MAX3740A 19-3118 Rev 3 1/10 3.2Gbps SFP VCSEL Driver with Diagnostic Monitors General Description Features The MAX3740A is a high-speed VCSEL driver for small- Supports all SFF-8472 Digital Diagnostics form-factor (SFF) and small-form-factor pluggable (SFP) 2mA to 15mA Modulation Current fiber optic LAN transmitters. It contains a bias genera- tor, a laser modulator, and comprehensive safety fea- 1mA to 15mA Bias Current tures. The automatic power control (APC) adjusts the Optional Peaking Current to Improve VCSEL Edge laser bias current to maintain average optical power Speed over changes in temperature and laser properties. The driver accommodates common cathode and differential Supports Common Cathode and Differential configurations. Configuration The MAX3740A operates up to 3.2Gbps. It can switch Automatic Power Control up to 15mA of laser modulation current and source up to 15mA of bias current. Adjustable temperature com- Safety Circuits Compliant with SFF and SFP pensation is provided to keep the optical extinction MSAs ratio within specifications over the operating tempera- 4mm 4mm, 24-Pin Thin QFN Package ture range. The MAX3740A interfaces with the Dallas DS1858 to meet SFF-8472 timing and diagnostic requirements. The MAX3740A accommodates various Ordering Information VCSEL packages, including low-cost TO-46 headers. The MAX3740A safety circuit detects faults that could PART TEMP RANGE PIN-PACKAGE cause hazardous light levels and disables the VCSEL MAX3740AETG -40C to +85C 24 Thin QFN-EP* output. The safety circuits are compliant with SFF and MAX3740AETG+ -40C to +85C 24 Thin QFN-EP* SFP multisource agreements (MSA). +Denotes a lead(Pb)-free/RoHS-compliant package. The MAX3740A is available in a compact 4mm 4mm, *EP = Exposed pad. 24-pin thin QFN package and operates over the -40C to +85C temperature range. Applications Typical Application Circuit Multirate (1Gbps to 3.2Gbps) SFP/SFF Modules +3.3V Gigabit Ethernet Optical Transmitters 4.7k V CC Fibre Channel Optical Transmitters FAULT PWRMON Infiniband Optical Transmitters MODSET TX DISABLE R MODSET SQUELCH REF MAX3740A 0.1F IN+ COMP R PWRSET 0.047F MD IN- 0.1F BIAS TC1 R TC L1* 0.01F TC2 OUT+ C BIASSET F OUT- R BIASSET 0.01F GND PEAKSET BIASMON R 50 F R PEAKSET R BIASMON OPTIONAL COMPONENT *FERRITE BEAD 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.3.2Gbps SFP VCSEL Driver with Diagnostic Monitors ABSOLUTE MAXIMUM RATINGS Supply Voltage (V ) ..............................................-0.5V to 6.0V Continuous Power Dissipation (T = +85C) CC A Voltage at TX DISABLE, IN+, IN-, FAULT, 24-Lead Thin QFN SQUELCH, TC1, TC2, MODSET, PEAKSET, BIASSET, (derate 20.8mW/C above +85C).................................1354mW BIAS, BIASMON, COMP, MD, REF, Operating Temperature Range ...........................-40C to +85C PWRMON ...............................................-0.5V to (V + 0.5V) Storage Temperature Range .............................-55C to +150C CC Voltage at OUT+, OUT-.........................(V - 2V) to (V + 2V) Lead Temperature (soldering, 10s) .................................+300C CC CC Current into FAULT ............................................ -1mA to +25mA Current into OUT+, OUT-....................................................60mA 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 = +2.97V to +3.63V, T = -40C to +85C. Typical values are at V = +3.3V, TC1 and TC2 are shorted, PEAKSET open, T = CC A CC A +25C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SQUELCH set low, I = 2mA 32 MOD P-P TX DISABLE set low, peaking is not used I = 15mA 55 68 MOD P-P (Note 1) I CC Supply Current mA Additional current when peaking is used 15 20 (Note 2) Additional current when SQUELCH is high 5 10 I Total current when TX DISABLE is high 3.9 5 CC-SHDN FAULT OUTPUT Output High Voltage V R = 10k to 2.97V 2.4 V OH LOAD Output Low Voltage V R = 4.7k to 3.63V 0.4 V OL LOAD TX DISABLE INPUT Input Impedance 4.7 10.0 k Input High Voltage V 2.0 V IH Input Low Voltage V 0.8 V IL The time for I to reach I when CC CC-SHDN Power-Down Time 50 s TX DISABLE transitions high SQUELCH Squelch Threshold 25 85 mV P-P Squelch Hysteresis 10 mV P-P Time to Squelch Data (Note 3) 0.02 5.00 s Time to Resume from Squelch (Note 3) 0.02 5.00 s BIAS GENERATOR (Note 4) Minimum 1 Bias Current I mA BIAS Maximum 15 5mA I 15mA -8 +8 Accuracy of Programmed Bias BIAS BIAS % Current 1mA I 5mA -12 +12 BIAS 2 MAX3740A