ICS527-02 Ver la hoja de datos (PDF) - Integrated Circuit Systems
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ICS527-02 Datasheet PDF : 8 Pages
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ICS527-02
Clock Slicer User Configurable PECL Input Zero Delay Buffer
the correct clock when mounted on the board. It is also
possible to connect the inputs to parallel I/O ports in
order to switch frequencies.
The output of the ICS527-02 can be determined by the
following simple equation:
FB
Frequency
=
Input
Frequency ×
-F---D-----W-------+-----2--
RDW + 2
Where:
Reference Divider Word (RDW) = 0 to 127
Feedback Divider Word (FDW) = 0 to 127
FB Frequency is the same as either CLK1 or
CLK2 depending on feedback connection
Also, the following operating ranges should be
observed:
300kHz
<
-I-n---p----u---t----F---r--e----q---u---e----n---c---y-
RDW + 2
<
20
MHz
S0 and S1 should be selected depending on the
frequency of CLK1. 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. Also, this
example assumes CLK1 is connected to FBIN.
If you need assistance determining the optimum divider
settings, please send an e-mail to
mk-support@icst.com with the desired input clock and
the desired output frequency.
Typical Example
The layout diagram below will produce the waveforms shown on the right.
VDD
0.01µF
40 MHz
40 MHz
R5
R6
DIV2
S0
S1
VDD
PECLIN
PECLIN
GND
OECLK2
F0
F1
F2
F3
R4
R3
R2
R1
R0
VDD
CLK1
CLK2
GND
PDTS
FBIN
F6
F5
F4
0.01µF
33Ω
33Ω
50 MHz
SYNC
40 MHz
PECLIN
PECLIN
50 MHz
CLK1
SYNC
CLK2
Note: The series termination resistor is located before the feedback trace
MDS 527-02 F
4
Revision 022806
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
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