Freescale Semiconductor
Technical Data
3.3 V/2.5 V LVCMOS 1:12 Clock
Fanout Buffer
The Freescale Semiconductor, Inc. MPC9448 is a 3.3 V or 2.5 V compatible,
1:12 clock fanout buffer targeted for high performance clock tree applications.
With output frequencies up to 350 MHz and output skews less than 150 ps, the
device meets the needs of most demanding clock applications.
Features
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12 LVCMOS compatible clock outputs
Selectable LVCMOS and differential LVPECL compatible clock inputs
Maximum clock frequency of 350 MHz
Maximum clock skew of 150 ps
Synchronous output stop in logic low state eliminates output runt pulses
High-impedance output control
3.3 V or 2.5 V power supply
Drives up to 24 series terminated clock lines
Ambient temperature range -40°C to +85°C
32-Lead LQFP packaging
32-lead Pb-free package available
Supports clock distribution in networking, telecommunication and computing
applications
Pin and function compatible to MPC948
Document Number: MPC9448
Rev. 5, 1/2005
MPC9448
LOW VOLTAGE
3.3 V/2.5 V LVCMOS 1:12
CLOCK FANOUT BUFFER
FA SUFFIX
32-LEAD LQFP PACKAGE
CASE 873A-03
AC SUFFIX
32-LEAD LQFP PACKAGE
Pb-FREE PACKAGE
CASE 873A-03
Functional Description
The MPC9448 is specifically designed to distribute LVCMOS compatible clock signals up to a frequency of 350 MHz. Each
output provides a precise copy of the input signal with a near zero skew. The outputs buffers support driving of 50 Ω terminated
transmission lines on the incident edge. Each output is capable of driving either one parallel terminated or two series terminated
transmission lines.
Two selectable, independent clock inputs are available, providing support of LVCMOS and differential LVPECL clock distribution systems. The MPC9448 CLK_STOP control is synchronous to the falling edge of the input clock. It allows the start and stop
of the output clock signal only in a logic low state, thus eliminating potential output runt pulses. Applying the OE control will force
the outputs into high-impedance mode.
All inputs have an internal pull-up or pull-down resistor preventing unused and open inputs from floating. The device supports
a 2.5 V or 3.3 V power supply and an ambient temperature range of -40°C to +85°C. The MPC9448 is pin and function compatible
but performance-enhanced to the MPC948.
© Freescale Semiconductor, Inc., 2005. All rights reserved.
