19-2159; Rev 0; 9/01 MAX3273 Evaluation Kit Features ♦ Fully Assembled and Tested The EV kit is composed of two independent sections, one optical and one electrical, on the PC board. The output of the electrical evaluation section is interfaced to an SMA connector that can be connected to a 50Ω terminated oscilloscope. The output of the optical evaluation section is configured for attachment to a laser/ monitor diode. ♦ Input Termination Provided On-Board ♦ Single 3.3V Power-Supply Operation ♦ Enables Optical and Electrical Evaluation Ordering Information PART MAX3273EVKIT TEMP RANGE IC PACKAGE -40°C to +85°C 24 QFN* *Exposed pad Electrical Evaluation Component List DESIGNATION QTY C13, C40 2 C14, C18, C21, C23, C24 DESCRIPTION DESIGNATION QTY 10µF ±20% tantalum capacitors AVX TAJC106K016 L6 1 33µH power inductor Coilcraft DO1608C-333 5 0.1µF ±10% ceramic capacitors (0402) L7, L12 2 Ferrite beads (0805) Murata BLM21A102S C15, C16, C31, C32, C37, C45 6 0.01µF ±10% ceramic capacitors (0402) L9 1 1.2µH inductor Coilcraft 1008CS-122XKBC C27, C28 2 0.056µF ±10% ceramic capacitors (0603) L10, L11 2 Ferrite beads (0603) Murata BLM11HA601SG C30 1 470pF ±10% ceramic capacitor (0402) R4 1 1kΩ ±1% resistor (0603) R5 1 681Ω ±1% resistor (0603) C41 1 0.01µF ±10% ceramic capacitor (0603) R12 1 500kΩ variable resistor R13, R37 2 100kΩ variable resistors D3 1 LED, red T1 package R17 1 110Ω ±1% resistor (0603) D4 1 Diode DIO-S1A R22, R38 2 49.9Ω ±1% resistors (0402) J5–J9 5 SMA connectors (tab contact) EFJohnson 142-0701-851 R23, R25 2 Open JU4, JU5, JU9–JU13, JU18–JU20 10 1 × 2-pin headers (0.1in centers) JU7, JU8 2 1 × 3-pin headers (0.1in centers) DESCRIPTION R26 1 2kΩ ±1% resistor (0402) R28, R30 2 100Ω ±5% resistors (0201) R29 1 0Ω resistor (0402) R46 1 5.11Ω ±1% resistor (0603) R47 1 392Ω ±1% resistor (0603) ________________________________________________________________ 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: MAX3273 General Description The MAX3273 evaluation kit (EV kit) is an assembled demonstration board that provides optical and electrical evaluation of the MAX3273. Evaluates: MAX3273 MAX3273 Evaluation Kit Electrical Evaluation Component List (continued) DESIGNATION QTY DESIGNATION QTY R51 1 24.9Ω ±1% resistor (0402) None 10 Shunts Q2 1 PNP transistor (SOT23) Zetex FMMT591A None 1 MAX3273 evaluation kit None 1 MAX3273 data sheet U3 1 MAX495ESA (8 SO) U4 1 MAX3273EGG (24 QFN) VCC1, GND1, TP2, TP3, TP8, TP10–TP13, TP22 10 Test points DESCRIPTION DESCRIPTION Optical Evaluation Component List DESIGNATION QTY DESCRIPTION C1, C2, C9, C10, C11, C17, C38 7 0.01µF ±10% ceramic capacitors (0402) 4 0.1µF ±10% ceramic capacitors (0402) C3–C6 DESIGNATION QTY DESCRIPTION JU6, JU14–JU17 5 1 × 2-pin headers (0.1in centers) L1 1 33µH power inductor Coilcraft DO1608C-333 L2, L3, L5 3 Ferrite beads (0603) Murata BLM11HA601SG L4 1 1.2µH inductor Coilcraft 1008CS-122XKBC 1 0.056µF ±10% ceramic capacitor (0402) 1 470pF ±10% ceramic capacitor (0402) R1 1 1kΩ ±1% resistor (0603) 1 Open, user-supplied (0402)* R2 1 500kΩ variable resistor C19 1 10µF ±20% tantalum capacitor AVX TAJB106K016 R3 1 75Ω ±1% resistor (0402) R6 1 24.9Ω ±1% resistor (0402) C20, C22 2 0.01µF ±10% ceramic capacitors (0603) R7 1 2kΩ ±1% resistor (0402) 0Ω resistor (0402) C7 C8 C12 R8 1 R9, R14 2 100kΩ variable resistors R10, R11 2 100Ω ±5% resistors (0201) C36 1 100pF ±5% ceramic capacitor (0603) D1 1 LED, red T1 package R15 1 681Ω ±1% resistor (0603) D2 1 Open, user-supplied laser diode R16 1 110Ω ±1% resistor (0603) 1 Open, user-supplied (0402)* J1–J4 4 SMA connectors (tab contact) EFJohnson 142-0701-801 R18 R20 1 20Ω ±1% resistor (0402) JU2, JU3 2 1 × 3-pin headers (0.1in centers) R21 1 49.9Ω ±1% resistor (0402) *These components are part of the compensation network, which can reduce overshoot and ringing. Parasitic series inductance introduces a zero into the laser’s frequency response. R18 and C12 add a pole to cancel this zero. Starting values for most coaxial lasers is R18 = 75Ω in series with C12 = 3.3pF. These values should be experimentally adjusted until the output waveform is optimized. 