INCUA845
DDR2 - 1:5 Zero Delay Clock Buffer

Applications

• DDR2-400, 533, 667, and 800 Registered and Clocked DIMMs
• High Performance Workstations
• Mid and High Performance Servers
• Telecommunications Memory Applications

Features

• Operates with 200, 266, 333 and 400 MHz clocks 
• Exceeds all JESD82-xx performance specifications for the CUA845 at all DDR2 rates
• Available in a 28 Ball VFBGA leaded, “Green” Package
• Latch up exceeds JESD78 class 2
• ESD protection exceeds JESD22
• Passed Intel Validation

Description

The INCU845 is a high performance, low skew, PLL-based, zero delay buffer that distributes a differential input clock signal to five differential clock outputs and one differential feedback clock output. 

The clock outputs are controlled by the input clock, the input feedback (reference) clock, the LVCMOS control inputs, and the analog power supply.

When the Output Enable (OE) input is low, all outputs, except the differential feedback clock outputs, are disabled while the internal PLL continues to maintain frequency lock.   The Output Select (OS) is a program pin that must be tied to GND or V_DDQ.  When the OS is high, OE will function as described above.  When OS is low, OE will remain enabled.  When AV_DD is grounded, the PLL is turned off and bypassed for test purposes.  When both clock input pins are logic low, the device enters a low power mode.  A logic circuit on the clock input pins, independent from the input buffers, detects the logic low levels and places the part in a low power state where all the outputs and the PLL are off.  When the inputs transition from being both logic low to being a differential signal, the PLL is turned back on, the inputs and outpus are enabled, and the PLL obtains phase lock between the input feedback clock pair and the input clock pair, within the specified stabilization time.

The INCU845 is also able to track Spread Spectrum Clocking (SSC) for reduced EMI.

The INCUA845 is designed for nominal 1.8 V power supply operation and is packaged in a plastic 28-ball VFBGA package.

For more information about the INCUA845 or other Inphi products, please click here and enter your email address for product downloads. New users must first complete our product request form.

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