SY89837UMG-TR

Precision Edge PRECISION 1:8 LVPECL FANOUT SY89837U Micrel, Inc. Precision Edge BUFFER WITH 2:1 RUNT PULSE SY89837U ELIMINATOR INPUT MUX FEATURES Selects between two clocks, and provides 8 Precision Edge precision, low skew LVPECL output copies Guaranteed AC performance over temperature and DESCRIPTION supply voltage: Wide operating frequency: 1kHz to >1.5GHz The SY89837U is a low jitter, low skew, high-speed 1:8 <975ps in-to-out t pd fanout buffer with a unique, 2:1 differential input multiplexer <180ps t /t (MUX) optimized for clock redundant switchover applications. r f Unlike standard multiplexers, the SY89837U unique 2:1 runt <40ps output-to-output skew pulse eliminator (RPE) input MUX prevents any short cycles Unique input isolation design minimizes crosstalk or runt pulses during switchover. In addition, a unique Ultra-low jitter design: fail-safe input protection prevents metastable conditions 150fs RMS phase jitter when the selected input clock fails to a static DC differential voltage (differential input voltage drops below 200mV). <0.7ps MUX crosstalk induced jitter rms The SY89837U distributes clock frequencies from 1kHz to Unique input termination and VT pin accepts DC- or 1.5GHz, guaranteed, over temperature and voltage. AC-coupled inputs (CML, PECL, LVDS) The differential input includes Micrels unique, 3-pin input 800mV LVPECL output swing termination architecture that allows customers to interface Power supply +2.5V 5% or +3.3V 10% to any differential signal (AC- or DC-coupled) as small as 40C to +85C industrial temperature range 200mV without any level shifting or termination resistor networks in the signal path. The outputs are 800mV, 100k Available in 32-pin (5mm x 5mm) QFN package compatible LVPECL with fast rise/fall times guaranteed to be less than 200ps. The SY89837U operates from a +2.5V 5% or +3.3V 10% supply and is guaranteed over the full industrial temperature range of 40C to +85C. The SY89837U is part of Micrels high-speed, Precision Edge product line. APPLICATIONS All support documentation can be found on Micrels web site at: www.micrel.com. Redundant clock distribution Fail-safe clock protection Precision Edge is a registered trademark of Micrel, Inc. Rev.: F Amendment: /0 M9999-060410 1 Issue Date: June 2010 hbwhelp micrel.com or (408) 955-1690 Precision Edge SY89837U Micrel, Inc. TYPICAL APPLICATIONS CIRCUIT Figure 1. Simplied Example Illustrating Runt Pulse Eliminator (RPE) Circuit When Primary Clock Fails TRUTH TABLE Inputs Outputs IN0 /IN0 IN1 /IN1 SEL Q /Q 0 1 X X 0 0 1 1 0 X X 0 1 0 X X 0 1 1 0 1 X X 1 0 1 1 0 M9999-060410 2 hbwhelp micrel.com or (408) 955-1690