2 _______________________________________________________________________________________ MAX3273 Evaluation Kit DESCRIPTION 5) Adjust R37, the RMODSET potentiometer, for 10kΩ resistance between TP10 and ground. 6) Adjust R12, the RBIASMAX potentiometer, for 10kΩ resistance between TP2 and ground. DESIGNATION QTY U1 1 MAX3273EGG (24 QFN) VCC2, GND2, TP1, TP4–TP7, TP9, TP14 7) Adjust R13, the RAPCSET potentiometer, for 10kΩ resistance between TP3 and ground. 9 Test points 8) Apply a differential input signal (200mV P-P to 1600mVP-P) between J7 and J8 (DATA+ and DATA-). None 8 Shunts None 1 MAX3273 evaluation kit None 1 MAX3273 data sheet 10) Attach a high-speed oscilloscope with a 50Ω input to J9. Component Suppliers SUPPLIER 9) If the latch is enabled, apply a differential clock signal (200mVP-P to 1600mVP-P) between J5 and J6 (CLK+ and CLK-). PHONE FAX AVX 803-946-0690 803-626-3123 Coilcraft 847-639-6400 847-639-1469 Murata 814-237-1431 814-238-0490 Zetex 516-543-7100 516-864-7630 Quick Start 11) Power-up the board and adjust the power supply until the voltage between TP11 and ground is +3.3V (VCC). 12) Adjust R12 until the desired laser bias current is achieved. V -V IBIAS = TP13 TP22 5.11Ω 13) Adjust R37 until the desired laser modulation current is achieved. IMOD = Electrical Evaluation In the electrical configuration, an automatic power control (APC) test circuit is included to emulate a semiconductor laser with a monitor photodiode. Monitor diode current is provided by Q2, which is controlled by an operational amplifier (U3). The APC test circuit consists of U3 and Q2, and applies the emulated monitor diode current (the laser bias current divided by a factor of 77) to the MD pin of the MAX3273. To ensure proper operation in the electrical configuration, set up the evaluation board as follows: 1) Place shunts on JU5, JU9–JU12, JU18, and JU20. 2) If the EV kit is to be used in open loop (no APC), place a shunt on JU4. (Refer to the Design Procedure section of the MAX3273 data sheet.) 3) If data is to be latched, place the shunt across pin 1 (VCC, square pad) and pin 2 (LATCH) of JU7 to enable the input clock; otherwise leave open. 4) To enable the outputs, place a shunt across pin 2 (EN) and pin 3 (GND) of JU8. Note: When performing the following resistance checks, manually set the ohmmeter to a high range to avoid forward-biasing the on-chip ESD protection diodes. Signal Amplitude (Volts) 25Ω Optical Evaluation For optical evaluation of the MAX3273, configure the evaluation kit as follows: 1) Place shunts on JU15, JU16, and JU17. 2) If the EV kit is to be used in open loop (no APC), place a shunt on JU14. (Refer to the Design Procedure section of the MAX3273 data sheet.) 3) If data is to be latched, place the shunt across pin 1 (VCC, square pad) and pin 2 (latch) of JU2 to enable the input clock; otherwise leave open. 4) To enable the outputs, place a shunt across pin 2 (EN) and pin 3 (GND) of JU3. 