MAX3656 19-2790 Rev 4 9/10 155Mbps to 2.5Gbps Burst-Mode Laser Driver General Description Features Multirate Operation from 155Mbps to 2.5Gbps The MAX3656 is a burst-mode laser driver that oper- ates at data rates from 155Mbps up to 2.5Gbps. The Burst Enable/Disable Delay <2ns laser driver accepts either positive-referenced emitter- Burst On-Time of 576ns to Infinity coupled logic (PECL) or current-mode logic (CML) data Infinite Bias-Current Hold Time Between Bursts inputs and provides bias and modulation current for the laser diode. The device can switch the laser diode from DC-Coupled Operation with Single +3.3V Power a completely dark (off) condition to a full (on) condition Supply (with proper bias and modulation currents) in less than 40mA Typical Supply Current 2ns. The MAX3656 incorporates DC-coupling between Programmable Bias Current from 1mA to 70mA laser driver and laser diode and operates with a single- Programmable Modulation Current from 10mA supply voltage as low as +3.0V. to 85mA A digital automatic power-control (APC) loop is provided Automatic Average Power Control with Failure to maintain the average optical power over the full tem- Monitor (No C Capacitor Needed) APC perature range and lifetime. The APC loop is functional APC Loop Initialization 3 Bursts for a minimum burst on-time of 576ns and minimum burst off-time of 96ns, with no limit on the maximum Ordering Information burst on- or off-time. A fail monitor is provided to indi- cate when the APC loop can no longer maintain the PART TEMP RANGE PIN-PACKAGE average power. The MAX3656 can be configured for MAX3656ETG -40C to +85C 24 Thin QFN-EP* nonburst-mode applications (continuous mode) by con- necting burst enable (BEN) high. For power saving, the MAX3656ETG+ -40C to +85C 24 Thin QFN-EP* MAX3656 provides enabling and disabling functionality. +Denotes a lead(Pb)-free/RoHS-compliant package. The modulation current can be set from 10mA to 85mA *EP = Exposed pad. and the bias current can be set from 1mA to 70mA. The MAX3656 is packaged in a small, 24-pin, 4mm Functional Diagram appears at end of data sheet. 4mm thin QFN package and consumes only 132mW (typ), excluding bias and modulation currents. Typical Application Circuit Applications Fiber-to-the-Home (FTTH) and Fiber-to-the- +3.3V Business (FTTB) Broadband Access Systems Passive Optical Network (PON) Transmitters +3.3V +3.3V 10 10nH APON, EPON, and GPON Upstream Transmitters 130 130 Pin Configuration SERIAL IN+ 15 DATA IN- OUT- TOP VIEW SOURCE 5.6 82 82 24 23 22 21 20 19 OUT+ V 1 18 CC VCC 5.6 75 MAX3656 BIAS+ IN+ 2 17 OUT- +3.3V 27pF IN- 3 16 OUT+ +3.3V 10 MAX3656 V BIAS- CC 15 V 4 CC 130 130 BEN+ 5 14 BIAS+ BEN+ BURST *EP CONTROL BEN- MD BEN- 6 13 BIAS- 7 8 9 101112 82 82 THIN QFN *EXPOSED PAD IS CONNECTED TO GND 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. EN APCSET GND MODSET BIASMAX VCC V CC FAIL MD GND GND LONGB EN APCSET GND MODSET FAIL BIASMAX LONGB V CC155Mbps to 2.5Gbps Burst-Mode Laser Driver ABSOLUTE MAXIMUM RATINGS Supply Voltage, V ..............................................-0.5V to +6.0V Continuous Power Dissipation (T = +85C) CC A Current into BIAS+, BIAS-, OUT+, OUT- ........-20mA to +150mA 24-Lead Thin QFN Current into MD.................................................... -5mA to +5mA (derate 27.8mW/C above +85C).............................1805mW Current into FAIL...............................................-10mA to +10mA Operating Ambient Temperature Range (T )......-40C to +85C A Voltage at IN+, IN-, BEN+, BEN-, EN, Storage Ambient Temperature Range (T ) ...-55C to +150C STG LONGB...................................................-0.5V to (V + 0.5V) Lead Temperature (soldering,10s) ..................................+300C CC Voltage at MODSET, APCSET, BIASMAX .............-0.5V to +3.0V Soldering Temperature (reflow) Voltage at OUT+, OUT-.............................+0.5V to (V + 1.5V) Lead(Pb)-free...............................................................+260C CC Voltage at BIAS+, BIAS-............................+0.5V to (V + 0.5V) Containing lead(Pb).....................................................+240C CC 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. OPERATING CONDITIONS PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V 3.0 3.3 3.6 V CC Supply Turn-On Time 10% to 90% 0.001 10 ms Ambient Temperature -40 +85 C Data Mark Density Average 50 % Consecutive Identical Digits CID 80 Bits Data Rate 155 2500 Mbps Monitor Diode Capacitance C For minimum burst on-time (Note 1) 15 pF MD ( m oni tor curr ent) / ( l aser cu r r ent (ab ov e I ) ) T H Laser-to-Monitor Diode Gain A 0.005 0.050 A/A LMD ( N otes 2, 3) Extinction Ratio r 10 log (P /P ) (Note 3) 8.2 12.0 dB e 1 0 Note 1: Larger MD capacitance increases the minimum burst on-time. Note 2: Laser-to-monitor gain equals the laser slope efficiency multiplied by the photodiode responsivity multiplied by the losses due to laser-to-monitor diode coupling (A = L ). LMD LASER MONITORDIODE LASER-TO-MONITORDIODE where L = laser-to-monitor diode coupling loss. A can also be calculated by: LMD 2I r I MD e A = LMD I rI+ MOD e where I , I , and r (extinction ratio) are set externally. MD MOD e Note 3: Operation outside this range degrades APC loop performance. ELECTRICAL CHARACTERISTICS (Typical values are at V = +3.3V, I = 20mA, I = 25mA, extinction ratio = 10dB, and T = +25C, unless otherwise noted.) CC BIAS MOD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Power-Supply Current I (Note 1) 40 70 mA CC INPUT SPECIFICATIONS Differential Input Voltage V , V 0.2 1.6 V IN BEN P-P V - V - V - CC CC CC Common-Mode Input Voltage V V CM 1.49 1.32 V /4 IN 2 MAX3656