11.32Gbps Transceiver with Dual CDRs, Digital Monitors, and DC-Coupled Laser Driver

Enables 1W SFP+ Sonet OC-192 Applications

Please check latest availability status for a specific part variant.


The MAX3955 is an 11.3Gbps, highly-integrated, low-power transceiver with dual CDRs, and digital diagnostics monitoring (DDM) designed for next-generation SONET transmission systems. The receiver incorporates a limiting amplifier with loss-of-signal (LOS) circuit. The limiting amplifier features an independent 9.95Gbps to 11.32Gbps CDR. The transmitter incorporates Maxim’s proprietary DC-coupled laser driver interface, an independent 9.95Gbps to 11.32Gbps CDR, and closed-loop control of average laser power.

The MAX3955 supports differential AC-coupled signaling with integrated 50Ω terminations at Rx input, Rx output, and Tx input. The Tx output is a DC-coupled 25Ω laser diode interface with dedicated pins for the laser anode (TOUTA) and the laser cathode (TOUTC).

An integrated 12-bit analog-to-digital converter (ADC) is utilized to provide digital monitors of internal/external temperature, VCC, and received signal strength indication (RSSI). The MAX3955’s analog monitors and the use of a 2-wire or 3-wire slave interface enables configuration through either a digital-only microcontroller (µC) or through the DS1978 SFP+ controller (future product).

The MAX3955 operates from single +3.3V supply and over a -40°C to +95°C temperature range and is available in a standard 5mm x 5mm, 32-pin TQFN-EP package.

MAX3955: Simplified Block Diagram MAX3955: Simplified Block Diagram Enlarge+

Key Features

    • Dual CDRs Exceeding SONET Jitter Requirements with PLL Bandwidth Setting of 7MHz
    • 540mW Typical IC Power Dissipation (ILD_MOD = 45mA, IBIAS = 45mA, Both CDRs Enabled)
    • Independent, Reference-less Tx and Rx CDRs
    • Pattern Generator for Receive and Transmit Paths
    • Signal Loop-Back Paths
    • Programmable Tx Input Equalization and Rx Output Deemphasis
    • Pin-Compatible with MAX3956 11.3Gbps Transceiver
    Safety and Monitoring
    • Integrated Eye Safety Features with Maskable Fault and Interrupt Signal Generation
    • Analog Monitors with Integrated 12-Bit ADC, Fully Supporting SFF-8472 DDM with Digital-Only µC
    • High-Accuracy Temperature, VCC, and RSSI Monitors
    • Auxiliary ADC Input at BADC for General Use


  • OC-192 XFP and SFP+ Optical Transceivers
Part NumberApplicationsTarget Oper. Range
Data Rate
Data Rate
Package/PinsOper. Temp.
minmaxtypmaxmaxSee Notes
10G Ethernet
Fibre Channel
1.25 to 11.39950113003.3165CML85100
-40 to +95$13.13 @1k
See All Optical Transceivers (7)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

App Note 5888 Recommended Initialization Sequence for the MAX3955 and MAX3956 Devices

Quality and Environmental Data

Product Reliability Reports: MAX3955.pdf 
Lead-Free Package Tin (Sn) Whisker Reports
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources