CDCVF857

2.5V PHASELOCK LOOP CLOCK DRIVER

SCAS047D − MARCH 2003 − REVISED JUNE 2005

1

POST OFFICE BOX 655303

− DDR Memory Modules

(DDR400/333/266/200)

− Zero Delay Fan-Out Buffer

(SSTL2)

TSSOP Package, 56-Ball MicroStar Junior



BGA Package

Used to Synchronize the Outputs to the

Input Clocks

(JESD82−1) For DDRI-200/266/333

Specification

Specification (JESD82−1A)

Input Signal Is Applied or PWRDWN Is Low

description

The CDCVF857 is a high-performance, low-skew, low-jitter, zero-delay buffer that distributes a differential clock

input pair (CLK, CLK) to 10 differential pairs of clock outputs (Y[0:9], Y[0:9]) and one differential pair of feedback

clock outputs (FBOUT, FBOUT). The clock outputs are controlled by the clock inputs (CLK, CLK), the feedback

and frequency with CLK. When PWRDWN is low, all outputs are disabled to a high-impedance state (3-state)

and the PLL is shut down (low-power mode). The device also enters this low-power mode when the input

frequency falls below a suggested detection frequency that is below 20 MHz (typical 10 MHz). An input

frequency detection circuit detects the low frequency condition and, after applying a >20-MHz input signal, this

detection circuit turns the PLL on and enables the outputs.

to track spread spectrum clocking for reduced EMI.

Because the CDCVF857 is based on PLL circuitry, it requires a stabilization time to achieve phase-lock of the

PLL. This stabilization time is required following power up. The CDCVF857 is characterized for both commercial

and industrial temperature ranges.

AVAILABLE OPTIONS

TA

TSSOP (DGG)

40-Pin MLF

56-Ball BGA †

−40

°C to 85°C

CDCVF857DGG

(Pb-Free)

CDCVF857RTB

CDCVF857GQL

−40

°C to 85°C

CDCVF857RHA

(Pb-Free, Green)

† Maximum load recommended is 12 pf for 200 MHz. At 12-pf load, maximum TA allowed is 70°C.

Copyright

 2005, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.