SY89838U

SY89838U Precision 1:8 LVDS Clock Fanout Buffer with 2:1 Runt Pulse Eliminator Input MUX General Description The SY89838U is a low jitter, low skew, high-speed 1:8 fanout buffer with a unique, 2:1 differential input multiplexer (MUX) optimized for redundant source switchover applications. Unlike standard multiplexers, the SY89838U unique 2:1 Runt Pulse Eliminator (RPE) 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 DC voltage (voltage between the pins of the differential input drops below 200mV). The SY89838U distributes clock frequencies from 1kHz to 1.5GHz, guaranteed, over temperature and voltage. The differential input includes Micrel’s unique, 3-pin input termination architecture that allows customers to interface to any differential signal (AC- or DC-coupled) as small as 200mV (400MvPP) without any level shifting or termination resistor networks in the signal path. The outputs are 350mV compatible LVDS with fast rise/fall times guaranteed to be less than 150ps. The SY89838U operates from a 2.5V ±5% supply and is guaranteed over the full industrial temperature range of –40°C to +85°C. For applications that require 800mV LVPECL outputs, consider the SY89837U. The SY89838U 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. Features Precision E...