ICS527-04
MDS 527-04 D
1
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
Clock Slicer User Configurable PECL input Zero Delay Buffer
Description
The ICS527-04 Clock Slicer is the most flexible way to
generate an output clock from an input clock with zero
skew. The user can easily configure the device to
produce nearly any output clock that is multiplied or
divided from the input clock. The part supports
non-integer multiplications and divisions. Using
Phase-Locked Loop (PLL) techniques, the device
accepts an input clock up to 200 MHz and produces an
output clock up to 160 MHz.
The ICS527-04 aligns rising edges on PECLIN with
FBPECL at a ratio determined by the reference and
feedback dividers.
For other PECL output clocks, see the ICS507-01,
ICS525-03, or the MK3707. For PECL in and CMOS
out, see the ICS527-02. For CMOS in and PECL out
with zero delay, use the ICS527-03.
Features
Packaged as 28-pin SSOP (150 mil body)
Synchronizes fractional clocks rising edges
CMOS in to PECL out
PECL in to PECL out
Pin selectable dividers
Zero input to output skew
User determines the output frequency - no software
needed
Slices frequency or period
Input clock frequency of 1.5 MHz - 200 MHz
Output clock frequencies up to 160 MHz
Very low jitter
Duty cycle of 45/55
Operating voltage of 3.3 V
Advanced, low power CMOS process
Block Diagram
PECLIN
VDD
GND
2
2
PECLO
Reference
Divider
PECLIN
Phase Comparator,
Charge Pump, and
Loop Filter
VCO
Output
Divider
7
7
R6:R0
F6:F0
S1:S0
Feedback
Divider
1
0
Divide
by 2
FBPECL
FBPECL
1
0
Divide
by 2
VDD
RES
IRANGE
560 ohm
68 ohm
180 ohm
68 ohm
180 ohm
2
PECLO
VDD
VDD
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
2
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
Pin Assignment
28-pin (150 mil) SSOP
Output Frequency and Output
Divider Table
IRANGE Setting Table
Pin Descriptions
1 8
7
1 7
8
1 6
9
1 5
F B P E C L
1 0
F B P E C L
1 1
G N D
1 2
P E C L O
1 3
P E C L I N
1 4
P E C L I N
G N D
R E S
F 6
F 0
F 5
F 3
F 1
F 4
2 2
2 1
2 0
1 9
F 2
P E C L O
5
6
S 1
V D D
V D D
2 4
2 3
R 0
3
4
I R A N G E
S 0
R 1
2 6
2 5
R 2
1
2
R 5
R 6
R 3
2 8
2 7
R 4
S1
Pin 5
S0
Pin 4
Output Frequency (MHz)
PECLO Output Pair
0
0
10 - 80
0
1
5 - 40
1
0
2.5 - 20
1
1
20 -160
IRANGE
Criteria
0
if (FBPECL < 80 MHz) and (PECLIN < 80 MHz)
1
if (FBPECL > 80 MHz) or (PECLIN > 80 MHz)
Pin
Number
Pin
Name
Pin
Type
Pin Description
1 - 2
24 - 28
R5, R6,
R0-R4
Input
Reference divider word input pins determined by user. Forms a binary number
from 0 to 127. Internal pull-up.
3
IRANGE
Input
Set for proper frequency range of input clocks. See table above.
4 - 5
S0, S1
Input
Select pins for output frequency range. See table above. Internal pull-up.
6, 23
VDD
Power
Connect to +3.3 V.
7
FBPECL
Input
PECL feedback input to PLL.
8
FBPECL
Input
PECL feedback input to PLL.
9, 20
GND
Power
Connect to ground
10
PECLIN
Input
PECL input clock.
11
PECLIN
Input
Complementary PECL input clock.
12 - 18
F0-F6
Input
Feedback divider word input pins determined by user. Forms a binary number
from 0 to 127. Internal pull-up
19
RES
BIAS
Resistor connection to VDD for setting level of PECL outputs.
21
PECLO
Output
Complementary PECL output.
22
PECLO
Output
PECL output. Rising edge aligns with PECLIN when connected directly to
FBPECL.
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
3
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
External Components
Decoupling Capacitors
The ICS527-04 requires two 0.01
F decoupling
capacitors to be connected between VDD and GND,
one on each side of the chip. They must be connected
close to the device to minimize lead inductance. The
output levels can be adjusted for different output and
load impedances. Refer to application note MAN09 for
more information on the RES and resistor network
values for the output clocks.
PECL Termination Networks
The PECLO to FBPECL and PECLO to FBPECL
connections should be made directly underneath the
device, unless feedback is being routed through other
devices. The resistor divider networks should be placed
as close to the outputs as possible.
