MAX3736EVKIT

MAX3736 Evaluation Kit Evaluates: MAX3736 General Description The MAX3736 evaluation kit (EV kit) is an assembled demonstration board that provides complete optical evaluation of the MAX3736 3.3V multirate laser driver. The EV kit is composed of an optical test circuit. The output of the optical evaluation section is configured for attachment to a laser/monitor diode that is configured in the standard four-lead laser connection on BOSA packages. Features ● Single +3.3V Power-Supply Operation ● AC-Coupling Provided On-Board ● Allows Optical Evaluation ● Proven PCB Layout ● Fully Assembled and Tested Ordering Information appears at end of data sheet. Optical Evaluation Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION C1, C11, C15, C16, C20 5 0.1µF ±10% ceramic capacitors (0402) R1, R2 2 1.5kΩ ±5% resistors (0402) 1 75Ω ±5% resistor (0402)* 0 Not installed, ceramic capacitors (0402) R3 C2–C4 R4, R18 2 1.0kΩ ±1% resistors (0402) C5, C6 2 220pF ±10% ceramic capacitors (0402)* R15, R17 2 20kΩ variable resistors R21 1 10Ω ±5% resistor (0402) C7 1 1µF ±10% ceramic capacitor (0805) R22 1 24Ω ±5% resistor (0402)* 1 15Ω ±5% resistor (0402) 2 0.01µF ±5% ceramic capacitors (0402) R23 C17, C23 U2 1 3.3V multirate laser driver (16 TQFN-EP*) Maxim MAX3736ETE+ — 3 Shunts 1 PCB: MAX3736 EVALUATION KIT REV C D1 0 Not installed, user-supplied laser J1, J2 2 SMA connectors, tab contact J8, J10, TP1–TP10 12 Test points JU1, JU2, JU13 3 2-pin headers, 0.1in centers 2 Ferrite beads (0402) Murata BLM15HG102 L1, L3 — *EP = Exposed pad. *These components are part of the compensation network, which can reduce overshoot and ringing. Ringing due to parasitic series inductance of the laser can be eliminated with R22/R3 and C6 /C5. Starting values for most coaxial lasers is R3 = 75Ω in series with C5 = 220pF and R22 = 24Ω in series with C6 = 220pF. These values should be experimentally adjusted until the optical eye diagram is optimized. Component Supplier SUPPLIER Murata Electronics North America, Inc. PHONE 770-436-1300 WEBSITE www.murata-northamerica.com Note: Indicate that you are using the MAX3736 when contacting this component supplier. 19-6510; Rev 0; 11/12 MAX3736 Evaluation Kit QuickStart Procedure For optical evaluation of the device, configure the EV kit as follows: 1) To enable the outputs, connect DIS to GND by placing a shunt across jumper JU13. 2) The EV kit is designed to allow connection to a typical BOSA-packaged laser. Connect the laser with monitor diode (Figure 1) as follows: Keeping its leads as short as possible, connect the laser diode to the appropriate pads in the cut-out portion on the top (component) side of the PCB. 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. 3) Adjust R17, the RMODSET potentiometer, for maximum resistance (≈20kΩ) between TP7 and ground. This sets the modulation current to a low value (< 10mA). Refer to the Design Procedure section in the MAX3736 IC data sheet. 4) Apply a differential input signal (200mVP-P to 2400mVP-P) between SMA connectors J1 and J2 (IN+ and IN-). Evaluates: MAX3736 6) Connect a 3.3V supply between J8 (VCC) and J10 (GND). Set the current limit to 200mA and power on the device. 7) Adjust R15 (RBIASSET) until the desired average optical power is achieved. 