19-2903; Rev 2; 8/10 MAX3656 Evaluation Kit The MAX3656 evaluation kit (EV kit) is an assembled demonstration board that provides optical evaluation of the MAX3656 155Mbps to 2.5Gbps burst-mode laser driver. The evaluation board allows connection with coaxial laser packages as well as BIDI packages. Features S Fully Assembled and Tested S Adjustable Laser Bias Current S Adjustable Laser Modulation Current S Single +3.3V Power-Supply Operation EV Kit Contents S MAX3656 EV Kit Board Ordering Information PART TYPE MAX3656EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component List DESIGNATION QTY DESCRIPTION 1 1FF Q10% ceramic capacitor (0402) Murata GRM155R61A105KE15D C2 1 1000pF Q10% ceramic capacitor (0402) Murata GRM155R71H102KA01D C3, C10-C15 7 0.1FF Q10% ceramic capacitors (0402) Murata GRM155R61A104KA01D C1 C19 C20 C21 C24 D2 1 10FF Q10% tantalum capacitor (B case) AVX TAJB106K010RNJ 1 0.1FF Q10% ceramic capacitor (0603) Murata GRM188R71H104KA93D 1 0.01FF Q10% ceramic capacitor (0603) TDK C1005X8R1E103K QTY DESCRIPTION JP26, JP28, JP30, JP32, JP33 5 3-pin headers, 0.1in center Sullins PEC36SAAN JP26, JP28, JP30, JP32, JP33 5 Shunts Sullins SSC02SYAN L1 1 10nH Q5% inductor (0402) Murata LQG15HS10NJ02 Q1 1 npn transistor Zetex FMMT491ATA R1 1 15I Q5% resistor (0402) R2, R3 2 10I Q5% resistors (0402) R12, R126 2 5.6I Q5% resistors (0402) R43 1 200I Q5% resistor (0603) R59, R79, R90 3 50kI variable resistors Bourns 3296W-1-503LF R61, R82, R118 0 Not installed, resistors (0603) R88 1 4.3kI Q5% resistor (0603) R91, R92, R94, R95, R97, R98, R100, R101 0 Not installed, resistors (0402) R103, R104 2 100I Q1% resistors (0402) 1 27pF Q5% ceramic capacitor (0402) Murata GRM1555C1H270JZ01D R113-R116 4 0I Q5% resistors (0402) 1 Green LED, SMD Panasonic LNJ311G8PRA R119 1 3kI Q5% resistor (0603) R120 1 1.5kI Q5% resistor (0603) R121 1 75I Q5% resistor (0402) U1 1 Burst-mode laser driver (24 TQFN-EP*) Maxim MAX3656ETG+ -- 1 PCB: MAX3656 EVALUATION BOARD+, Rev D D3, D4 2 Diodes Panasonic MA27P0100L D5 0 Laser, user supplied J18, J20, TP1, TP2 4 Test points Keystone 5000 4 SMA connectors, edge mount, tab contact Johnson 142-0701-851 J23-J26 DESIGNATION *EP = Exposed pad. ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. Evaluates: MAX3656 General Description Evaluates: MAX3656 MAX3656 Evaluation Kit Quick Start To evaluate the MAX3656 with a laser diode, configure the EV kit as follows: 1) Pull shunts off all jumpers (JP33, JP30, JP32, JP26, and JP28). 2) Set RAPCSET to 20kI by adjusting the APCSET variable resistor R79 until the measured resistance between the VAR pin of jumper JP33 and GND is 20kI. Then install a shunt on the VAR side of jumper JP33. 3) Set RMODSET to 20kI by adjusting the MODSET variable resistor R59 until the measured resistance between the VAR pin of jumper JP30 and GND is 20kI. Then install a shunt on the VAR side of jumper JP30. 11) Turn on the power supply and adjust APCSET (R79) for the desired average optical power, then adjust MODSET (R59) for the desired extinction ratio. Note: The APC loop is functional when the FAIL indicator, green LED D2, is on. The LED is off if the BIASMAX is set too low, the monitor diode (MD) pin is not connected, or the modulation current is set too high. 12) If the eye diagram contains too much overshoot or the rise/fall times are too slow, experimentally adjust the values of the RL peaking network (R3, L1) and RC shunt network (R121, C24) to better match the characteristics of the laser. Applications Information Continuous Mode Operation Set RBIASMAX to 7kI by adjusting the BIASMAX variable resistor R90 until the measured resistance between the VAR pin of jumper JP32 and GND is 7kI. Then install a shunt on the VAR side of jumper JP32. For continuous mode operation, switch the differential burst-enable input (BENQ) to a constant high in one of two ways: * Remove resistor R103. Install a 1kI resistor on R101 and 3kI resistors on R91, R92, and R100. 5) Connect the EN pin to GND by installing a shunt on the GND side of jumper JP26. * 6) Connect the LONGB pin to GND by installing a shunt on the GND side of jumper JP28. Connect a +2.3V supply to BEN+ and a +1.7V supply to BEN- (or a differential 0.6V supply between BEN+ and BEN-). 7) Solder a laser to edge connection D5. See Figure 1 for a view of how the laser should be mounted on the EV kit. Be sure to keep the laser leads as short as possible to minimize parasitic inductance. If needed, an LVPECL Thevenin equivalent load termination of 50I to (VCC - 2V) can be created by doing the following: * Remove resistors R103 and R104. 