Typical 50
termination is shown in the Block Diagram
on page 1. For other termination schemes, see
MAN09.pdf.
Eliminating the Delay Through Buffers or
Other Components
More complicated feedback schemes can be used,
such as incorporating low skew, multiple output buffers
in the feedback path. An example of this is given later in
the datasheet. The fundamental property of the
ICS527-04 is that it aligns rising edges on CLKIN and
FBPECL at a ratio determined by the reference and
feedback dividers. This means that any delay in the
feedback path will cause the PECL output edge to lead
PECLIN by the delay amount. So, by taking the PECL
output from another device as the input to FBPECL, the
delay through the other device can be eliminated.
Setting the Clock Slicer
Use IRANGE to select the input frequency range. If
either the PECLIN or FBPECL pair frequencies are
greater than (or equal to) 80 MHz, connect IRANGE to
VDD, or let it float. If both frequencies are less than 80
MHz, connect IRANGE to ground.
Choose S1 and S0 from the table on page 2,
depending on the output frequency.
Finally, the divider settings should be selected.
Following is a description of how the dividers should be
set.
Determining ICS527-04 Divider Settings
The user has full control in setting the desired output
clock over the range shown in the table on page 2. The
user should connect the divider select input pins
directly to ground (or VDD, although this is not required
because of internal pull-ups) during Printed Circuit
Board layout, so that the ICS527-04 automatically
produces the correct clock when all components are
soldered. It is also possible to connect the inputs to
parallel I/O ports in order to switch frequencies. The
configuration inputs: IRANGE, S1, S0, R6...0, F6...0
are compatible with CMOS or TTL levels.
The output of the ICS527-04 can be determined by the
following simple equation:
Where:
Reference Divider Word (RDW) = 0 to 127
Feedback Divider Word (FDW) = 0 to 127
FB Frequency is the same as the output
frequency
Additionally, the following operating ranges should be
observed:
S1 and S0 should be selected depending on the
output frequency. The table on page 2 gives the
ranges.
The dividers are expressed as integers. For example, if
a 50 MHz output on CLK1 is desired from a 40 MHz
input, the reference divider word (RDW) should be 2
and the feedback divider word (FDW) should be 3
which gives the required 5/4 multiplication. If multiple
choices of dividers are available, then the lowest
numbers should be used. In this example, the output
divide (OD) should be selected to be 2. Then R6:R0 is
0000010, F6:F0 is 0000011 and S1:S0 is 00.
If you need assistance determining the optimum divider
settings, please send an e-mail to ics-mk@icst.com
with the desired input clock and the desired output
frequency.
FB Frequency
Input Frequency
FDW
2
+
RDW
2
+
------------------------
=
300kHz
Input Frequency
RDW
2
+
-------------------------------------------
<
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
4
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
Typical Example
The following connection diagram shows the implementation of the example from the previous section.
This will generate a 50 MHz clock synchronously with a 40 MHz input. The layout diagram below will
produce the waveforms shown on the bottom of the example.
F6
FBPECL
F5
F4
GND
F3
PECLIN
PECLIN
F0
F1
F2
PECL
PECL
GND
S1
VDD
R0
VDD
IRANGE
S0
R2
R1
R5
R6
R4
R3
FBPECL
RES
0.01
F
0.01
F
VDD
40 MHz
560
50 MHz
180
PECL output resistor network (50 ohm) is not
shown, but is identical to PECL
VDD
40 MHz
40 MHz
(PECLIN shown)
50 MHz PECL
50 MHz PECL
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
5
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
Multiple Output Example
In this example, an input clock of 125 MHz is used. Four low skew copies of 50 MHz PECL are required
aligned to the 125 MHz input clock. The following solution uses the ICS554-01A, which is a 1 to 4 PECL
buffer with low pin to pin skew.
Using the equation for selecting dividers gives:
If FDW = 0, then RDW = 3. This gives the required divide-by-5 function. Setting pin IRANGE = 1 (by leaving
it unconnected and using the internal pull-up) allows a higher speed input clock like the 125 MHz. The
FBPECL pair pins are connected to the Q1 outputs (chosen arbitrarily) of the ICS554. This aligns all the
outputs of the ICS554 with the 125 MHz input since the ICS527-04 aligns rising edges on the PECLIN and
FBPECL pins.
In this example, the resistor network needed for each PECLO output is represented by the
boxes.
