LOW VOLTAGE 1:18 CLOCK DISTRIBUTION CHIP

MPC940L

IDT™ / ICS™ 1:18 CLOCK DISTRIBUTION CHIP

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MPC940L REV 7 JUNE 5, 2007

The MPC940L is a 1:18 low voltage clock distribution chip with 2.5 V or 3.3 V LVCMOS

output capabilities. The device features the capability to select either a differential

LVPECL or an LVCMOS compatible input. The 18 outputs are 2.5 V or 3.3 V LVCMOS

compatible and feature the drive strength to drive 50

Ω series or parallel terminated

transmission lines. With output-to-output skews of 150 ps, the MPC940L is ideal as a

clock distribution chip for the most demanding of synchronous systems. The 2.5 V outputs

also make the device ideal for supplying clocks for a high performance microprocessor

based design. For a similar device at a lower price/performance point, the reader is

referred to the MPC9109.

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LVPECL or LVCMOS Clock Input

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2.5 V LVCMOS Outputs for Pentium II Microprocessor Support

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150 ps Maximum Output-to-Output Skew

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Maximum Output Frequency of 250 MHz

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32-Lead LQFP Packaging

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32-Lead Pb-Free Package Available

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Dual or Single Supply Device:

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With a low output impedance (

≈20 Ω), in both the HIGH and LOW logic states, the

output buffers of the MPC940L are ideal for driving series terminated transmission lines.

With a 20

Ω output impedance the 940L has the capability of driving two series terminated

lines from each output. This gives the device an effective fanout of 1:36. If a lower output

impedance is desired please see the MPC942 data sheet.

The differential LVPECL inputs of the MPC940L allow the device to interface directly

with a LVPECL fanout buffer like the MC100EP111 to build very wide clock fanout trees

or to couple to a high frequency clock source. The LVCMOS input provides a more standard interface for applications requiring only a

single clock distribution chip at relatively low frequencies. In addition, the two clock sources can be used to provide for a test clock

interface as well as the primary system clock. A logic HIGH on the LVCMOS_CLK_SEL pin will select the LVCMOS level clock input. All

inputs of the MPC940L have internal pullup/pulldown resistors so they can be left open if unused.

The MPC940L is a single or dual supply device. The device power supply offers a high degree of flexibility. The device can operate

with a 3.3 V core and 3.3 V output, a 3.3 V core and 2.5 V outputs as well as a 2.5 V core and 2.5 V outputs. The 32-lead LQFP package

was chosen to optimize performance, board space and cost of the device. The 32-lead LQFP has a 7x7 mm body size with a conservative

0.8 mm pin spacing.

MPC940L

LOW VOLTAGE

1:18 CLOCK

DISTRIBUTION CHIP

FA SUFFIX

32-LEAD LQFP PACKAGE

CASE 873A-04

AC SUFFIX

32-LEAD LQFP PACKAGE

Pb-FREE PACKAGE

CASE 873A-04

Pentium II is a trademark of Intel Corporation.