MPC9894 Datasheet, PDF (1/28 Pages) List of Unclassifed Manufacturers – Quad Input Redundant IDCS Clock Generator

Freescale Semiconductor
Technical Data
MPC9894
Rev 3, 1/2005
Quad Input Redundant IDCS Clock
Generator
MPC9894
The MPC9894 is a differential input and output, PLL-based Intelligent
Dynamic Clock Switch (IDCS) and clock generator specifically designed for
redundant clock distribution systems. The device receives up to four LVPECL
clock signals and generates eight phase-aligned output clocks. The MPC9894 is
able to detect failing clock signals and to dynamically switch to a redundant clock
signal. The switch from the failing clock to the redundant clock occurs without
interruption of the output clock signal (output clock slews to alignment). The
phase bump typically caused by a clock failure is eliminated. The device offers
eight low-skew clock outputs organized into four output banks, each configurable
to support the different clock frequencies. The extended temperature range of
the MPC9894 supports telecommunication and networking requirements.
QUAD INPUT REDUNDANT
IDCS CLOCK GENERATOR
Features
• 8 differential LVPECL output pairs
• Quad-redundancy reference clock inputs
• IDCS-on-chip intelligent dynamic clock switch
• Smooth output phase transition during clock failover switch/*
• Automatically detects clock failures
• Clock activity monitor
• Clock qualifier inputs
• Manual clock select and automatic switch modes
• 21.25 – 340 MHz output frequency range
• Specified frequency and phase slew rate on clock switch
• LVCMOS compatible control inputs and outputs
• External feedback enables zero-delay configurations
• Output enable/disable and static test mode (PLL bypass)
• Low-skew characteristics: maximum 50 ps⁽¹⁾ output-to-output
• I²C interface for device configuration
• Low cycle-to-cycle and period jitter
• IEEE 1149.1 JTAG Interface
• 100-ball MAPBGA package
• Supports 2.5 V or 3.3 V supplies with 2.5 V and 3.3 V I/O
• Junction temperature range –40°C to +110°C
VF SUFFIX
100-LEAD MAPBGA PACKAGE
CASE 1462-01
Functional Description
The MPC9894 is a quad differential redundant input clock generator. The device contains logic for clock failure detection and
auto switching for clock redundant applications. The generator uses a fully integrated PLL to generate clock signals from any one
of four redundant clock sources. The PLL multiplies the frequency of the input reference clock by one, two, four, eight or divides
the reference clock by two or four. The frequency-multiplied clock signal drives four banks of two differential outputs. Each bank
allows an individual frequency-divider configuration. All outputs are phase-aligned⁽¹⁾ to each other. Due to the external PLL
feedback, the clock signals of all outputs are also phase-aligned⁽¹⁾ to the selected input reference clock, providing virtually
zero-delay capability.
The integrated IDCS continuously monitors all four clock inputs and indicates a clock failure for each clock input. When a false
clock signal is detected on the active clock, the MPC9894 switches to a redundant clock input, forcing the PLL to slowly slew to
alignment and not produce any phase bumps at the outputs. The MPC9894 also provides a manual mode that allows for
user-controlled clock switches.
The device is packaged in a 11x11 mm² 100-ball MAPBGA package.
1. At coincident rising edges.
© Freescale Semiconductor, Inc., 2005. All rights reserved.