125 MHz, PECLIN
50 MHz, PECLO
(Complementary outputs are not shown)
F6
FBPECL
F5
F4
GND
F3
PECLIN
PECLIN
F0
F1
F2
PECLO
PECLO
GND
S1
VDD
R0
VDD
IRANGE
S0
R2
R1
R5
R6
R4
R3
FBPECL
RES
0.01
F
0.01
F
VDD
Q2
Q0
GND
Q1
GND
Q2
Q0
VDD
VDD
OE
NC
Q1
0.01
F
I
C
S
5
5
4
-
01A
I
C
S
5
27-
0
4
The layout design above produces the waveforms shown below.
RN
50 MHz
125 MHz
RN
IN
IN
Q3
Q3
RN
RN
RN
RN
RN
RN
RN
RN
560
0.01
F
125 MHz
50 MHz = 125 MHz *
(FDW + 2)
(RDW + 2)
RN
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
6
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
PCB Layout Recommendations
For optimum device performance and lowest output
phase noise, the following guidelines should be
observed.
1) Each 0.01F decoupling capacitor should be
mounted on the component side of the board as close
to the VDD pin as possible. No via's 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.
2) PECL termination networks should be located as
close to the outputs as possible.
3) An optimum layout is one with all components on the
same side of the board, minimizing vias through other
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS527-04. These ratings,
which are standard values for ICS 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
7 V
All Inputs and Outputs
-0.5 V to VDD+0.5 V
Ambient Operating Temperature
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
0
+70
C
Power Supply Voltage (measured in respect to GND)
+3.15
+3.3
+3.45
V
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
7
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
DC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V 5%, Ambient Temperature 0 to +70
C
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V 5%, Ambient Temperature 0 to +70
C
Note 1: Assumes clocks with same rise time, measured from rising edges at VDD/2.
Thermal Characteristics
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Operating Voltage
VDD
3.15
3.3
3.45
V
Input High Voltage
V
IH
2
V
Input Low Voltage
V
IL
0.8
V
Peak to Peak Input
Voltage
Pins 7, 8, 10, 11
0.3
1
V
Common Mode Range
Pins 7, 8, 10, 11
VDD-1.4
VDD-0.6
V
Output High Voltage
V
OH
I
OH
= -12 mA
2.4
V
Output Low Voltage
V
OL
I
OL
= 12 mA
0.4
V
Operating Supply
Current
IDD
15 MHz in, 60 MHz
out, no load
8
mA
Input Capacitance
C
IN
4
pF
On-chip pull-up resistor
R
PU
configuration inputs
270
k
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Input Frequency
F
IN
1.5
200
MHz
Output Frequency, CLK1
F
OUT
0 to +70
C
4
160
MHz
Output Duty Cycle
t
OD
45
50
55
%
Absolute Clock Period Jitter
t
ja
Deviation from mean
90
ps
One sigma Clock Period Jitter
t
js
40
ps
Input to output skew
t
IO
PECLIN to PECLO,
Note 1
-250
250
ps
Device to device skew
t
pi
Common CLKIN,
measured at FBPECL
500
ps
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Thermal Resistance Junction to
Ambient
JA
Still air
100
C/W
JA
1 m/s air flow
80
C/W
JA
3 m/s air flow
67
C/W
Thermal Resistance Junction to Case
JC
60
C/W
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
8
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
Marking Diagram
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.
14
28
15
$$###-###
YYWW
ICS527R-04
ICS
1
Clock Slicer User Configurable PECL input Zero Delay Buffer
MDS 527-04 D
9
Revision 122804
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
ICS527-04
Package Outline and Package Dimensions
(28-pin SSOP, 150 mil Body, 0.025 mm Pitch)
Package dimensions are kept current with JEDEC Publication No. 95, MO-153
Ordering Information
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (ICS)
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 ICS. ICS reserves the right to change any
circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or
critical medical instruments
Part / Order Number
Marking
Shipping
packaging
Package
Temperature
ICS527R-04
ICS527R-04
Tubes
28-pin SSOP
0 to +70
C
ICS527R-04T
ICS527R-04
Tape and Reel
28-pin SSOP
0 to +70
C
INDEX
AREA
1 2
28
D
E1
E
SEATING
PLANE
A
1
A
A
2
e
- C -
b
aaa
C
c
L
Millimeters
Inches
Symbol
Min
Max
Min
Max
A
1.35
1.75
.053
.069
A1
0.10
0.25
.0040
.010
A2
--
1.50
--
.059
b
0.20
0.30
.008
.012
C
0.18
0.25
.007
.010
D
9.80
10.00
.386
.394
E
5.80
6.20
.228
.244
E1
3.80
4.00
.150
.157
e
0.635 Basic
0.025 Basic
L
0.40
1.27
.016
.050
0
8
0
8
aaa
--
0.10
--
0.004
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