Micrel MUX prevents runt pulses

The SY89845U precision CML runt pulse eliminator (RPE) 2:1 MUX from Micrel Semiconductor features a 1:2 fanout and internal termination. Unlike standard multiplexers, the company said, this new device prevents any short cycles or "runt" pulses during switchover.

The SY89845U also includes 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 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 outputs are 400mV CML with fast rise/fall times guaranteed to be less than 80ps.

Designed for redundant source switchover applications, the SY89845U operates from a 2.5V ±5 percent or 3.3V ±10 percent supply and is guaranteed over the full industrial temperature range of -40°C to 85°C.