8) Connect a differential data source to IN+ (J26) and IN- (J25) and a differential burst-enable source to BEN+ (J24) and BEN- (J23). Make sure the differential signals are between 200mVP-P and 1600mVP-P and the common-mode is between (VCC - 1.49V) and (VCC - VIN/4). See the Applications Information section for more options. * Solder 130I resistors on R92, R94, R98, and R101. * Solder 82I resistors on R91, R95, R97, and R100. 4) 9) Attach a +3.3V power supply to J18 (+3.3V) and J20 (GND). Set the current limit to 250mA. 10) Connect the output of the user-supplied laser to an optical-to-electrical converter that has the appropriate bandwidth (filter) for the intended application. LVPECL Input Terminations For more information, refer to Application Note 291: HFAN-01.0: Introduction to LVDS, PECL, and CML. LVCMOS Burst Enable To drive the burst-enable input (BEN+) with singleended LVCMOS levels, do the following: * Remove resistors R103 and R114. * Solder 3kI resistor on R114. * Solder 5kI resistors on R101 and R92. * Solder 9kI resistor on R91. 2 _______________________________________________________________________________________ MAX3656 Evaluation Kit Evaluates: MAX3656 TOP OF PCB LD PD BOTTOM OF PCB Figure 1. Laser Attachment Table 1. Adjustment and Control Descriptions COMPONENT JP33 NAME APCSET SELECT R79 APCSET RESISTOR JP30 MODSET SELECT FUNCTION This jumper connects a fixed resistance (R82, not installed) or a variable resistance (R120 + R79) between the APCSET pin and GND. This 50kI variable resistor, in addition to a 1.5kI series resistor (R120), sets the external resistance between the APCSET pin and GND when a shunt is installed on the VAR side of jumper JP33. Turning the variable resistor clockwise increases the average optical power. This jumper connects a fixed resistance (R61, not installed) or a variable resistance (R119 + R59) between the MODSET pin and GND. This 50kI variable resistor, in addition to a 3kI series resistor (R119), sets the external resistance between the MODSET pin and GND when a shunt is installed on the VAR side of jumper JP30. Turning the variable resistor clockwise increases the modulation current and extinction ratio. R59 MODSET RESISTOR JP32 BIASMAX SELECT R90 BIASMAX RESISTOR JP26 EN JP28 LONGB This jumper is used to connect the LONGB pin to VCC (burst on-time > 1.2Fs) or to GND (burst on-time 1.2Fs). D2 FAIL The APC loop is functional when the LED is on. The LED is off if the BIASMAX is set too low, the monitor diode (MD) pin is not connected, or the modulation current is set too high. This jumper connects a fixed resistance (R118, not installed) or a variable resistance (R88 + R90) between the BIASMAX pin and GND. This 50kI variable resistor, in addition to a 4.3kI series resistor (R88), sets the external resistance between the BIASMAX pin and GND when a shunt is installed on the VAR side of jumper JP32. Turning the variable resistor clockwise increases the maximum bias current. This jumper is used to connect the EN pin to VCC (driver disabled) or to GND (driver enabled). _______________________________________________________________________________________ 3 Evaluates: MAX3656 MAX3656 Evaluation Kit Figure 2. MAX3656 EV Kit Schematic 4 _______________________________________________________________________________________ MAX3656 Evaluation Kit Evaluates: MAX3656 Figure 3. MAX3656 EV Kit Component Placement Guide--Component Side _______________________________________________________________________________________ 5 Evaluates: MAX3656 MAX3656 Evaluation Kit Figure 4. MAX3656 EV Kit PCB Layout--Component Side 6 _______________________________________________________________________________________ MAX3656 Evaluation Kit Evaluates: MAX3656 Figure 5. MAX3656 EV Kit PCB Layout--Ground Plane _______________________________________________________________________________________ 7 Evaluates: MAX3656 MAX3656 Evaluation Kit Figure 6. MAX3656 EV Kit PCB Layout--Power Plane 8 _______________________________________________________________________________________ MAX3656 Evaluation Kit Evaluates: MAX3656 Figure 7. MAX3656 EV Kit PCB Layout--Solder Side _______________________________________________________________________________________ 9 Evaluates: MAX3656 MAX3656 Evaluation Kit Figure 8. MAX3656 EV Kit Component Placement Guide--Solder Side 10 MAX3656 Evaluation Kit REVISION NUMBER REVISION DATE 0 7/03 Initial release 1 10/04 Corrected the electrical and optical component list, corrected the quick start steps, added text about diodes to OUT- and BIAS-, corrected the schematics and replaced the layout figures 2 8/10 Redesigned the EV kit to work up to 2.5Gbps DESCRIPTION PAGES CHANGED -- 1-4, 7-11 All Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2010 Maxim Integrated Products 11 Maxim is a registered trademark of Maxim Integrated Products, Inc. Evaluates: MAX3656 Revision History Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX3656EVKIT+