19-2903; Rev 0; 7/03 MAX3656 Evaluation Kit The MAX3656 evaluation kit (EV-Kit) is an assembled demonstration board that provides optical and electrical evaluation of the MAX3656 155Mbps to 2.5Gbps laser driver. The optical output of the evaluation board allows connection with coaxial laser packages as well as BIDI packages. The electrical output of the evaluation board is interfaced to an SMP connector that can be connected to a 50Ω terminated oscilloscope. _________________________Features ♦ Fully Assembled and Tested ♦ Single +3.3V Power-Supply Operation ♦ Allows Optical and Electrical Evaluation ______________ Ordering Information PART MAX3656EVKIT *Exposed Pad TEMP. RANGE -40°C to +85°C IC PACKAGE 24QFN* ______________________________________ Electrical Evaluation Component List DESIGNATION QTY DESCRIPTION C16, C17, C25C28 6 0.01µF ±5% ceramic capacitors (0402) Murata GRM36X7R103J016AD C5, C6, C8 3 0.1µF ±10% ceramic capacitors (0402) Murata GRP155R61A104K C7 D1 1 1 10µF tantalum capacitor (B CASE) AVX TAJB106K010R LED, green T1 package J1-J4, J11 5 SMA connectors, tab contact (edge mount) Johnson 142-0701-851 J10 1 SMP 698 (edge mount) Johnson 131-1701-201 J5, J7, J9, J12, J13 5 Open JP5 1 Open JP6, JP7, JP9, JP11, JP16 5 1X2 pin headers (0.1in centers) JP8, JP10, JP12, JP13, JP15 5 1X3 pin headers (0.1 in centers) Q0 1 Q1 DESIGNATION QTY DESCRIPTION R2, R7, R12, R17, R29, R55, R67, R68, R70, R71, R74, R76, R77 13 Open R1, R22, R26 3 50kΩ potentiometers (3296W) BOURNS Digi-Key 3296W-202-ND R3, R36, R62R65 R30 6 0Ω resistor (0402) 1 121Ω resistor (0402) R33 1 35.7Ω resistor (0402) R34 1 511Ω resistor (0402) R39, R40 2 100Ω resistor (0402) R52 1 30Ω resistor (0402) R53 1 330Ω resistor (0402) R54 1 4.64kΩ resistor (0402) R8 1 4.42kΩ resistor (0402) R9, R10 2 TP3, TP5, TP7, TP9, J17, J19 6 22.1Ω resistor (0402) Test points Digi-Key 5000K-ND U1 1 MAX3656ETG 24-QFN FMMT591A Zetex U3 1 MAX495 8-SOIC 1 FMMT491A Zetex None 10 Shunts R14 1 49.9Ω ±1% resistor (0402) None 1 MAX3656 EV Kit R20, R24 2 3kΩ resistor (0402) None 1 MAX3656 data sheet R28, R32 2 26.7Ω resistor (0402) _________________________________________________________________Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX3656 _______________ General Description MAX3656 Evaluation Kit Evaluates: MAX3656 _________________________________________Optical Evaluation Component List DESIGNATION QTY C10-C15, C30 7 DESCRIPTION 0.01µF ±5% ceramic capacitors (0402) Murata GRM36X7R103J016AD 0.1µF ±10% ceramic capacitors (0402) Murata GRP155R61A104K DESIGNATION QTY DESCRIPTION R61, R119 2 3kΩ resistor (0402) R59, R79, R90 3 50kΩ potentiometers (3296W) BOURNS Digi-Key 3296W-202-ND R82, R120 2 1.5kΩ resistor (0402) R88 1 4.42kΩ resistor (0402) R91, R92, R94, R95, R97, R98, R100, R101 8 Open SB1-SB6 6 Solder Bridge TP1, TP23, TP27, J18, J20 5 Test points Digi-Key 5000K-ND U2 1 MAX3656ETG 24-QFN C18, C20, C21, C32, C35-C37 7 C19 1 C24* D2 1 1 LED, green T1 package J14 1 Open J16 1 J23-J26 4 JP25 1 1X2 pin headers (0.1in centers) JP26, JP28, JP30, JP32, JP33 5 1X3 pin headers (0.1in centers) L1 1 Open Q4 1 FMMT491A Zetex SUPPLIER PHONE FAX R103, R104 2 100Ω resistor (0402) AVX 803-946-0690 803-626-3123 R109, R122 2 15Ω resistor (0402) Digi-Key 218-681-6674 218-681-3380 Murata 814-237-1431 814-238-0490 10µF tantalum capacitor (B CASE) AVX TAJB106K010R 10pF ceramic capacitor (0402) Phone Jack Digi-Key A9036-ND SMA connectors, tab contact (edge mount) Johnson 142-0701-851 R118 1 Open R121* 1 43Ω resistor (0402) R124 1 10Ω resistor (0402) R126 R41, R42, R113-R116 1 13Ω resistor (0402) 6 0Ω resistor (0402) R43 1 511Ω resistor (0402) R44, R45 2 4.7kΩ resistor (0402) U4 1 DS1847 14-TSSOP None 6 Shunts None 1 MAX3656 EV Kit None 1 MAX3656 data sheet *These components are part of a compensation network to reduce overshoot and ringing caused by parasitic inductance of the laser. For most lasers the starting values will be R121 = 43Ω and C24 = 10pF. These values should be experimentally tested to optimize the output waveform. ______________Component Suppliers Note: Please indicate that you are using the MAX3656 when ordering from these suppliers. 