DATASHEET
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
Description
Features
The ICS557-06 is a two to four differential clock mux
designed for use in PCI-Express applications. The device
selects one of the two differential HCSL input pairs and fans
out to four pairs of differential HCSL or LVDS outputs.
•
•
•
•
•
•
•
•
•
Packaged in 20-pin TSSOP
Pb (lead) free packaging
Operating voltage of 3.3 V
Low power consumption
Input differential clock of up to 200 MHz
Jitter 60 ps (cycle-to-cycle)
Output-to-output skew of 50 ps
Available in industrial temperature range (-40 to +85°C)
For PCIe Gen2/3 applications, see the 5V41067A
Block Diagram
OE
VDD
2
CLKA
CLKA
IN1
CLKB
IN1
IN2
CLKB
MUX
2 to 1
CLKC
CLKC
IN2
CLKD
CLKD
2
SEL
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
GND
Rr (IREF)
PD
1
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Pin Assignment
Select Table
SEL
1
20
CLKA
VDDIN
2
19
CLKA
IN1
3
18
CLKB
IN1
4
17
CLKB
PD
5
16
GND
IN2
6
15
VDD
IN2
7
14
CLKC
OE
8
13
CLKC
GND
9
12
CLKD
IREF
10
11
CLKD
SEL
Input Pair
selected
0
1
IN2/ IN2
IN1/ IN1
20-pin (173 mil) TSSOP
Pin Descriptions
Pin
Pin
Name
Pin
Type
Pin Description
1
2
3
4
5
6
7
8
SEL
VDDIN
IN1
IN1
PD
IN2
IN2
OE
Input
Power
Input
Input
Input
Input
Input
Input
SEL=1 selects IN1/IN1. SEL =0 selects IN2/ IN2. Internal pull-up resistor.
Connect to +3.3 V. Supply voltage for Input clocks.
HCSL true input signal 1.
HCSL complimentary input signal 1.
Powers down the chip and tri-states outputs when low. Internal pull-up
HCSL true input signal 2.
HCSL complimentary input signal 2.
Provides fast output on, tri-states output (High = enable outputs; Low =
disable). Internal pull-up resistor outputs.
9
10
11
12
13
14
15
16
GND
Rr(IREF)
CLKD
CLKD
CLKC
CLKC
VDDOUT
GND
Power
Output
Output
Output
Output
Output
Power
Power
Connect to ground.
Precision resistor attached to this pin is connected to the internal current
Differential Complimentary output clock D.
Differential True output clock D.
Differential Complimentary output clock C.
Differential True output clock C.
Connect to +3.3 V. Supply Voltage for Output Clocks.
Connect to ground.
17
CLKB
Output
Differential Complimentary output clock B.
18
CLKB
Output
Differential True output clock B.
19
CLKA
Output
Differential Complimentary output clock A.
20
CLKA
Output
Differential True output clock A.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
2
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Application Information
Decoupling Capacitors
External Components
As with any high-performance mixed-signal IC, the
ICS557-06 must be isolated from system power supply
noise to perform optimally.
A minimum number of external components are required for
proper operation. Decoupling capacitors of 0.01 μF should
be connected between VDD and GND pairs (2,9 and 15,16)
as close to the device as possible.
Decoupling capacitors of 0.01µF must be connected
between each VDD and the PCB ground plane.
Current Reference Source Rr (Iref)
If board target trace impedance (Z) is 50Ω, then Rr = 475Ω
(1%), providing IREF of 2.32 mA, output current (IOH) is
equal to 6*IREF.
PCB Layout Recommendations
For optimum device performance and lowest output phase
noise, the following guidelines should be observed.
Load Resistors RL
Each 0.01µF decoupling capacitor should be mounted on
the component side of the board as close to the VDD pin as
possible. No vias should be used between decoupling
capacitor and VDD pin. The PCB trace to VDD pin should
be kept as short as possible, as should the PCB trace to the
ground via. Distance of the ferrite bead and bulk decoupling
from the device is less critical.
Since the clock outputs are open source outputs, 50 ohm
external resistors to ground are to be connected at each
clock output.
