MAX9492 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – Multiple-Output Clock Generator with Spread Spectrum

19-3683; Rev 0; 5/05
Multiple-Output Clock Generator
with Spread Spectrum
General Description
The MAX9492 frequency synthesizer is designed to
generate multiple clocks for clock distribution in net-
work routers or switches. The device provides a total of
six buffered clock outputs (CLK1 to CLK6). CLK1 is the
buffered output of the reference clock. CLK2 through
CLK6 are independently programmable to generate
eight different frequencies based on a 25MHz input
crystal: 133, 125, 83, 66, 62.5, 50, 33, and 25MHz. All
the outputs are LVCMOS single-ended signals. Either a
25MHz crystal or an external clock can serve as the
input reference clock. The MAX9492 incorporates two
phase-locked loops (PLLs) with two internal loop filters.
Select the MAX9492’s output clock frequency by pro-
gramming on-chip registers through the MAX9492’s
I²C* interface. The device also features spread-spec-
trum capability to reduce electromagnetic interference
(EMI). This technique allows spreading the fundamental
energy over a wider frequency range, hence reducing
the respective energy amplitude. The output frequency
spectrum is downspread by -1.25% or -2.5%.
The MAX9492 operates from a 3.3V supply and is guar-
anteed over the extended temperature range (-40°C to
+85°C). The device is available in a space-saving,
20-pin, TQFN, 5mm x 5mm package.
Features
o Five LVCMOS Outputs with Independent
Frequency Selections
o One Buffered Reference Clock Output
o Eight Selectable Frequencies: 133, 125, 83, 66,
62.5, 50, 33, and 25MHz
o Crystal or an Input-Clock-Based Clock Reference
o Output Frequency Programmed Through I²C
Interface
o 0, -1.25%, or -2.5% Selectable Downspreading
Rate
o Low Output Period Jitter
(Without Spread Spectrum) < 10ps_RMS
o <220ps Output-to-Output Skew
o Available in 20-Lead, 5mm x 5mm, TQFN Package
o +3.3V Supply
o -40°C to +85°C Extended Temperature Range
Applications
Network Routers
Telecom/Networking Equipment
Storage Area Networks/Network Attached
Storage
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
20 Thin QFN-EP**
MAX9492ETP -40°C to +85°C 5mm x 5mm x
0.8mm
**EP = Exposed pad.
T2055-3
Typical Operating Circuit and Pin Configuration appear at
end of data sheet.
*Purchase of I²C components from Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a
license under the Philips I²C Patent Rights to use these components in an I²C system, provided that the system conforms to the I²C
Standard Specification as defined by Philips.
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For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.