MAX3945 19-5144 Rev 0 2/10 1.0625Gbps to 11.3Gbps, SFP+ Dual-Path Limiting Amplifier General Description Features The MAX3945 is a +3.3V, multirate, low-power limiting S 130mW Power Dissipation Enables < 1W SFP+ amplifier optimized for Fibre Channel and Ethernet trans- Modules mission systems at data rates up to 11.3Gbps. The high- S Enables Single-Module Design Compliance sensitivity limiting amplifier limits the signal generated by with 1000BASE-SX/LX and 10GBASE-SR/LR a transimpedance amplifier into a CML-level differential Specifications output signal. All differential inputs and outputs (I/O) are S -25.3dBm Optical Sensitivity at 1.25Gbps Using a optimally back terminated for 50I transmission line PCB 10.32Gbps ROSA design. The MAX3945s dual-path limiting amplifier has S Selectable 1GHz/2.1GHz/2.5GHz/3GHz Input Filters programmable filtering to optimize sensitivity for differ- ent data rates and to suppress relaxation oscillations at RATE SEL = 0 Setting that could occur in some optical systems. The MAX3945 S Supports SFF-8431 SFP+ MSA and SFF-8472 incorporates two loss-of-signal (LOS) circuits and a pro- Digital Diagnostic grammable time mask for the LOS output. S Total Power Dissipation of 130mW at 3.3V Power A 3-wire digital interface reduces the pin count and Supply with RSSI Monitor-Based LOS enables control of LOS threshold, LOS polarity, LOS S Total Power Dissipation of 154mW at 3.3V Power mode, CML output level, input offset correction, receive Supply with Rx Input-Based LOS (Rx) polarity, Rx input filter, and Rx deemphasis without S 4mV Input Sensitivity at 11.3Gbps the need for external components. P-P S 4ps DJ at 11.3Gbps with RATE SEL = 1 The MAX3945 is packaged in a 3mm x 3mm, 16-pin P-P TQFN package. S 4ps DJ at 8.5Gbps with RATE SEL = 1 P-P S 5ps DJ at 4.25Gbps with RATE SEL = 0, P-P Applications BW1 = 1, BW0 = 1 1x/2x/4x/8x SFF/SFP/SFP+ MSA Fibre-Channel S 9.0ps DJ at 1.25Gbps with RATE SEL = 0, P-P Optical Transceiver BW1 = 0, BW0 = 0 10GBASE-SR/LR SFP+ Optical Transceiver S 26ps Rise and Fall Time with RATE SEL = 1 10G PON ONU S 52ps Rise and Fall Time with RATE SEL = 0 Ordering Information S CML Output with Level Adjustment and Squelch Mode PART TEMP RANGE PIN-PACKAGE S Programmable CML Output Deemphasis MAX3945ETE+ 16 TQFN-EP* -40NC to +85NC S CML Output Polarity Select +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. S LOS Polarity Select S Programmable Masking Time for the LOS Output S LOS Assert/Deassert Level Adjustment Typical Application Circuit appears at end of data sheet. S Choice of Rx Input-Based LOS or RSSI Monitor- Based LOS S 3-Wire Digital Interface Compatible with Maxims SFP+ Family of Products Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE1.0625Gbps to 11.3Gbps, SFP+ Dual-Path Limiting Amplifier ABSOLUTE MAXIMUM RATINGS V .......................................................................-0.3V to +4.0V Current Out of ROUT+, ROUT- ..........................................40mA CC Voltage Range at SDA, SCL, CSEL, Continuous Power Dissipation (T = +70NC) A LOS, CAZ, RPMIN ................................. -0.3V to (V + 0.3V) 16-Pin TQFN (derate 14.7mW/NC above +70NC) .........1.176W CC Voltage Range at ROUT+, ROUT- ........(V - 2V) to (V + 0.3V) Operating Junction Temperature Range ......... -55NC to +150NC CC CC Voltage Range at RIN+, RIN- ........ (V - 1.7V) to (V + 0.3V) Storage Temperature Range ............................ -65NC to +160NC CC CC Current Range Into LOS ...................................... -1mA to +5mA Lead Temperature (soldering, 10s) ................................+300NC Current Range Into SDA ..................................... -1mA to +1mA Soldering Temperature (reflow) ......................................+260NC Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation 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. ELECTRICAL CHARACTERISTICS (V = 2.85V to 3.63V, CML receiver output is AC-coupled to differential 100I load, C = 0.1FF, T = -40NC to +85NC. Registers CC CAZ A are set to default values, unless otherwise noted. Typical values are at V = 3.3V, T = +25NC, unless otherwise noted.) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Includes the CML output current, V = 400mV , RXDE EN = 0, 46.6 62 DIFF ROUT P-P LOS1 EN = 1, LOS2 EN = 0 Power-Supply Current I mA CC Includes the CML output current, V = 400mV , RXDE EN = 0, 39.4 52.5 DIFF ROUT P-P LOS1 EN = 0, LOS2 EN = 1 Power-Supply Voltage V 2.85 3.63 V CC f < 10MHz 100 Power-Supply Noise mV P-P 10MHz < f < 20MHz 10 GENERAL Input Data Rate 1.06 10.32 11.3 Gbps Input/Output SNR 14.1 BER 10E-12 POWER-ON RESET (POR) POR Deassert Threshold 2.55 2.75 V POR Assert Threshold 2.3 2.45 V INPUT SPECIFICATIONS Differential Input Resistance R 75 100 125 I IN DIFF RIN+/RIN- RATE SEL = 1, input transition time 25ps, 4 8 10.32Gbps, PRBS23-1 pattern Input Sensitivity V mV INMIN P-P (Note 1) RATE SEL = 0, input transition time 260ps, 1 2 1.25Gbps, K28.5 pattern Input Overload V 1.2 V INMAX P-P DUT is powered on, f P 5GHz 10 SDD11 dB DUT is powered on, f P 16GHz 7 Input Return Loss DUT is powered on, 1GHz < f P 5GHz 13 SCC11 dB DUT is powered on, 1GHz < f P 16GHz 5 LOS1 EN = 0 and LOS2 EN = 1, RPMIN Input-Current High I 50 nA IH V = 2V RPMIN 2 MAX3945