advance information 1.8v, 500-mhz, 10-output jedec-complia nt zero delay buff er cy2sstu87 7 cypress semiconductor corporation ? 3901 north first street san jose , ca 95134 408-943-2600 document #: 38-07575 rev. ** revised august 21,2003 features ? operating frequency: 125 mhz to 500 mhz supports ddrii sdram ten differential outputs from one differential input spread-spectrum-compatible low jitter (cycle-to-cycle): < 40 ps very low skew: < 40 ps power management control input 1.8v operation fully jedec-jompliant 52-ball bga and a 40-pin mlf (qfn) functional description the CY2SSTU877 is a high-performance, low-skew, low-jitter zero delay buffer designed to distribute differential clocks in high-speed applications. the CY2SSTU877 generates ten differential pair clock outputs from one differential pair clock input. in addition, the CY2SSTU877 features differential feedback clock outputs and inputs. this allows the CY2SSTU877 to be used as a zero-delay buffer. when used as a zero-delay buffer in nested clock trees, the CY2SSTU877 locks onto the input reference and translates with near zero delay to low-skew outputs. this phase-locked loop (pll) clock buffer is designed for a vdd of 1.8v, an avdd of 1.8 v and differential data input and output levels. package options include a plastic 526-ball vfbga and a 40-pin mlf(qfn). the device is a zero delay buffer that distributes a differential clock input pair (ck, ck#) to ten differential pair of clock outputs (y[0:9], y#[0:9]) and one differential pair feedback clock outputs (fbout, fbout#). the input clocks (ck, ck#), the feedback clocks (fbin, fbin#), the lvcmos (oe, os), and the analog power input (avdd) control the clock outputs. the pll in the CY2SSTU877 clock driver uses the input clocks (ck, ck#) and the feedback clocks (fbin, fbin#) to provide high-performance, low-skew, low-jitter output differ- ential clocks (y[0:9], y#[0:9]). the CY2SSTU877 is also able to track spread spectrum clocking (ssc) for reduced emi. when avdd is grounded, the pll is turned off and bypassed for test purposes. when both clock signals (ck, ck#) are logic low, the device will enter a low power mode. an input logic detection circuit on the differential inputs, independent from the input buffers, will detect the logic low level and perform a low power state where all outputs, the feedback and the pll are off. when the inputs transition from both being logic low to being differential signals, the pll will be turned back on, the inputs and outputs will be enabled and the pll will obtain phase lock between the feedback clock pair (fbin, fbin#) and the input clock pair (ck, ck#) within the specified stabili- zation time tl.
advance information cy2sstu87 7 document #: 38-07575 rev. ** page 2 of 3 ? cypress semiconductor corporation, 2003. the information contained herein is subject to change without notice. cypress semico nductor corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a cypress semi conductor product. nor does it convey or imply any license unde r patent or other rights. cypress semiconductor does not authorize its products for use as critical components in life-support syst ems where a malfunction or failure may reasonably be expected t o result in significant injury to the user. the inclusion of cypress semiconductor products in life-support systems application implies th at the manufacturer assumes all risk of such use and in do ing so indemnifies cypress semiconductor against all charges. all product and company names mentioned in this document are the trademarks of their respective holders. block diagram pin configuration
advance information cy2sstu87 7 document #: 38-07575 rev. ** page 3 of 3 document history page document title:CY2SSTU877 1.8v, 500-mhz, 10-output jedec-compliant zero delay buffer document number: 38-07575 rev. ecn no. issue date orig. of change description of change ** 129198 08/22/03 rgl new data sheet
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