Output Termination
The PCI-Express differential clock outputs of the ICS557-06
are open source drivers and require an external series
resistor and a resistor to ground. These resistor values and
their allowable locations are shown in detail in the
PCI-Express Layout Guidelines section.
2) An optimum layout is one with all components on the
same side of the board, minimizing vias through other signal
layers (the ferrite bead and bulk decoupling capacitor can be
mounted on the back). Other signal traces should be routed
away from the ICS557-06.
The ICS557-06 can also be configured for LVDS compatible
voltage levels. See the LVDS Compatible Layout
Guidelines section.
This includes signal traces just underneath the device, or on
layers adjacent to the ground plane layer used by the device.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
3
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Output Structures
IREF
=2.3 mA
R R 475Ω
6*IREF
See Output Termination
Sections - Pages 3 ~ 5
General PCB Layout Recommendations
For optimum device performance and lowest output phase
noise, the following guidelines should be observed.
1. Each 0.01µF decoupling capacitor should be mounted on
the component side of the board as close to the VDD pin as
possible.
2. No vias should be used between decoupling capacitor
and VDD pin.
3. The PCB trace to VDD pin should be kept as short as
possible, as should the PCB trace to the ground via.
Distance of the ferrite bead and bulk decoupling from the
device is less critical.
4. An optimum layout is one with all components on the
same side of the board, minimizing vias through other signal
layers (any ferrite beads and bulk decoupling capacitors can
be mounted on the back). Other signal traces should be
routed away from the ICS557-06.This includes signal traces
just underneath the device, or on layers adjacent to the
ground plane layer used by the device.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
4
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
PCI-Express Layout Guidelines
Common Recommendations for Differential Routing
L1 length, Route as non-coupled 50 ohm trace.
L2 length, Route as non-coupled 50 ohm trace.
L3 length, Route as non-coupled 50 ohm trace.
RS
RT
Dimension or Value
0.5 max
0.2 max
0.2 max
33
49.9
Unit
inch
inch
inch
ohm
ohm
Differential Routing on a Single PCB
L4 length, Route as coupled microstrip 100 ohm differential trace.
L4 length, Route as coupled stripline 100 ohm differential trace.
Dimension or Value
2 min to 16 max
1.8 min to 14.4 max
Unit
inch
inch
Differential Routing to a PCI Express Connector
L4 length, Route as coupled microstrip 100 ohm differential trace.
L4 length, Route as coupled stripline 100 ohm differential trace.
Dimension or Value
0.25 to 14 max
0.225 min to 12.6 max
Unit
inch
inch
PCI-Express Device Routing
L1
L2
L4
RS
L1’
L4’
L2’
RS
ICS557-06
Output
Clock
RT
L3’
RT
L3
PCI-Express
Load or
Connector
Typical PCI-Express (HCSL) Waveform
700 mV
0
tOR
0.52 V
0.175 V
500 ps
500 ps
tOF
0.52 V
0.175 V
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
5
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
LVDS Compatible Layout Guidelines
Vdiff
Vp-p
0.45v
0.22v
0.58
0.28
0.80
0.40
0.60
0.3
R1a = R1b = R1
R2a = R2b = R2
Alternative T ermination for LVDS and other Common Differential Signals
Vcm
R1
R2
R3
R4
Note
1.08
33
150
100
100
0.6
33
78.7
137
100
0.6
33
78.7
none
100
ICS874003i-02 input compatible
1.2
33
174
140
100
Standard LVDS
LVDS Device Routing
Figure 3
L2
L1
R3
R1a
L4
R4
L4'
L2'
L1'
R1b
R2a
HCSL Output Buffer
R2b
L3'
Down Device
REF_CLK Input
L3
Typical LVDS Waveform
1325 mV
1000 mV
tOR
500 ps
1250 mV
1150 mV
500 ps
tOF
1250 mV
1150 mV
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
6
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS557-06. These ratings 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
Rating
Supply Voltage, VDD, VDDA
5.5 V
All Inputs and Outputs
-0.5 V to VDD+0.5 V
Ambient Operating Temperature (commercial)
0 to +70° C
Ambient Operating Temperature (industrial)
-40 to +85° C
Storage Temperature
-65 to +150° C
Junction Temperature
125° C
Soldering Temperature
260° C
ESD Protection (Input)
2000 V min. (HBM)
DC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85° C
Parameter
Symbol
Supply Voltage
Conditions
V
Input High Voltage1
Min.
