SY89846U

SY89846U 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 100mV). 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 100mV (200mVPP) without any level shifting or termination resistor networks in the signal path. The outputs are 800mV, 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: www.micrel.com. 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 ...