MPC92474
Rev 0, 3/2005
Freescale Semiconductor
Technical Data
Freescale Semiconductor, Inc., 2005. All rights reserved.
Specifications and information herein are subject to change without notice.
PREL
IM
IN
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LVPECL Clock Synthesizer
w/Spread Spectrum
The MPC92474 is a 3.3 V compatible, PLL based clock synthesizer targeted
for high performance clock generation in mid-range to high-performance tele-
com, networking and computing applications. With output frequencies from
35 MHz to 700 MHz and the support of differential LVPECL output signals the
device meets the needs of the most demanding clock applications.
Features
35 MHz to 700 MHz synthesized clock output signal
Two differential LVPECL outputs
LVCMOS compatible control inputs
Two on-chip crystal oscillators for reference frequency generation
Spread Spectrum output for EMI reduction
Low Phase Noise
Serial programming interface
Parallel programming interface for power-up
48-lead LQFP packaging
48-lead Pb-free package available
SiGe Technology
Ambient temperature range 0
°C to +70°C
Functional Description
The MPC92474 is a PLL based clock synthesizer with dual LVPECL outputs.
The device uses a reference input that is selectable from 1 of 4 input sources.
These sources are either of two crystal oscillator inputs, a differential input or a sin-
gle-ended input clock. Each of the two internal crystal oscillators uses an external
quartz crystal as the basis of its frequency reference. The differential input will ac-
cept many differential input levels including industry standard LVPECL levels.
The selected input reference frequency is divided by a configurable P divider of either ÷1, ÷4 or ÷8 and then multiplied by the
internal PLL to the VCO frequency. The VCO within the PLL operates over a range of 560 to 700 MHz. Its output is then scaled
by two independant output dividers that may be configured by either the serial or parallel interfaces. The crystal oscillator fre-
quency fXTAL, the PLL feedback-divider M and the PLL post-dividers of NA and NB determine the output frequency of each of
the two LVPECL differential outputs. The PLL post-dividers of NA and NB are configured through either the serial or the parallel
interfaces, and can provide one of eight division ratios (1, 2, 3, 4, 5, 6, 8, or 16). The selected reference input is available on the
REF_CLK output pin.
In addition the MPC92474 has a TEST output that reflects various internal node values, and is controlled by the T[1:0] bits in
the serial data stream.
The MPC92474 offers spread spectrum modulation on the output frequency for system EMI reduction if desired. Spread spec-
trum defaults to a disabled state and is enabled through the serial interface. Both center spread and down spread formats may
be selected. Also the amount of spread spectrum modulation is selectable through the serial interface. See the Applications sec-
tion for additional details on Spread Spectrum operation and configuration.
The MPC92474 is available in a 48 lead LQFP package. A Pb-free package is also available.
MPC92474
LOW VOLTAGE
CLOCK SYNTHESIZER
w/SPREAD SPECTRUM
FA SUFFIX
48-LEAD LQFP PACKAGE
CASE 932-03
AC SUFFIX
48-LEAD LQFP PACKAGE
Pb-FREE PACKAGE
CASE 932-03
DATA SHEET
MPC92474
IDT LVPECL Clock Synthesizer w/Spread Spectrum
Freescale Timing Solutions Organization has been acquired by Integrated Device Technology, Inc
MPC92474
1
LVPECL Clock Synthesizer
w/Spread Spectrum