ambient Operating Temperature (extended)
Power Supply Voltage (measured in respect to GND)
Min.
-40
+1.71
Typ.
Max.
+105
+3.465
Units
C
V
REVISION A 03/18/15
3
LOW SKEW 1 TO 4 CLOCK BUFFER
74FCT38074S DATASHEET
DC Electrical Characteristics
(VDD = 1.8V, 2.5V, 3.3V)
VDD=1.8V ±5%
, Ambient temperature -40° to +105°C, unless stated otherwise
Parameter
Operating Voltage
Input High Voltage, ICLK
Input Low Voltage, ICLK
Output High Voltage
Output Low Voltage
Operating Supply Current
Nominal Output Impedance
Input Capacitance
Symbol
VDD
V
IH
V
IL
V
OH
V
OL
IDD
Z
O
C
IN
Conditions
Note 1
Note 1
I
OH
= -10 mA
I
OL
= 10 mA
No load, 135 MHz
ICLK
Min.
1.71
0.7xVDD
1.3
Typ.
Max.
1.89
VDD
0.3xVDD
0.35
Units
V
V
V
V
V
mA
pF
13
17
5
Notes: 1. Nominal switching threshold is VDD/2
VDD=2.5 V ±5%
, Ambient temperature -40° to +105°C, unless stated otherwise
Parameter
Operating Voltage
Input High Voltage, ICLK
Input Low Voltage, ICLK
Output High Voltage
Output Low Voltage
Operating Supply Current
Nominal Output Impedance
Input Capacitance
Symbol
VDD
V
IH
V
IL
V
OH
V
OL
IDD
Z
O
C
IN
Conditions
Note 1
Note 1
I
OH
= -16 mA
I
OL
= 16 mA
No load, 135 MHz
ICLK
Min.
2.375
0.7xVDD
1.8
Typ.
Max.
2.625
VDD
0.3xVDD
0.5
Units
V
V
V
V
V
mA
pF
18
17
5
VDD=3.3 V ±5%
, Ambient temperature -40° to +105°C, unless stated otherwise
Parameter
Operating Voltage
Input High Voltage, ICLK
Input Low Voltage, ICLK
Output High Voltage
Output Low Voltage
Operating Supply Current
Nominal Output Impedance
Input Capacitance
Symbol
VDD
V
IH
V
IL
V
OH
V
OL
IDD
Z
O
C
IN
Conditions
Note 1
Note 1
I
OH
= -25 mA
I
OL
= 25 mA
No load, 135 MHz
ICLK
Min.
3.15
0.7xVDD
2.2
Typ.
Max.
3.45
VDD
0.3xVDD
0.7
Units
V
V
V
V
V
mA
pF
22
17
5
LOW SKEW 1 TO 4 CLOCK BUFFER
4
REVISION A 03/18/15
74FCT38074S DATASHEET
AC Electrical Characteristics
(VDD = 1.8V, 2.5V, 3.3V)
VDD = 1.8V ±5%
, Ambient Temperature -40° to +105°C, unless stated otherwise
Parameter
Input Frequency
Output Rise Time
Output Fall Time
Start-up Time
Propagation Delay
Buffer Additive Phase Jitter, RMS
Output to Output Skew
Device to Device Skew
t
OR
t
OF
t
START-UP
0.36 to 1.44 V, C
L
=5 pF
1.44 to 0.36 V, C
L
=5 pF
Part start-up time for valid
outputs after VDD ramp-up
Note 1
125MHz, Integration Range:
12kHz-20MHz
Rising edges at VDD/2, Note 2
Rising edges at VDD/2
50
1.5
2.5
Symbol
Conditions
Min.
0
Typ.
0.6
0.6
Max.
200
1.0
1.0
2
4
0.05
65
200
Units
MHz
ns
ns
ms
ns
ps
ps
ps
VDD = 2.5 V ±5%
, Ambient Temperature -40° to +105°C, unless stated otherwise
Parameter
Input Frequency
Output Rise Time
Output Fall Time
Start-up Time
Propagation Delay
Buffer Additive Phase Jitter, RMS
Output to Output Skew
Device to Device Skew
t
OR
t
OF
t
START-UP
0.5 to 2.0 V, C
L
=5 pF
2.0 to 0.5 V, C
L
=5 pF
Part start-up time for valid
outputs after VDD ramp-up
Note 1
125MHz, Integration Range:
12kHz-20MHz
Rising edges at VDD/2, Note 2
Rising edges at VDD/2
50
1.8
2.5
Symbol
Conditions
Min.
0
Typ.
0.6
0.6
Max.
200
1.0
1.0
2
4.5
0.05
65
200
Units
MHz
ns
ns
ms
ns
ps
ps
ps
VDD = 3.3 V ±5%
, Ambient Temperature -40° to +105°C, unless stated otherwise
Parameter
Input Frequency
Output Rise Time
Output Fall Time
Start-up Time
Propagation Delay
Buffer Additive Phase Jitter, RMS
Output to Output Skew
Device to Device Skew
t
OR
t
OF
t
START-UP
0.66 to 2.64 V, C
L
=5 pF
2.64 to 0.66 V, C
L
=5 pF
Part start-up time for valid
outputs after VDD ramp-up
Note 1
125MHz, Integration Range:
12kHz-20MHz
Rising edges at VDD/2, Note 2
Rising edges at VDD/2
50
1.5
2.5
Symbol
Conditions
Min.
0
Typ.
0.6
0.6
Max.
200
1.0
1.0
2
4
0.05
65
200
Units
MHz
ns
ns
ms
ns
ps
ps
ps
Notes:
1. With rail to rail input clock
2. Between any 2 outputs with equal loading.
3. Duty cycle on outputs will match incoming clock duty cycle. Consult IDT for tight duty cycle clock generators.
REVISION A 03/18/15
5
LOW SKEW 1 TO 4 CLOCK BUFFER
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