2 _________________________________________________________________________________________ MAX3656 Evaluation Kit The MAX3656 EV kit’s electrical section comes equipped with APC open loop functionality, but can be configured for APC closed loop operation. 1) Install a shunt on JP15 from center pin to GND. 2) Install a shunt on JP13 from center pin to VCC. 3) Install a shunt on JP8, JP12, and JP10 from the center pin to R20, R24, and R8 respectively. 4) Set R22, R26, and R1 to 50kΩ. Measure their values on TP7, TP9, and TP5 respectively. 5) Connect the differential data signal on J1 and J2 with the common mode for each single ended signal within the MAX3656 data sheet limits. 6) Connect a +3.3V power supply to J17. ground to J19. 7) Configure the MAX3656 in operation in one of two ways. 8) Connect continuous mode a) Remove R39. Connect a 1kΩ resistor on R70 and a 3kΩ resistor on R71, R67, and R68. b) Connect a +2.3V power supply on J3. Connect a +1.7V power supply on J4. Connect J10 (OUT+) to a high-speed 50Ω oscilloscope, through a DC blocking capacitor. An attenuator might be necessary to meet the oscilloscope requirements, since the voltage at OUT+ may exceed the maximum voltage for the oscilloscope. Reduce the resistance on R26 to change the amplitude of the modulation. The modulation current is the amplitude from the oscilloscope divided by 15Ω, assuming no external attenuation. 11) Reduce the resistance on R22 to change the bias current. Change the bias current until the APC loop is operational. The APC loop is operational when the LED, D1, is lit. 12) The bias current is (VCC – Voltage at BIAS+) divided by 30Ω. 13) Connect for burst mode operation by removing the voltage sources on J3 and J4 and removing R67, R68, R70, and R71. Install a 100Ω resistor on R39. 14) Connect the burst signal on J3 and J4. ________________ Optical Quick Start 1) Install a shunt on JP26 from the center pin to GND. 2) Install a shunt on JP28 from the center pin to VCC. 3) Shunt JP25. 4) Install a shunt on JP33, JP30, and JP32 from the center pin to R120, R119, and R88 respectively. 5) Set R79, R59, and R90 to 50kΩ. Measure their values on TP27, TP23, and TP1 respectively. 6) Connect the differential data signal on J26 and J25 with the common mode for each single ended signal within the MAX3656 data sheet limits. 7) The EV kit is designed to allow connection of a variety of possible laser/monitor diode pin configurations. Connect a TO-header style laser with monitor diode as follows: APC Open Loop 9) Remove shunts on JP9 and JP6. 10) Connect J11 to a high-speed 50Ω oscilloscope. Reduce the resistance on R1 to change the amplitude of the bias. The bias current is the amplitude from the oscilloscope divided by 15Ω. 11) Connect for burst mode operation by removing the voltage sources on J3 and J4 and removing R67, R68, R70, and R71. Install a 100Ω resistor on R39. 12) Connect the burst signal on J3 and J4. APC Closed Loop 9) Remove R28 and R30. Install a 0Ω resistor for R29. 10) Install shunts on JP9, JP6, JP16, and JP7. • Keeping its leads as short as possible, connect the laser diode to two of the three pads on the top (component) side of the PC board. Solder the laser diode cathode to the center pad, and solder the anode to either of the other two pads (they are both connected to VCC). • Connect the monitor photodiode to two of the five pads on the bottom (solder) side of the PC board, directly below the laser diode pads. Connect the anode and cathode of the photodiode as shown in figure 1. 8) Connect +3.3V power supply to J18. ground to J20. 