EVALUATION KIT AVAILABLE MAX3948 11.3Gbps, Low-Power, DC-Coupled Laser Driver General Description Benefits and Features The MAX3948 is a 3.3V, multirate, low-power laser diode S Lowest Power Consumption driver designed for Ethernet, Fibre Channel, and SONET 168mW Typical IC Power Dissipation at 3.3V transmission systems at data rates up to 11.3Gbps. This (LD = 40mA, LD = 20mA) MOD DC device is optimized to drive a differential transmitter 383mW Total Transmitter Power Dissipation at optical subassembly (TOSA) with a 25I flex circuit. The 3.3V Including LD = 40mA, LD = 20mA MOD DC unique design of the output stage enables DC-coupling Enables < 1W Maximum Total SFP+ Module to unmatched TOSAs, thereby lowering transmitter power Power Dissipation consumption by more than 100mW. Enables < 2.5W Maximum Total QSFP+ Module Power Dissipation The MAX3948 receives differential AC-coupled signals with on-chip termination. It can deliver laser modula- S Saves Board Space tion currents of up to 85mA at an edge speed of 26ps Small 3mm x 3mm Package (20% to 80%) into a 5I external differential load. The DC-Coupling to the Laser Reduces External Component Count device is designed to have a high-bandwidth differen- tial signal path with on-chip back termination resistors S Flexibility integrated into its outputs. An input equalization block Operate Up to Four MAX3948 ICs Over Single can be activated to compensate for SFP+/QSFP+ host 3-Wire Digital Interface connector losses. The integrated DC circuit provides Programmable Modulation Current Up to programmable laser DC currents up to 61mA. Both the 85mA (5 Load) laser DC current generator and the laser modulator can Programmable DC Current Up to 61mA be disabled from a single pin. (Translates to Up to 100mA Laser Bias Current) The device offers one dedicated pin (VSEL) to program up Programmable Input Equalization and Output to four channel addresses for multichannel applications. Deemphasis The use of a 3-wire digital interface reduces the pin count S Safety while permitting adjustment of input equalization, polar- Supports SFF-8431 SFP+ MSA and SFF-8472 ity, output deemphasis, and modulation and DC currents Digital Diagnostic without the need for external components. The MAX3948 Integrated Eye Safety Features with Maskable is available in a 3mm x 3mm, 16-pin TQFN package, and Faults is specified for the -40NC to +95NC extended temperature DC Current Monitor range. Applications 40GBASE-LR4 QSFP+ Optical Transceivers Ordering Information appears at end of data sheet. 10GBASE-LR SFP+ Optical Transceivers 10GBASE-LRM SFP+ Optical Transceivers OC192-SR SFP+ SDH/SONET Transceivers For pricing, delivery, and ordering information, please contact Maxim Direct at 19-5943 Rev 1 6/12 1-888-629-4642, or visit Maxim Integrateds website at www.maximintegrated.com.MAX3948 11.3Gbps, Low-Power, DC-Coupled Laser Driver ABSOLUTE MAXIMUM RATINGS V , V ............................................................-0.3V to +4.0V Current into TOUTC and TOUTA .................................. +150mA CC CCT V - V ..................................................................... < 0.5V Continuous Power Dissipation (T = +70NC) CC CCT A Voltage Range at TIN+, TIN-, DISABLE, TQFN (derate 20.8mW/NC above +70NC)...............1666.7mW SDA, SCL, CSEL, VSEL, FAULT, and BMON ......-0.3V to V Storage Temperature Range .......................... -55NC to +150NC CC Voltage Range at VOUT and TOUTC .......0.4V to (V - 0.4V) Die Attach Temperature .................................................+400NC CCT Voltage Range at TOUTA ...........(V - 1.3V) to (V + 1.3V) Lead Temperature (soldering, 10s) ................................+300NC CCT CCT Current Range into TIN+ and TIN- .................. -20mA to +20mA Soldering Temperature (reflow) ......................................+260NC Current Range into VOUT ................................. -2mA to +90mA Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional opera- tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. PACKAGE THERMAL CHARACTERISTICS (Note 1) TQFN Junction-to-Ambient Thermal Resistance (B ) ..........48NC/W JA Junction-to-Case Thermal Resistance (B ) ...............10NC/W JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. ELECTRICAL CHARACTERISTICS (V = V = 2.95V to 3.63V, T = -40NC to +95NC typical values are at V = V = 3.3V, T = +25NC, LD = 20mA, LD CC CCT A CC CCT A DC MOD = 40mA, and 14I single-ended electrical output load, unless otherwise noted. See Figure 1 for electrical setup.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Excludes output current through the exter- Power-Supply Current I 51 62 mA CC nal pullup inductors (Note 3) Power-Supply Voltage V , V 2.95 3.63 V CCT CC POWER-ON RESET V for Enable High 2.55 2.75 V CC V for Enable Low 2.3 2.45 V CC DATA INPUT SPECIFICATION Input Data Rate 1 10.3 11.3 Gbps Launch amplitude into FR4 transmission line P 12in, 0.2 0.8 SET TXEQ 1:0 = 01b, SET TXEQ 1:0 = 11b Differential Input Voltage V V IN P-P SET TXEQ 1:0 = 01b, SET TXEQ 1:0 = 11b, 0.15 1.0 outside of optimized range SET TXEQ 1:0 = 00b 0.15 1.0 Common-Mode Input Voltage V 2.15 V CM Differential Input Resistance R 75 100 125 I IN Maxim Integrated 2