DATASHEET
LOW SKEW 1 TO 4 CLOCK BUFFER ICS621
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 1
ICS621 REV G 051310
Description
The ICS621 is a low skew, single input to four output, clock
buffer. The device operates from a single 1.2 to 1.8 volt
supply and has a 3.3 volt tolerant input, making it ideal for
level translation.
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 skew outputs (150 ps)
•Packaged in 8-pin SOIC or 8-pin DFN (2x2mm)
•RoHS 5 or RoHS 6 (lead-free) package
•Low power CMOS technology
•Operating voltages of 1.2 V to 1.8 V
•Output Enable pin tri-states outputs
•3.3 V tolerant input clock
•Industrial or commercial temperature ranges
Block Diagram
Q0
ICLK
Q1
Q2
Q3
Output Enable
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 2
ICS621 REV G 051310
Pin Assignment (8-pin SOIC) Pin Assignment (8-pin DFN)
Pin Descriptions
External Components
A minimum number of external components are required for proper operation. A decoupling capacitor of 0.01 μF
should be connected between VDD on pin 7 and GND on pin 6, as close to the device as possible. A 33 Ω 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 ICS621 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 30Ω series termination on one output (with 33Ω on
the others) will cause at least 15 ps of skew.
1
2
3
45
6
7
8
ICLK
Q1
Q2
Q3 Q4
OE
VDD
GND
1
Q3
Q2 GND
VDDQ1
Q4
ICLK OE
5
8
4
Pin
Number
Pin
Name
Pin
Type
Pin Description
1 ICLK Input Clock Input. 3.3 V tolerant input.
2 Q1 Output Clock Output 1.
3 Q2 Output Clock Output 2.
4 Q3 Output Clock Output 3.
5 Q4 Output Clock Output 4.
6 GND Power Connect to ground.
7 VDD Power Connect to +1.2 V or +1.8 V.
8 OE Input Output Enable. Tri-states outputs when low. Connect to VDD for normal operation.
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 3
ICS621 REV G 051310
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS621. 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.
Recommended Operation Conditions
Item Rating
Supply Voltage, VDD 5 V
Output Enable and All Outputs -0.5 V to VDD+0.5 V
ICLK -0.5 V to 3.6 V (VDD > 0V)
Ambient Operating Temperature (industrial) -40 to +85 °C
Ambient Operating Temperature (commercial) 0 to +70 °C
Storage Temperature -65 to +150°C
Junction Temperature 125°C
Soldering Temperature 260°C
Parameter Min. Typ. Max. Units
Ambient Operating Temperature (industrial) -40 +85 °C
Ambient Operating Temperature (commercial) 0 +70 °C
Power Supply Voltage (measured in respect to GND) 1.14 1.89 V
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 4
ICS621 REV G 051310
DC Electrical Characteristics
VDD=1.2 V ±5%, Ambient temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
Notes: 1. Nominal switching threshold is VDD/2
VDD=1.5 V ±5%, Ambient temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
Notes: 1. Nominal switching threshold is VDD/2
VDD=1.8 V ±5%, Ambient temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
Notes: 1. Nominal switching threshold is VDD/2
Parameter Symbol Conditions Min. Typ. Max. Units
Operating Voltage VDD 1.14 1.26 V
Input High Voltage VIH Note 1, ICLK, OE 0.65VDD 3.6 V
Input Low Voltage VIL Note 1, ICLK, OE 0.35VDD V
Output High Voltage VOH IOH = -2 mA 0.75VDD V
Output Low Voltage VOL IOL = 2 mA 0.25VDD V
Operating Supply Current IDD No load, 133 MHz TBD mA
Nominal Output Impedance ZO20 Ω
Input Capacitance CIN ICLK, OE pin 5 pF
Short Circuit Current IOS ±20 mA
Parameter Symbol Conditions Min. Typ. Max. Units
Operating Voltage VDD 1.425 1.575 V
Input High Voltage VIH Note 1, ICLK, OE 0.65VDD 3.6 V
Input Low Voltage VIL Note 1, ICLK, OE 0.35VDD V
Output High Voltage VOH IOH = -6 mA 0.75VDD V
Output Low Voltage VOL IOL = 6 mA 0.25VDD V
Operating Supply Current IDD No load, 133 MHz 25 mA
Nominal Output Impedance ZO20 Ω
Input Capacitance CIN ICLK, OE pin 5 pF
Short Circuit Current IOS ±28 mA
Parameter Symbol Conditions Min. Typ. Max. Units
Operating Voltage VDD 1.71 1.89 V
Input High Voltage, ICLK VIH Note 1, ICLK, OE 0.65VDD 3.6 V
Input Low Voltage, ICLK VIL Note 1, ICLK, OE 0.35VDD V
Output High Voltage VOH IOH = -8 mA 1.35 V
Output Low Voltage VOL IOL = 8 mA 0.45 V
Operating Supply Current IDD No load, 133 MHz 50 mA
Nominal Output Impedance ZO20 Ω
Input Capacitance CIN ICLK, OE pin 5 pF
Short Circuit Current IOS ±50 mA
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 5
ICS621 REV G 051310
AC Electrical Characteristics
VDD = 1.2 V ±5%, Ambient Temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
VDD = 1.5 V ±5%, Ambient Temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
VDD = 1.8 V ±5%, Ambient Temperature -40 to +85°C or 0 to +70°C, unless stated otherwise