9) Configure the MAX3656 in operation in one of two ways. Connect continuous mode a) Remove R103. Connect a 1kΩ resistor on R101 and a 3kΩ resistor on R100, R92, and R91. b) Connect a +2.3V power supply on J24. Connect a +1.7V power supply on J23. _________________________________________________________________________________________ 3 Evaluates: MAX3656 ______________ Electrical Quick Start Evaluates: MAX3656 MAX3656 Evaluation Kit 10) Reduce the resistance on R90 to set the maximum allowable bias current. 11) Reduce the resistance on R79 to achieve the desired average power. The average power can be measured by connecting the output of the laser to an optical power meter. 12) Reduce the resistance on R59 to achieve the desired extinction ratio. The extinction ratio can be measured on an oscilloscope connected to an optical/electrical converter. Laser overshoot and _______________Adjustment ringing can be improved by appropriate selection of R121 and C24. 13) The APC loop is functional when the LED, D2, is lit. 14) Connect for burst mode operation by removing the voltage sources on J24 and J23 and removing R91, R92, R100, and R101. Install a 100Ω resistor on R103 15) Connect the burst signal on J24 and J23. and Control Descriptions (see Quick Start first) COMPONENT NAME FUNCTION OPTICAL ELECTRICAL D2 D1 FAIL When lit the APC loop is tracking the average power and FAIL is high. When not lit the APC loop is not tracking the average power and FAIL is low. JP25 JP16 --- Shunting drives the base of a transistor to swtich LED on and off based on the TTL output of FAIL. JP26 JP15 EN When connected to VCC disables the MAX3656. When connected to GND enables the MAX3656. JP28 JP13 LONGB --- JP7 --- Shunting this jumper sets IMD/IBIAS = 1/11. Leaving this jumper open sets IMD/IBIAS = 3/497. --- JP6, JP9 --- Shunting these jumpers, removing R28 and R30, and installing a 0Ω resistor on R29 allows closed loop opertion. --- JP8 --- Allows connecting the APCSET pin to either the resistor, R20, or to a fixed, uninstalled resistor R17. --- JP12 --- Allows connecting the MODSET pin to either the resistor, R24, or to a fixed, uninstalled resistor R7. --- JP10 --- Allows connecting the BIASMAX pin to either the resistor, R8, or to a fixed, uninstalled resistor R12. JP33 --- --- Allows conneting the APCSET pin to either the DS1847 or the resistor R120. JP30 --- --- Allows connecting the MODSET pin to either the DS1847 or the resistor R119. JP32 --- --- Allows connecting the BIASMAX pin to either the resistor, R88, or to a fixed, uninstalled resistor R118. Connect the center pin to VCC or GND to set the LONGB pin. 4 _________________________________________________________________________________________ MAX3656 Evaluation Kit --- --- --- R79 R22 --- Adjusts the current going into APCSET, which is used to set the average power when APC loop is closed. R59 R26 --- Adjusts the current going into MODSET, which is used to set the modulation current amplitude. R90 R1 --- Adjusts the current going into BIASMAX, which is used to set the maximum bias current with closed APC loop and the bias current with open APC loop. R94, R95, R98, R97, R101, R100, R92, R91 Allows for external DC biasing for PECL termination on the MAX3656 inputs. Remove R40 and R39 when connecting the resistors. Allows for external DC biasing for PECL termination on the MAX3656 inputs. Remove R104 and R103 when connecting the resistors. _________________________________________________________________________________________ 5 Evaluates: MAX3656 R76, R77, R2, R74, R67, R68, R70, R71 --- Evaluates: MAX3656 MAX3656 Evaluation Kit C ON F I GU R ATI ON 11 CONFIGURATION C ON F I GU R ATI ON 22 CONFIGURATION TOP OF PC BOAR D TOP OF PC BOAR D R124 V CC R124 VC C LD VC C V CC T0 -4 6 C AN L ASER /PH OTOD IOD E PAIR LD PD SOL D ER BR ID GES VC C T0 -4 6 C AN L ASER /PH OTOD IOD E PAIR PD VC