MPC9446
Rev. 3, 08/2005
Freescale Semiconductor
Technical Data
© Freescale Semiconductor, Inc., 2005. All rights reserved.
2.5 V and 3.3 V LVCMOS Clock
Fanout Buffer
The MPC9446 is a 2.5 V and 3.3 V compatible 1:10 clock distribution buffer
designed for low-voltage mid-range to high-performance telecom, networking
and computing applications. Both 3.3 V, 2.5 V and dual supply voltages are
supported for mixed-voltage applications. The MPC9446 offers 10 low-skew
outputs and 2 selectable inputs for clock redundancy. The outputs are
configurable and support 1:1 and 1:2 output to input frequency ratios. The
MPC9446 is specified for the extended temperature range of –40°C to 85°C.
Features
• Configurable 10 outputs LVCMOS clock distribution buffer
• Compatible to single, dual and mixed 3.3 V/2.5 V voltage supply
• Wide range output clock frequency up to 250 MHz
• Designed for mid-range to high-performance telecom, networking
and computer applications
• Supports applications requiring clock redundancy
• Maximum output skew of 200 ps (150 ps within one bank)
• Selectable output configurations per output bank
• Tristable outputs
• 32-lead LQFP package
• 32-lead Pb-free package available
• Ambient operating temperature range of –40 to 85°C
Functional Description
The MPC9446 is a full static fanout buffer design supporting clock frequencies up to 250 MHz. The signals are generated and
retimed on-chip to ensure minimal skew between the three output banks. Two independent LVCMOS compatible clock inputs are
available. This feature supports redundant clock sources or the addition of a test clock into the system design. Each of the three
output banks can be individually supplied by 2.5 V or 3.3 V supporting mixed voltage applications. The FSELx pins choose be-
tween division of the input reference frequency by one or two. The frequency divider can be set individually for each of the three
output banks. The MPC9446 can be rese,t and the outputs are disabled by deasserting the MR/OE
pin (logic high state). Assert-
ing MR/OE will enable the outputs.
All inputs accept LVCMOS signals while the outputs provide LVCMOS compatible levels with the capability to drive terminated
50 Ω transmission lines. Please consult the MPC9456 specification for a 1:10 mixed voltage buffer with LVPECL compatible in-
puts. For series terminated transmission lines, each of the MPC9446 outputs can drive one or two traces giving the devices an
effective fanout of 1:20. The device is packaged in a 7x7 mm
2
32-lead LQFP package.
FA SUFFIX
32-LEAD LQFP PACKAGE
CASE 873A-04
AC SUFFIX
32-LEAD LQFP PACKAGE
Pb-FREE PACKAGE
CASE 873A-04
MPC9446
LOW VOLTAGE SINGLE OR
DUAL SUPPLY 2.5 V AND 3.3 V
LVCMOS CLOCK
DISTRIBUTION BUFFER