Typ.
Max.
3.135
3.465
Units
VIH
OE, SEL, PD
2.0
VDD +0.3
V
VIL
OE, SEL, PD
VSS-0.3
0.8
V
Input Leakage Current
IIL
0 < Vin < VDD
-5
5
μA
Operating Supply Current
IDD
50Ω, 2pF
55
mA
IDDOE
OE =Low
20
mA
IDDPD
No load, PD =Low
400
μA
Input Low Voltage
1
2
Input Capacitance
CIN
Input pin capacitance
7
pF
Output pin capacitance
6
pF
5
nH
Output Capacitance
COUT
Pin Inductance
LPIN
Output Resistance
ROUT
CLK outputs
Pull-up Resistor
RPUP
SEL, OE, PD
3.0
kΩ
110
kΩ
1. Single edge is monotonic when transitioning through region.
2. Inputs with pull-ups/-downs are not included.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
7
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
AC Electrical Characteristics - CLKOUTA/CLKOUTB
Unless stated otherwise, VDD=3.3 V ±5%, Ambient Temperature -40 to +85° C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
200
MHz
HCSL termination
200
MHz
LVDS termination
100
Input Frequency
Output Frequency
Input High Voltage1,2
VIH
HCSL
660
700
Voltage1,2
VIL
HCSL
-150
0
Differential Input
Voltages
(VID)
LVDS
250
350
450
mV
Input Offset Voltage
Input Low
850
mV
mV
(VIS)
LVDS
1.125
1.25
1.375
V
Output High
Voltage1,2
VOH
HCSL
660
700
850
mV
Output Low
Voltage1,2
VOL
HCSL
-150
0
27
mV
Crossing Point
Voltage1,2
Absolute
250
350
550
mV
Crossing Point
Voltage1,2,4
Variation over all edges
140
mV
Jitter, Cycle-to-Cycle1,3
Rise
Fall
Time1,2
Time1,2
60
tOR
From 0.175 V to 0.525 V
175
332
tOF
From 0.525 V to 0.175 V
175
344
Rise/Fall Time
Variation1,2
Skew between Outputs
Duty
Measured at crossing point
Cycle1,3
45
ps
700
ps
700
ps
125
ps
50
ps
55
%
Time5
All outputs
10
us
Output Disable Time5
All outputs
10
us
Input to Output Delay
Input differential clock to output
differential clock delay measured at
mid point of input levels to mid pint of
output levels
4.5
ns
Output Enable
1
Test setup is RL=50 ohms with 2 pF, Rr = 475Ω (1%).
2
Measurement taken from a single-ended waveform.
3
Measurement taken from a differential waveform.
4
Measured at the crossing point where instantaneous voltages of both CLKOUT and CLKOUT are equal.
5
CLKOUT pins are tri-stated when OE is Low asserted. CLKOUT is driven differential when OE is High unless its
PD = low.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
8
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Thermal Characteristics
Parameter
Symbol
Thermal Resistance Junction to
Ambient
Thermal Resistance Junction to Case
Conditions
Min.
Typ.
Max. Units
θ JA
Still air
93
° C/W
θ JA
1 m/s air flow
78
° C/W
θ JA
3 m/s air flow
65
° C/W
20
° C/W
θ JC
Marking Diagrams
(ICS557GI-06LF)
(ICS557G-06LF)
20
ICS
11
20
######
YYWW
557G06LF
1
ICS
10
11
######
YYWW
557GI06LF
1
10
Notes:
1. ###### is the lot code.
2. YYWW is the last two digits of the year, and the week number that the part was assembled.
3. “LF” denotes Pb free package.
4. “I” denotes industrial temperature.
