Four channel 25G / 28G CDR with integrated input equalizer

The M37049 is a four channel 25G / 28G CDR with input equalizer for use as a transmit device in optical modules and Active Optical Cables (AOC). The M37049 CDRs retime at 25.78 Gbps for 100GbE and EDR Infiniband, 27.95 Gbps for OTU4, and 28.05 Gbps for 32G Fiber Channel applications. Each channel includes adaptive input equalization, a high performance CDR, and an output driver with programmable output swing and de-emphasis. The CDR is reference-free and can be bypassed to support legacy or non-standard data rates. The M37049 is available in a 4 mm x 4.5 mm chip scale package (CSP) and integrates diagnostic features such as PRBS9/31 pattern generator and PRBS31 error detector. The device is powered from a single 1.8V supply delivering industry’s leading low power consumption. The device is controlled through a 2-wire serial interface.

Product Specifications

Part Number
Short Description
Four channel 25G / 28G CDR with integrated input equalizer
Max Data Rate(Gbps)
Number of Channels
Package Type
Integrated CDR


  • Quad 25.78 Gbps/28.05 Gbps CDR
  • Extracted clock output Fb/2, Fb/8, Fb/32 or Fb/40 (Monitor Clock)
  • Supports -40 °C to +85 °C case temperature
  • Low output jitter
  • High input jitter tolerance
  • Low power
  • Reference-free CDR
  • Adaptive input equalization with optional programmable
  • Programmable LOS threshold
  • Programmable output de-emphasis
  • Programmable output swing
  • Integrated PRBS Generator and Checker


  • 100-Gigabit Ethernet 100GbE
  • 100G OTN (OTU-4)
  • Active Optical Cables
  • Fiber Channel 32GFC, 128GFC
  • InfiniBand EDR
  • Onboard optical engines
  • Optical Modules
  • Optical Modules CFP-2, CFP-4, QSFP+

Technical Resources

Data Sheet

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Four channel 25G / 28G CDR with integrated input equalizer