SY89846U Datasheet | Micrel Semiconductor

1.5GHz Precision, LVPECL 1:5 Fanout with 2:1 MUX and Fail Safe Input with Internal Termination Precision Edge® General Description The SY89846U is a 2.5/3.3V, 1:5 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 (voltage between the pins of the differential input drops significantly below 100m V). The differential input includes Micrel’s unique, 3-pin internal termination architecture that can interface to any differential signal (AC- or DC-coupled) as small as 100m V (200m VPP) without any level shifting or termination resistor networks in the signal path. The outputs are 800m V, LVPECL with fast rise/fall times guaranteed to be less than 250ps. The SY89846U operates from a 2.5V ±5% or 3.3V ±10% supply and is guaranteed over the full industrial temperature range of - 40°C to +85°C. The SY89846U is part of Micrel’s high-speed, Precision Edge® product line. All support documentation can be found on Micrel’s web site at: .micrel.. Functional Block Diagram Features Precision Edge® - Selects between two inputs, and provides 5 precision LVPECL copies - Fail-Safe Input - Prevents outputs from oscillating when input is invalid - Guaranteed AC performance over temperature and supply voltage: - DC-to >1.5GHz throughput - < 900ps Propagation Delay (IN-to-Q) - < 250ps Rise/Fall times - Ultra-low jitter design: - 150fs RMS phase jitter (Typ) - 0.7ps RMS 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 3.3 ±10% supply voltage - -40°C to +85°C industrial temperature range - Available in 32-pin (5mm x 5mm) QFN package Applications - Fail-safe clock protection - SONET clock distribution - Backplane...