FEATURES:

• 1 to 10 differential clock distribution

• Optimized for clock distribution in DDR2 (Double Data Rate)

SDRAM applications

• Operating frequency: 125MHz to 340MHz

• Very low skew: ≤40ps

• Very low jitter: ≤40ps

• 1.8V AVDD and 1.8V VDDQ

• CMOS control signal input

• Test mode enables buffers while disabling PLL

• Low current power-down mode

• Tolerant of Spread Spectrum input clock

• Available in 52-Ball VFBGA and 40-pin VFQFPN packages

DESCRIPTION:

The CSPU877A is a PLL based clock driver that acts as a zero delay buffer

to distribute one differential clock input pair(CLK, CLK ) to 10 differential

output pairs (Y [0:9], Y [0:9]) and one differential pair of feedback clock output

(FBOUT, FBOUT). External feedback pins (FBIN, FBIN) for synchronization

of the outputs to the input reference is provided. OE, OS, and AVDD control the

power-down and test mode logic. When AVDD is grounded, the PLL is turned

off and bypassed for test mode purposes. When the differential clock inputs

(CLK, CLK) are both at logic low, this device will enter a low power-down mode.

In this mode, the receivers are disabled, the PLL is turned off, and the output

clock drivers are disabled, resulting in a current consumption device of less than

500μA.

The CSPU877A requires no external components and has been optimised

for very low phase error, skew, and jitter, while maintaining frequency and duty

cycle over the operating voltage and temperature range. The CSPU877A,

designed for use in both module assemblies and system motherboard based

solutions, provides an optimum high-performance clock source.

The CSPU877A is available in Commercial Temperature Range (0°C to

+70°C). See Ordering Information for details.