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Product Variant Information section
Product Specification Section
Pricing Section

Stock: 154

On Order: 0
Factory Stock:Factory Stock: 3,996
Factory Lead Time: 4 Weeks
Minimum Order: 1
Multiple Of: 1
Quantity Web Price
1 $15.95
5 $15.53
20 $14.92
50 $14.53
125+ $14.15


Attributes Table
Type Differential
Clock Input Frequency - Max 2.7GHz
Supply Voltage-Nom 3V to 3.6V
Features and Applications

The NB4N840M is a high−bandwidth fully differential dual 2 x 2 crosspoint switch with CML inputs/outputs that is suitable for applications such as SDH/SONET, DWDM, Gigabit Ethernet and high speed switching. Fully differential design techniques are used to minimize jitter accumulation, crosstalk, and signal skew, which make this device ideal for loop−through and protection channel switching applications.

Internally terminated differential CML inputs accept AC−coupled LVPECL (Positive ECL) or direct coupled CML signals. By providing internal 50 Ω input and output termination resistor, the need for external components is eliminated and interface reflections are minimized. Differential 16 mA CML outputs provide matching internal 50 Ω terminations, and 400 mV output swings when externally terminated, 50 Ω to VCC.

Single−ended LVCMOS/LVTTL SEL inputs control the routing of the signals through the crosspoint switch which makes this device configurable as 1:2 fan−out, repeater or 2 x 2 crosspoint switch. The device is housed in a low profile 5 x 5 mm 32−pin QFN package.

Key Features:

  • Plug−in compatible to the MAX3840 and SY55859L
  • Maximum Input Clock Frequency 2.7 GHz
  • Maximum Input Data Frequency 3.2 Gb/s
  • 225 ps Typical Propagation Delay
  • 80 ps Typical Rise and Fall Times
  • 7 ps Channel to Channel Skew
  • 430 mW Power Consumption
  • < 0.5 ps RMS Jitter
  • 7 ps Peak−to−Peak Data Dependent Jitter
  • Power Saving Feature with Disabled Outputs
  • Operating Range: VCC = 3.0 V to 3.6 V with VEE = 0 V
  • CML Output Level (400 mV Peak−to−Peak Output), Differential Output
  • These are Pb−Free Devices


  • OC-3 to OC-48 Line or System Loopback
  • Redundant Data Fan-out