SY89837U

Micrel, Inc. PRECISION 1:8 LVPECL FANOUT BUFFER WITH 2:1 RUNT PULSE ELIMINATOR INPUT MUX Precision Edge® Precision ESdY8g9e8®37U SY89837U FEATURES ■ Selects between two clocks, and provides 8 precision, low skew LVPECL output copies ■ Guaranteed AC performance over temperature and supply voltage: ■ Wide operating frequency: 1kHz to >1.5GHz <975ps in-to-out tpd <180ps tr/tf <40ps output-to-output skew ■ Unique input isolation design minimizes crosstalk ■ Ultra-low jitter design: 150fs RMS phase jitter <0.7psrms MUX crosstalk induced jitter ■ Unique input termination and VT pin accepts DC- or AC-coupled inputs (CML, PECL, LVDS) ■ 800mV LVPECL output swing ■ Power supply +2.5V ±5% or +3.3V ±10% ■ –40°C to +85°C industrial temperature range ■ Available in 32-pin (5mm x 5mm) QFN package APPLICATIONS ■ Redundant clock distribution ■ Fail-safe clock protection Precision Edge® DESCRIPTION The SY89837U is a low jitter, low skew, high-speed 1:8 fanout buffer with a unique, 2:1 differential input multiplexer (MUX) optimized for clock redundant switchover applications. Unlike standard multiplexers, the SY89837U unique 2:1 runt pulse eliminator (RPE) input MUX prevents any short cycles or “runt” pulses during switchover. In addition, a unique fail-safe input protection prevents metastable conditions when the selected input clock fails to a static DC differential voltage (differential input voltage drops below 200mV). The SY89837U distributes clock frequencies from 1kHz to 1....