19-2787; Rev 0; 2/03 MAX3940 Evaluation Kit The MAX3940 evaluation kit (EV kit) is an assembled demonstration board that provides electrical evaluation of the MAX3940 10.7Gbps laser driver. The output of the electrical evaluation section is interfaced to an SMA connector that can be connected to a 50Ω terminated oscilloscope. _____________________ Component List DESIGNATION C0, C1, C10, C11 QTY C2, C6 2 C3 1 C4 C5 4 1 1 J1-J7 7 J10, J11, TP1 J12, J13 JU1-JU3, JU5, JU8 3 2 5 JU4, JU6, JU7 3 JU1- JU8 L0 8 1 R0-R2 3 R3 R4 R5 U1 1 1 1 1 None 1 None None 1 1 DESCRIPTION 0.01µF ±10% ceramic capacitors (0402) 30pF chip MIS capacitors Metelics Corporation, 30 mils × 30mils, MC2-S-030-020-020 22µF ±10% tantalum capacitor AVX TAJB226K010 10µF ±10% tantalum capacitor AVX TAJA106K010 0.1µF ±10% ceramic capacitor (0402) Murata GRP155R61A104K SMA connectors, edge mount, EF Johnson 142-0701-851 Test points, Digi-Key 5000K-ND SMB connectors, PC mount 2-pin headers, 0.1in centers Digi-Key S1012-36-ND 3-pin headers, 0.1in centers Digi-Key S1012-36-ND Shunts, Digi-Key S9000-ND 47nH inductor (0402) 2kΩ variable resistors Bourns 3296W-202 4.2kΩ ±1% resistor (0402) 2kΩ ±1% resistor (0402) Not installed MAX3940E/D die MAX3940 EV kit circuit board, rev A MAX3940 EV kit data sheet MAX3940 data sheet _____________________________Features ♦ SMA Connectors for All High-Speed I/Os ♦ Configured for Electrical Operation, No Laser Necessary ♦ Single –5.2V Power-Supply Operation ♦ Fully Assembled and Tested ________________Ordering Information PART MAX3940EVKIT TEMP. RANGE -40°C to +85°C IC PACKAGE Chip on board _______________ Component Suppliers SUPPLIER PHONE FAX AVX 843-444-2863 843-626-3123 Coilcraft 847-639-6400 847-639-1469 Digi-Key 218-681-6674 218-681-3380 EF Johnson 402-474-4800 402-474-4858 Murata 415-964-6321 415-964-8165 Note: Please indicate that you are using the MAX3940 when ordering from these suppliers. ________________ Detailed Description The MAX3940 EV Kit is a fully assembled and factory tested demonstration board that enables testing of all MAX3940 functions. Test Equipment Required • -5.2V power supply with 300mA current capability • Signal-source, 10Gbps minimum capability • Oscilloscope with at least 15GHz performance Test Equipment Interface The data and clock inputs (DATA±, CLK±) are DC-coupled to the SMA connectors, so be sure to set proper commonmode voltages for these inputs. The combination bias and modulation output (OUT) is also DC-coupled to the SMA connector and requires a 50Ω to ground load for proper operation. __________________________________________________________________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: MAX3940 _________________General Description Evaluates: MAX3940 MAX3940 Evaluation Kit _____________________________________________________________________ Quick Start 1) If the data is to be latched, place shunt on JU2 (RTEN) to enable the clock inputs. Otherwise, leave JU2 open. 10) Connect a differential signal source to J2 (DATA+) and J3 (DATA-). Refer to the MAX3940 data sheet to determine voltage levels. 2) Install jumpers on JU5 and JU8. 11) If the latch is enabled, apply a differential clock signal to J4 (CLK+) and J5 (CLK-). Refer to the MAX3940 data sheet to determine voltage levels. 3) Install a jumper on the left “DC” side of JU6. This allows adjustment of MODSET. 4) Install a jumper on the right “DC” side of JU7. This allows adjustment of BIASSET. 5) To use the pulse-width control (PWC) install a jumper on the right side of JU4. To disable PWC place a jumper on the left “GND” side of JU4. 12) Connect a high-bandwidth oscilloscope such as the Tektronix CSA8000 with the 80E01 sampling head to J1 (OUT). 6) Ensure that a jumper is not installed on JU3 to float MODEN and enable modulation. 13) A high-quality SMA attenuator (14dB or 20dB) is required to reduce the signal level for compatibility with the sampling head. The attenuator should be connected directly to the output SMA connector on the EV kit to minimize transmission line reflections. 7) Adjust R1 to the full counter-clockwise position. This will minimize modulation swing. 14) Attach a –5.2V power supply to VEE and GND. Set the current limit to 300mA and power up the board. 8) Adjust R2 to the full clockwise position. minimize bias voltage. This will 15) Adjust R1 clockwise until the desired modulation swing is achieved. 9) Adjust R0 to the approximate center of its adjustment range (if PWC is enabled). 16) Adjust R2 counter-clockwise until the desired bias voltage is achieved. 17) Adjust R0 until the desired pulse width is achieved (if PWC is enabled). _______________________________________ Adjustments and Control Descriptions COMPONENT NAME FUNCTION JU1 PLRT Enables/disables the polarity inversion function. Shunt JU1 to invert the polarity of the output data. Shunting JU1 shorts the PLRT pin to VEE. Leave open for normal operation. JU2 RTEN Enables/disables data retiming. Shunt to enable data retiming. Remove shunt for direct data transmission. JU3 MODEN Enables/disables modulation output. Shunt to disable switching of the data output. When shunted the output goes to the absorbtive (logic 0) state. Remove shunt to enable modulation. R1 RMODSET Adjusts the EAM modulation current. Turn the potentiometer screw clockwise to increase the modulation amplitude (decrease the resistance of MODSET to GND). R2 RBIASSET Adjusts the EAM bias current. Turn the potentiometer screw counter-clockwise to increase bias current (decrease the resistance from BIASSET to GND). R0 RPWC Adjusts the EAM pulse width. Turn the potentiometer screw clockwise to increase the logic 1 width. 2 __________________________________________________________________________________________________ MAX3940 Evaluation Kit Evaluates: MAX3940 Figure 1. MAX3940 EV Kit Schematic _________________________________________________________________________________________________ 3 Evaluates: MAX3940 MAX3940 Evaluation Kit Figure 2. MAX3940 EV Kit Component Placement Guide—Component Side Figure 3. MAX3940 EV Kit PC Board Layout—Ground Plane 4 __________________________________________________________________________________________________ MAX3940 Evaluation Kit Evaluates: MAX3940 Figure 4. MAX3940 EV Kit PC Board Layout—Component Side Figure 5. MAX3872/MAX3874 EV Kit PC Board Layout—Power Plane _________________________________________________________________________________________________ 5 Evaluates: MAX3940 MAX3940 Evaluation Kit Figure 6. MAX3872/MAX3874 EV Kit 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. 6 ______________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.