SY89840UMG-TR Microchip

SY89840U Precision LVPECL Runt Pulse Eliminator 2:1 Multiplexer General Description The SY89840U is a low jitter PECL, 2:1 differential input Precision Edge multiplexer (MUX) optimized for redundant source Features switchover applications. Unlike standard multiplexers, the SY89840U unique 2:1 Runt Pulse Eliminator (RPE) Selects between two sources, and provides a glitch-free, MUX prevents any short cycles or runt pulses during stable LVPECL output switchover. In addition, a unique Fail-Safe Input Guaranteed AC performance over temperature and supply protection prevents metastable conditions when the voltage: selected input clock fails to a DC voltage (voltage Wide operating frequency: 1kHz to >1.5GHz between the pins of the differential input drops below < 880ps In-to-Out t pd 100mV). < 190ps t /t r f The differential input includes Micrels unique, 3-pin Unique patent-pending input isolation design minimizes input termination architecture that allows customers to crosstalk interface to any differential signal (AC or DC-coupled) as Fail-safe input prevents oscillations small as 100mV (200mV ) without any level shifting or pp Ultra-low jitter design: termination resistor networks in the signal path. The 140fs RMS phase jitter (Typ) output is 800mV, 100K compatible LVPECL with fast 0.7ps MUX crosstalk induced jitter rms rise/fall times guaranteed to be less than 190ps. Unique patent-pending input termination and VT pin The SY89840U operates from a 2.5V 5% or 3.3V accepts DC-coupled and AC-coupled inputs (CML, 10% supply and is guaranteed over the full industrial PECL, LVDS) temperature range of 40C to +85C. The SY89840U is 800mV LVPECL output swing 2.5V 5% or 3.3V 10% supply voltage part of Micrels high-speed, Precision Edge product 40C to +85C industrial temperature range line. All support documentation can be found on Micrels web site at: www.micrel.com. Available in 16-pin (3mm x 3mm) QFN package Applications Redundant clock switchover Failsafe clock protection Markets LAN/WAN Enterprise servers ATE Test and measurement 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. SY89840U Typical Application Simplified Example Illustrating RPE (Runt Pulse Elimination) Circuit when Primary Clock Fails 2 M9999-021705 Oct. 1, 2013 hbwhelp micrel.com or (408) 955-1690