C VC C SOL D ER BR ID GES VC C TO MD TO MD BOTTOM OF PC BOAR D BOTTOM OF PC BOAR D CONFIGURATION C ON F I GU R ATI ON 33 CONFIGURATION C ON F I GU R ATI ON 4 4 TOP OF PC BOAR D TOP OF PC BOAR D R124 V CC R124 V CC LD V CC VC C T0 -4 6 C AN L ASER /PH OTOD IOD E PAIR LD PD SOL D ER BR ID GES VC C T0 -4 6 C AN L ASER /PH OTOD IOD E PAIR PD VC C SOL D ER BR ID GES VC C VC C TO MD BOTTOM OF PC BOAR D TO MD BOTTOM OF PC BOAR D Figure 1. Attachment of Laser Diode/Monitor Diode to the MAX3656 EV kit 6 _________________________________________________________________________________________ MAX3656 Evaluation Kit R26 50k Ω TP 5 R1 50k Ω R12 OP E N TP 9 R20 3k Ω TP 5 R8 4.42k Ω R24 3k Ω JP8 J P 12 J P 10 R54 4.64k Ω J9 OP E N JP5 R53 OP E N V C C 330 Ω Q0 JP6 R55 OP E N V CC U3 2 6 V CC C16 C17 V 0.01 µ F C C 0.01 µ F R77 R40 OP E N 100 Ω R39 100 Ω R67 OP E N R68 OP E N C8 0.1 µ F C7 C6 10 µ F 0.1 µ F + J 19 J5 OP E N GND MD V CC B IA S + B IA S - B E N- V CC 7 8 9 10 V CC 11 C27 0.01 µ F D1 Q1 12 C25 0.01 µ F R14 49.9 Ω 16 J 10 JP9 V CC R28 26.7 Ω 14 13 R32 26.7 Ω R33 35.7 Ω V CC R29 OP E N J 11 R30 121 Ω C28 0.01 µ F V CC R3 0Ω V CC J 13 OP E N V CC J 17 B E N+ J P 15 R10 22.1 Ω 17 LONGB R71 OP E N V CC R65 0Ω 6 R9 22.1 Ω V C C 15 M AX3656 GND R63 0Ω OUT+ FA IL 5 R70 OP E N J3 J4 IN- R74 OP E N V CC TP 3 V CC V C C 18 U1 3 3 M A X 495 19 OUT- V C26 C C 4 V CC 0.01 µ F R2 OP E N 20 IN+ V CC V CC R64 0Ω J2 2 GND R62 0Ω EN J1 V CC 21 B IA S MA X R36 0Ω R76 OP E N 22 MODS E T V CC 1 A P CS E T V CC 23 V CC R52 30 Ω JP7 7 4 24 Evaluates: MAX3656 R7 OP E N J P 11 R22 50k Ω R17 OP E N J P 13 J 12 OP E N J P 16 R34 511 Ω C5 0.1 µ F J7 OP E N Figure 2. MAX3656 EV Kit Schematic-Electrical Configuration _________________________________________________________________________________________ 7 MAX3656 Evaluation Kit J 16 A M P P HONE 6 6 5 4 3 2 1 R45 4.7k Ω U4 1 14 12 4 11 5 10 6 9 7 8 R79 50k Ω R82 1.5k Ω TS S OP 14 R59 50k Ω R61 3k Ω TP 27 R90 50k Ω R118 OP E N TP 23 R120 1.5k Ω TP 1 R88 4.42k Ω R119 3k Ω J P 33 J P 30 J P 32 V CC 2 C12 0.01 µ F 5 R101 OP E N J 24 R114 0Ω 6 R100 OP E N R103 100 Ω V C C2 R113 J 23 0Ω R92 OP E N J 20 C19 C20 10 µ F 0.1 µ F + GND MD VCC B IA S MA X OUT+ B E N+ B IA S + B E N- B IA S - V CC2 7 8 9 10 V CC2 C14 0.01 µ F 18 R109 15 Ω 11 C37 0.1 µ F C11 0.01 µ F C36 0.1 µ F SB5 V CC2 SB4 R124 10 Ω 16 R121 43 Ω C24 10pF 14 13 R122 15 Ω R126 13 Ω V CC2 C13 0.01 µ F L1 OP E N 12 V CC2 J P 28 V CC2 Q4 SB6 17 V C C 15 M AX3656 J 14 OP E N V C C2 C18 0.1 µ F IN- J P 26 R91 OP E N J 18 U2 V C15 C C 2 4 V CC 0.01 µ F R98 OP E N R97 OP E N V C C2 OUT- IN+ LONGB R116 0Ω V CC2 19 GND V CC 2 J 25 3 20 V CC FA IL R95 R115 OP E N R104 0Ω 100 Ω 2 GND J 26 V CC V CC R41 0Ω R94 OP E N 21 22 MODS E T V CC 2 1 23 A P CS E T 24 V CC2 C10 V 0.01 µ F C C 2 SB3 D S1847 SB2 R42 0Ω C30 0.01 µ F 13 2 3 V CC2 SB1 R44 4.7k Ω EN Evaluates: MAX3656 V CC2 D2 J P 25 R43 511 Ω C21 0.1 µ F Figure 3. MAX3656 EV Kit Schematic-Optical Configuration 8 _________________________________________________________________________________________ C32 0.1 µ F C35 0.1 µ F MAX3656 Evaluation Kit Evaluates: MAX3656 Figure 4. MAX3656 Component Placement Guide-Component Side Figure 5. MAX3656 Component Placement Guide-Solder Side _________________________________________________________________________________________ 9 Evaluates: MAX3656 MAX3656 Evaluation Kit Figure 6. MAX3656 PC Board Layout-Component Side Figure 7. MAX3656 PC Board Layout-Ground Plane 10 _________________________________________________________________________________________ MAX3656 Evaluation Kit Evaluates: MAX3656 Figure 8. MAX3656 PC Board Layout-Power Plane Figure 9. MAX3656 PC Board Layout-Solder Side 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 ______________ 11 2003 Maxim Integrated Products Printed USA __ 11 is a registered trademark of Maxim Integrated Products.