5) 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 (Figure 1) as follows: • Keeping its leads as short as possible, connect the laser diode to two of the three pads in the cutout portion 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). _______________________________________________________________________________________ 3 Evaluates: MAX3273 Optical Evaluation Component List (continued) Evaluates: MAX3273 MAX3273 Evaluation Kit Adjustment and Control Descriptions (see Quick Start first) COMPONENT • NAME FUNCTION OPTICAL ELECTRICAL JU2 JU7 LATCH JU3 JU8 EN JU14 JU4 Open Loop R9 R37 RMODSET Adjusts the laser modulation current. R2 R12 RBIASMAX Adjusts the laser bias current. In open-loop mode, R2 or R12 adjusts the operating laser bias current. In closed-loop operation, R2 or R12 adjusts the maximum laser bias current limit. R14 R13 RAPCSET For closed-loop operation, R13 or R14 adjusts the monitor diode current level. TP9 TP8 Fail Indicator TTL low level indicates a failure in the APC loop or open-loop operation. D1 D3 Fail Indicator Set APC current, and then increase bias current until LED goes off (LED is illuminated when the APC loop is open and off when the APC loop is closed). Refer to the Design Procedure section of the MAX3273 data sheet. Enables/disables the latching function from the clock input. Active high (shunt across pin 1 and pin 2 of JU2 or JU7 to enable latch). Enables/disables the output currents. Active low (shunt across pin 2 and pin 3 of JU3 or JU8 to enable output currents). Shunt JU4 or JU14 to operate in open-loop mode. 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. Three of these pads (the middle and outside positions) are initially not connected. The other two pads are connected to VCC. Solder the anode and cathode of the monitor photodiode to any two of the three pads that are not connected. Then connect the anode to the MD pin by shorting the corresponding solder jumper (Figure 1). Connect the cathode to VCC by using solder to bridge to an adjacent VCC pad. Note: When performing the following resistance checks, manually set the ohmmeter to a high range to avoid forward-biasing the on-chip ESD protection diodes. 6) Adjust R9, the RMODSET potentiometer, for 10kΩ resistance between TP4 and ground. 7) Adjust R2, the RBIASMAX potentiometer, for 10kΩ resistance between TP1 and ground. 9) Apply a differential input signal (200mVp-p to 1600mVp-p) between J1 and J2 (DATA+ and DATA-) 10) If the latch is enabled, apply a differential clock signal (200mVp-p to 1600mVp-p) between J3 and J4 (CLK+ and CLK-). 11) Attach the laser diode fiber connector to an optical/electrical converter. 12) Power-up the board and adjust the power supply until the voltage between TP14 and ground is +3.3V (VCC). 13) Adjust R2 until the LED, D1, is no longer illuminated. 14) Adjust R9 until the desired optical amplitude is achieved. Optical amplitude can be observed on an oscilloscope connected to an optical/electrical converter. 8) Adjust R14, the RAPCSET potentiometer, for 10kΩ resistance between TP7 and ground. (Refer to the Design Procedure section of the MAX3273 data sheet.) 4 _______________________________________________________________________________________ MAX3273 Evaluation Kit CONFIGURATION 2 TOP OF PC BOARD TOP OF PC BOARD R20 R20 VCC VCC VCC VCC TO-46 CAN LASER/PHOTODIODE PAIR TO-46 CAN LASER/PHOTODIODE PAIR PD SOLDER BRIDGES VCC PD SOLDER BRIDGES VCC VCC VCC TO MD TO MD BOTTOM OF PC BOARD BOTTOM OF PC BOARD CONFIGURATION 3 CONFIGURATION 4 TOP OF PC BOARD TOP OF PC BOARD R20 R20 VCC VCC VCC VCC TO-46 CAN LASER/PHOTODIODE PAIR TO-46 CAN LASER/PHOTODIODE PAIR PD SOLDER BRIDGES VCC Evaluates: MAX3273 CONFIGURATION 1 PD SOLDER BRIDGES VCC VCC VCC TO MD BOTTOM OF PC BOARD TO MD BOTTOM OF PC