5. Bottom marking: (origin). Origin = country of origin if not USA.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
9
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Package Outline and Package Dimensions (20-pin TSSOP, 173 Mil. Narrow Body)
Package dimensions are kept current with JEDEC Publication No. 95
Millimeters
20
Symbol
E1
A
A1
A2
b
c
D
E
E1
e
L
a
aaa
E
INDEX
AREA
1 2
D
Max
1.20
0.05
0.15
0.80
1.05
0.19
0.30
0.09
0.20
6.40
6.60
6.40 BASIC
4.30
4.50
0.65 Basic
0.45
0.75
0°
8°
-0.10
Min
Max
0.047
0.002
0.006
0.032
0.041
0.007
0.012
0.0035 0.008
0.252
0.260
0.252 BASIC
0.169
0.177
0.0256 Basic
0.018
0.030
0°
8°
-0.004
*For reference only. Controlling dimensions in mm.
A
A2
Min
Inches*
A1
c
-Ce
b
SEATING
PLANE
L
aaa C
Ordering Information
Part / Order Number
Marking
Shipping Packaging
Package
Temperature
557G-06LF
See Page 9
Tubes
20-pin TSSOP
0 to +70° C
557G-06LFT
Tape and Reel
20-pin TSSOP
0 to +70° C
557GI-06LF
Tubes
20-pin TSSOP
-40 to +85° C
557GI-06LFT
Tape and Reel
20-pin TSSOP
-40 to +85° C
"LF" suffix to the part number are the Pb-Free configuration, RoHS compliant.
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes
no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would 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.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
10
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Revision History
Rev.
Date
Originator
M
07/05/12
—
Description of Change
Changed the typical value of the "Input to Output Delay" parameter in the "AC Electrical
Characteristics - CLKOUTA/CLKOUTB" table from 3ns to 4.5ns.
IDT® 2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
11
ICS557-06
REV M 070512
ICS557-06
2 TO 4 DIFFERENTIAL PCIE GEN1 CLOCK MUX
PCIE FAN OUT BUFFER
Innovate with IDT and accelerate your future networks. Contact:
www.IDT.com
For Sales
For Tech Support
800-345-7015
408-284-8200
Fax: 408-284-2775
www.idt/go/clockhelp
Corporate Headquarters
Integrated Device Technology, Inc.
www.idt.com
© 2012 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT, ICS, and the IDT logo are trademarks of Integrated
Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or
registered trademarks used to identify products or services of their respective owners.
Printed in USA
IMPORTANT NOTICE AND DISCLAIMER
RENESAS ELECTRONICS CORPORATION AND ITS SUBSIDIARIES (“RENESAS”) PROVIDES TECHNICAL
SPECIFICATIONS AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING
REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND
OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for developers skilled in the art designing with Renesas products. You are solely responsible
for (1) selecting the appropriate products for your application, (2) designing, validating, and testing your application, and (3)
ensuring your application meets applicable standards, and any other safety, security, or other requirements. These
resources are subject to change without notice. Renesas grants you permission to use these resources only for
development of an application that uses Renesas products. Other reproduction or use of these resources is strictly
prohibited. No license is granted to any other Renesas intellectual property or to any third party intellectual property.
Renesas disclaims responsibility for, and you will fully indemnify Renesas and its representatives against, any claims,
damages, costs, losses, or liabilities arising out of your use of these resources. Renesas' products are provided only subject
to Renesas' Terms and Conditions of Sale or other applicable terms agreed to in writing. No use of any Renesas resources
expands or otherwise alters any applicable warranties or warranty disclaimers for these products.
(Rev.1.0 Mar 2020)
Corporate Headquarters
Contact Information
TOYOSU FORESIA, 3-2-24 Toyosu,
Koto-ku, Tokyo 135-0061, Japan
www.renesas.com
For further information on a product, technology, the most
up-to-date version of a document, or your nearest sales
office, please visit:
www.renesas.com/contact/
Trademarks
Renesas and the Renesas logo are trademarks of Renesas
Electronics Corporation. All trademarks and registered
trademarks are the property of their respective owners.
© 2020 Renesas Electronics Corporation. All rights reserved.