SY89112U 2.5/3.3V Low-Jitter, Low-Skew 1:12 LVPECL Fanout Buffer with 2:1 Input MUX and Internal Termination General Description Features The SY89112U is a low-jitter, low-skew, high-speed Selects between 1 of 2 inputs, and provides 12 LVPECL 1:12 differential fanout buffer optimized for precision, low skew LVPECL output copies precision telecom and enterprise server distribution Guaranteed AC performance over temperature and applications. The input includes a 2:1 MUX for clock voltage: switchover application. Unlike other multiplexers, this input DC to >2GHz throughput includes a unique isolation design to minimize channel-to- <550ps propagation delay CLK-to-Q channel crosstalk. The SY89112U distributes clock frequencies from DC to >2GHz guaranteed over <220ps rise/fall time temperature and voltage. The SY89112U incorporates a <25ps output-to-output skew synchronous output enable (EN) so that the outputs will Ultra-low jitter design: only be enabled/disabled when they are already in the 50fs phase jitter (typ.) RMS LOW state. This reduces the chance of generating runt clock pulses. <0.7ps crosstalk induced jitter RMS Unique, patent-pending input termination and VT pin The SY89112U differential input includes Micrels unique, accepts DC-coupled and AC-coupled differential inputs patent-pending 3-pin input termination architecture that Unique, patent-pending 2:1 input MUX provides superior directly interfaces to any differential signal (AC- or DC- isolation to minimize channel-to-channel crosstalk coupled) as small as 100mV (200mV ) without any level pp shifting or termination resistor networks in the signal path. 800mV, 100K LVPECL output swing For AC-coupled input interface, an on-board output Power supply 2.5V +5% or 3.3V +10% reference voltage (VREF-AC) is provided to bias the Industrial temperature range 40C to +85C center-tap (VT) pin. The outputs are 800mV, 100K- Available in 44-pin (7mm x 7mm) QFN package compatible LVPECL with fast rise/fall times guaranteed to be less than 220ps. Applications The SY89112U operates from a 2.5V 5% or 3.3V 10% Multi-processor server supply and is guaranteed over the full industrial temperature range of 40C to +85C. The SY89112U is SONET/SDH clock/data distribution part of Micrels high-speed, Precision Edge product line. Fibre Channel distribution Datasheets and support documentation are available on Gigabit Ethernet clock distribution Micrels web site at: www.micrel.com. United States Patent No. RE44,134 Precision Edge is a registered trademark of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. SY89112U Functional Block Diagram 040814-6.0 April 8, 2014 2 hbwhelp micrel.com or (408) 955-1690