General Description

The SY89467U is a 2.5/3.3V, 1:20 LVPECL fanout buffer with a 2:1 differential input multiplexer (MUX). A unique Fail-Safe Input (FSI) protection prevents metastable output conditions when the selected input clock fails to a DC voltage (when voltage between the pins of the differential input drops significantly below 100mV).

Features

• Selects between two inputs, and provides 20 precision LVPECL copies

• Fail-Safe Input

– Prevents outputs from oscillating when input is invalid

• Guaranteed AC performance over temperature and supply voltage:

– DC-to >1.5 GHz throughput

– < 1200ps Propagation Delay (In-to-Q)

– 270ps Rise/Fall times

• Ultra-low jitter design:

– <1psRMS random jitter

– <1psRMS cycle-to-cycle jitter

– <10psPP total jitter (clock)

– <0.7psRMS MUX crosstalk induced jitter

• Unique, patented MUX input isolation design minimizes adjacent channel crosstalk

• Unique patented internal termination and VT pin accepts DC- and AC-coupled inputs (CML, PECL, LVDS)

• Wide input voltage range: VCC to GND

• 2.5V ±5 or 3.3V ±10 supply voltage

• -40°C to +85°C industrial temperature range

• Available in 64-pin TQFP package

Applications

• Fail-safe clock protection

• SONET clock distribution

• Backplane distribution