BOARD Figure 1. Attachment of Laser Diode/Monitor Diode to MAX3273 EV Kit _______________________________________________________________________________________ 5 CLK- J6 CLK+ J5 DATA- J8 DATA+ J7 GND1 VCC1 JU13 C24 0.1µF C23 0.1µF C21 0.1µF C18 0.1µF R28 100Ω R30 100Ω R4 1kΩ RBIASMAX R12 500kΩ C15 0.01µF R5 681Ω RAPCSET R13 100kΩ C40 10µF TP11 VCC 6 TP3 TP8 VCC DATA- DATA+ VCC 24 23 22 TP2 VCC 7 CLK- 5 CLK+ 4 3 2 1 JU10 JU12 C41 0.01µF VCC APCSET JU7 8 LATCH L9 1.2µH 9 21 C16 0.01µF U4 JU8 10 20 19 D3 LED FAIL MAX3273 FAIL GND BIASMAX GND APCFILT2 EN VCC 11 12 15 16 17 18 TP10 VCC R26 2kΩ C37 0.01µF VCC JU9 13 BIAS 14 VCC OUT+ OUT- VCC C30 470pF VCC JU18 MO 4 7 BIAS 1 U3 Figure 2. MAX3273 EV Kit Schematic—Electrical Configuration _______________________________________________________________________________________ VCC JU20 L6 COILCRAFT DO1608C-333 L7 MURATA BLM21A102S L11 MURATA BLM11HA601SG L10 MURATA BLM11HA601SG L12 MURATA BLM21A102S BIAS JU5 TP12 R46 5.11Ω TP13 D4 DIOS1A MAX495 VMODN 3 2 VCC R47 392Ω C14 0.1µF RMODSET R37 100kΩ TP22 6 C45 0.01µF VCC C31 0.01µF R29 0Ω JU11 VCC Q2 FMMT591A JU4 MO R17 110Ω MD R38 49.9Ω APCFILT1 MODSET 6 GND C27 0.056µF C13 10µF R22 49.9Ω R51 C28 0.056µF 24.9Ω C32 0.01µF JU19 R23 OPEN R25 OPEN VMOON J9 OUT+ Evaluates: MAX3273 MAX3273 Evaluation Kit CLK- J4 CLK+ J3 DATA- J2 DATA+ J1 GND2 C6 0.1µF C5 0.1µF C4 0.1µF C3 0.1µF JU6 R10 100Ω R11 100Ω R1 1kΩ RBIASMAX R2 500kΩ C1 0.01µF R15 681Ω RAPCSET R14 100kΩ 6 TP7 TP9 DATA- DATA+ VCC 24 23 22 VCC2 7 CLK- VCC 5 CLK+ 4 3 2 1 JU16 TP1 C20 0.01µF JU17 VCC2 C19 10µF VCC2 JU2 8 APCSET LATCH TP14 9 U1 21 D1 LED C2 0.01µF JU3 10 20 19 11 12 VCC2 FAIL MAX3273 FAIL GND BIASMAX GND APCFILT2 EN L4 1.2µH APCFILT1 MODSET VCC2 15 16 17 TP4 VCC R7 2kΩ C9 0.01µF RMODSET R9 100kΩ L1 COILCRAFT DO1608C-333 L3 MURATA BLM11HA601SG L2 MURATA BLM11HA601SG VCC2 TP5 C10 0.01µF R8 0Ω VCC2 JU15 13 VCC BIAS 14 OUT+ OUT- 18 VCC2 C8 470pF JU14 VCC R16 110Ω MD GND VCC2 VCC2 TP6 C11 0.01µF R3 75Ω C7 0.056µF R6 24.9Ω VCC2 L5 MURATA BLM11HA601SG R18 OPEN C12 OPEN 584 585 586 C38 0.01µF R20 20Ω VCC2 6 4 C22 0.01µF VCC2 C36 C17 0.01µF 100pF VCC2 (REFER TO FIGURE 1) (REFER TO FIGURE 1) 2 3 1 LASER D2 PHOTODIODE 5 581 582 583 Evaluates: MAX3273 R21 49.9Ω MAX3273 Evaluation Kit Figure 3. MAX3273 EV Kit Schematic—Optical Configuration _______________________________________________________________________________________ 7 Evaluates: MAX3273 MAX3273 Evaluation Kit 1.0" Figure 4. MAX3273 EV Kit Component Placement Guide— Component Side 8 1.0" Figure 5. MAX3273 EV Kit PC Board Layout—Component Side _______________________________________________________________________________________ MAX3273 Evaluation Kit Evaluates: MAX3273 1.0" 1.0" Figure 6. MAX3273 EV Kit PC Board Layout—Ground Plane Figure 7. MAX3273 EV Kit PC Board Layout—Power Plane _______________________________________________________________________________________ 9 Evaluates: MAX3273 MAX3273 Evaluation Kit 1.0" Figure 8. MAX3273 EV Kit PC Board Layout—Solder Side 10 ______________________________________________________________________________________ MAX3273 Evaluation Kit THIS IS A 50Ω CONTROLLED-IMPEDANCE BOARD. THE LAYER PROFILE IS BASED ON THE FOLLOWING ASSUMPTIONS: 1) DIELECTRIC MATERIAL IS FR-4 WITH A DELECTRIC CONSTANT OF ~4.8 2) 1/2oz COPPER 3) DIFFERENTIAL 11.5 TRACE 10MIL SPACE; SINGLE ENDED 18.4MIL 11.5MIL 11.5MIL 10MIL PREPREG CORE AS NEEDED 10MIL PREPREG Figure 9. MAX3273 EV Kit PC Board Layer Profile 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 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. Evaluates: MAX3273 LAYER PROFILE