SY89843U
Precision LVPECL Runt Pulse Eliminator 2:1
MUX with 1:2 Fanout and Internal Termination General Description
The SY89843U is a low jitter PECL, 2:1 differential input
multiplexer (MUX) optimized for redundant source
switchover applications. Unlike standard multiplexers,
the SY89843U 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
100mV).
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 100mV (200mVPP) without any level shifting
or termination resistor networks in the signal path. The
output is 800mV, 100K compatible LVPECL with fast
rise/fall times guaranteed to be less than 190ps.
The SY89843U operates from a 2.5V В±5% or 3.3V
В±10% supply and is guaranteed over the full industrial
temperature range of –40В°C to +85В°C. The SY89843U is …