8) The BIAS current can be monitored at TP8 (VBC_MON) using the following equation: IBIAS = VBC_MON 1000Ω × 85 Note: If the voltage at TP8 exceeds 1.39V, the BC_MON pin goes out of regulation. 9) Adjust R17 (RMODSET) until the desired optical amplitude is achieved. Optical amplitude can be observed on an oscilloscope connected to an optical-to-electrical converter. Laser overshoot and ringing can be improved by appropriate selection of R3, R21–R23, C5, and C6, as described in the Design Procedure section in the MAX3736 IC data sheet. Note: External DACs can be used to control the bias and modulation current. To do this, remove shunts from jumpers JU1 and JU2 to disconnect potentiometers R15 (RBIASSET) and R17 (RMODSET). Connect the DAC outputs to TP6 (BIASSET) and TP7 (MODSET). 5) Attach the laser diode fiber connector to an optical-toelectrical converter. Table 1. Adjustment and Control Descriptions (see the Quick Start section first) DESIGNATION NAME DESCRIPTION JU13 DIS Enables/disables the output currents. Active low (shunt across JU13 to enable output currents). R15 RBIASSET Adjusts the bias current. R17 RMODSET Adjusts the laser modulation current. TP8 BC_MON TP8 offers a connection to probe the BC_MON current through a 1kΩ resistor to ground. This allows the bias current to be determined as IBIAS = VBC_MON/1000Ω x 85. TP9 BIAS TP10 MD www.maximintegrated.com TP9 allows the voltage at the BIAS pin to be monitored. TP10 offers a connection to probe the monitor diode current through a 1kΩ resistor to ground. The current can be determined as IMD = VMD/1000Ω. Maxim Integrated │  2 MAX3736 Evaluation Kit Evaluates: MAX3736 MAX3736 TOSA CASE LASER DIODE CATHODE LASER DIODE ANODE/ MONITOR DIODE CATHODE MONITOR DIODE ANODE Figure 1. Attachment of Packaged Laser to the MAX3736 EV Kit JU13 VCC 2 3 J2 IN- VCC C16 0.1µF 4 R15 20kΩ GND GND OUT+ MAX3736 VCC JU1 C2 OPEN OUT- IN- TP6 BIASSET VCC 5 6 7 8 R1 1.5kΩ 12 R3 75Ω L1 FERRITE BEAD R23 15Ω C1 0.1µF 11 C3 OPEN 10 VCC R21 10Ω 9 C20 0.1µF TP10 MD R22 24Ω C6 220pF TP9 BIAS R4 1.0kΩ L3 FERRITE BEAD R2 1.5kΩ TP7 MODSET TP8 BC_MON JU2 MODSET VCC VCC U2 IN+ C17 0.01µF BIASSET VCC VCC BIAS 1 BC_MON C15 0.1µF 13 MODSET J1 IN+ 14 C5 220pF BIASSET C23 VCC 0.01µF 15 DIS 16 VCC C4 R17 OPEN 20kΩ R18 1.0kΩ TP2 J8 3.3V J10 GND C7 1µF TP3 TP1 TP4 TP5 VCC C11 0.1µF Figure 2. MAX3736 EV Kit Schematic www.maximintegrated.com Maxim Integrated │  3 MAX3736 Evaluation Kit Figure 3. MAX3736 EV Kit Component Placement Guide— Component Side www.maximintegrated.com Evaluates: MAX3736 Figure 4. MAX3736 EV Kit PCB Layout—Component Side Maxim Integrated │  4 MAX3736 Evaluation Kit Figure 5. MAX3736 EV Kit PCB Layout—Ground Plane www.maximintegrated.com Evaluates: MAX3736 Figure 6. MAX3736 EV Kit PCB Layout—Power Plane Maxim Integrated │  5 MAX3736 Evaluation Kit Evaluates: MAX3736 Figure 7. MAX3736 EV Kit PCB Layout—Solder Side www.maximintegrated.com Maxim Integrated │  6 MAX3736 Evaluation Kit Evaluates: MAX3736 Ordering Information PART TYPE MAX3736EVKIT EV Kit www.maximintegrated.com Maxim Integrated │  7 MAX3736 Evaluation Kit Evaluates: MAX3736 Revision History REVISION NUMBER REVISION DATE 0 11/12 DESCRIPTION Initial release PAGES CHANGED — For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. ©  2012 Maxim Integrated Products, Inc. │  8