Notes: 1. With rail to rail input clock
2. Between any 2 outputs with equal loading.
3. Measured with a 15 pF load.
Thermal Characteristics
Parameter Symbol Conditions Min. Typ. Max. Units
Input Frequency 0 100 MHz
Output Rise Time tOR 20% to 80%, Note 3 1.0 1.5 ns
Output Fall Time tOF 80% to 20%, Note 3 1.0 1.5 ns
Propagation Delay Note 1 2.2 3 5 ns
Output to Output Skew Note 2 Rising edges at VDD/2 0 ±150 ps
Parameter Symbol Conditions Min. Typ. Max. Units
Input Frequency 0 166 MHz
Output Rise Time tOR 20% to 80%, Note 3 1.0 1.5 ns
Output Fall Time tOF 80% to 20%, Note 3 1.0 1.5 ns
Propagation Delay Note 1 2.2 3 5 ns
Output to Output Skew Note 2 Rising edges at VDD/2 0 ±150 ps
Parameter Symbol Conditions Min. Typ. Max. Units
Input Frequency 0 200 MHz
Output Rise Time tOR 20% to 80%, Note 3 1.0 1.5 ns
Output Fall Time tOF 80% to 20%, Note 3 1.0 1.5 ns
Propagation Delay Note 1 2.2 3 5 ns
Output to Output Skew Note 2 Rising edges at VDD/2 0 ±150 ps
Parameter Symbol Conditions Min. Typ. Max. Units
Thermal Resistance Junction to
Ambient
θJA Still air 150 °C/W
θJA 1 m/s air flow 140 °C/W
θJA 3 m/s air flow 120 °C/W
Thermal Resistance Junction to Case θJC 40 °C/W
Case Temperature 120 °C
Thermal Resistance Junction to Top
of Case
Ψ
JT Still air 20 °C/W
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 6
ICS621 REV G 051310
Package Outline and Package Dimensions (8-pin DFN 2x2mm, 0.5mm pitch)
Package dimensions are kept current with JEDEC Publication No. 95,
Millimeters
Symbol Min Max
A 0.80 1.00
A1 0 0.05
A3 0.20 Reference
b 0.20 0.30
N8
ND4
NE0
D 2.00 BASIC
E 2.00 BASIC
e 0.50 BASIC
D2 1.05 1.25
E2 0.45 0.65
L 0.20 0.40
aaa 0.15
bbb 0.10
ccc 0.10
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 7
ICS621 REV G 051310
Package Outline and Package Dimensions (8-pin SOIC, 150 Mil. Narrow Body)
Package dimensions are kept current with JEDEC Publication No. 95
INDEX
AREA
1 2
8
D
E
SEATING
PLANE
A1
A
e
- C -
B
.10 (.004) C
C
L
H
h x 45
*For reference only. Controlling dimensions in mm.
Millimeters Inches*
Symbol Min Max Min Max
A 1.35 1.75 .0532 .0688
A1 0.10 0.25 .0040 .0098
B 0.330.51.013.020
C 0.19 0.25 .0075 .0098
D 4.80 5.00 .1890 .1968
E 3.80 4.00 .1497 .1574
e 1.27 BASIC 0.050 BASIC
H 5.80 6.20 .2284 .2440
h 0.250.50.010.020
L 0.401.27.016.050
α0°8°0°8°
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 8
ICS621 REV G 051310
Ordering Information
“LF” suffix to the part number are the Pb-Free configuration and are RoHS compliant.
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) result from
its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other
applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are
not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT
does not authorize or warrant any IDT product for use in life support devices or critical medical instruments.
Part / Order Number Marking Shipping Packaging Package Temperature
621MILF 621MILF Tubes 8-pin SOIC -40 to +85°C
621MILFT 621MILF Tape and Reel 8-pin SOIC -40 to +85°C
621MLF 621MLF Tubes 8-pin SOIC 0 to +70°C
621MLFT 621MLF Tape and Reel 8-pin SOIC 0 to +70°C
621NLFT 1NL Tape and Reel 8-pin DFN 0 to +70°C
621NILFT 1IL Tape and Reel 8-pin DFN -40 to +85°C
ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
IDT®
LOW SKEW 1 TO 4 CLOCK BUFFER 9
ICS621 REV G 051310
Revision History
Rev. Originator Date Description of Change
A S. Sharma 06/08/06 New device/datasheet; Preliminary release.
B S. Sharma 03/09/07 Removed Tape and Reel part number from DFN package ordering info.
C 05/27/08 Removed “Preliminary” and updated part ordering info.
D R.Willner 08/01/08 Correct VIH values to reflect 3.3 V tolerant clock input
E 10/27/09 Added EOL note for non-green parts
F 05/13/10 Removed EOL note and non-green parts
G K.B. 05/13/10 Corrected DFN topmark.
© 2010 Integrated De vice Technology, Inc. All rights reserved. Product spe cifications subject to change with out notice. IDT, ICS, and th e IDT logo are trademarks of Integrated
Device Tec hnology, Inc. Accelerated Thinking is a service mark of Integrated De vice Technology, Inc. All other brands, pr oduct names and marks are or m ay be trademarks or
registered trademarks used to identify products or services of their respective owners.
Printed in USA
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Integrated Device Technology, Inc.
www.idt.com
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800-345-7015
408-284-8200
Fax: 408-284-2775
For Tech Support
www.idt.com/go/clockhelp
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ICS621
LOW SKEW 1 TO 4 CLOCK BUFFER FAN OUT BUFFER
