19-2867; Rev 0; 5/03 MAX5888 Evaluation Kit Ordering Information PART TEMP RANGE MAX5888EVKIT 0°C to +70°C Features ♦ Quick Dynamic Performance Evaluation ♦ LVDS Compatible ♦ SMA Coaxial Connectors for Clock Input and Analog Output ♦ 50Ω Matched Clock Input and Analog Output Signal Lines ♦ Single-Ended to Differential Clock-Signal Conversion Circuitry ♦ Differential Current Output to Single-Ended Voltage Signal Output Conversion Circuitry ♦ Full-Scale Current Output Configured for 20mA IC PACKAGE ♦ External 1.25V Reference Source Available 68 QFN-EP* ♦ Fully Assembled and Tested *EP = Exposed pad. ♦ Evaluates the 16-Bit MAX5888, 14-Bit MAX5887, and 12-Bit MAX5886 DACs Component List DESIGNATION C1 C2–C15 C16, C28 C17, C20, C23 DESIGNATION QTY 0 Not installed, ceramic capacitor (0603) R1–R4 4 100Ω ±0.1% resistors (0603) R5 1 100Ω ±1% resistor (0603) R6, R8, R9 0 Not installed, resistors (0603) 14 0.1µF ±10%, 10V X5R ceramic capacitors (0402) TDK C1005X5R1A104KT or Taiyo Yuden LMK105BJ104KV R7 1 2kΩ ±1% resistor (0603) R10, R11 2 24.9Ω ±1% resistors (0402) R12, R13 2 0Ω ±5% resistors (0402) 0 Not installed, ceramic capacitors (0805) L1–L4 4 Ferrite bead cores (4532) Panasonic EXC-CL-4532U1 T1, T3 2 3 47µF ±10%, 6.3V tantalum capacitors (B) AVX TAJB476K006R or Kemet T494B476K006AS Transformers Mini-Circuits ADTL1-12 T2 1 1:1 balun transformer Coilcraft TTWB3010-1 CLK, OUT 2 SMA PC-mount vertical connectors 2 Scope probe connectors Tektronix 131-4244-00 (100 quantity) QTY DESCRIPTION 10µF ±10%, 10V tantalum capacitors (A) AVX TAJA106K010R or Kemet T494A106K010AS C18, C21, C24, C26 4 C19, C22, C25, C27 4 1µF ±10%, 10V X5R ceramic capacitors (0603) TDK C1608X5R1A105KT J1, J2 2 2 x 20-pin surface-mount headers (0.1in) Samtec TSM-120-02-S-MT JU1–JU5 5 2-pin headers OUT+, OUT- DESCRIPTION TP1, TP2, TP3 3 PC test points, black TP4 U1 1 1 PC test point, red MAX5888EGK (68-pin QFN-EP) U2 1 1.25V voltage reference (8-pin SO) Maxim MAX6161AESA None 5 Shunts (JU1–JU5) None 1 MAX5888 PC board ________________________________________________________________ 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: MAX5886/MAX5887/MAX5888 General Description The MAX5888 evaluation kit (EV kit) is a fully assembled and tested circuit board that contains all the components necessary to evaluate the performance of the MAX5888 16-bit, 500Msps, current-output, digital-toanalog converter (DAC). The EV kit requires low-voltage differential-signaling (LVDS)-compatible data input, a single-ended clock input, and 3.3V power supplies for simple board operation. The MAX5888 EV kit may also be used to evaluate the MAX5887 (14-bit) and MAX5886 (12-bit) DACs. Evaluates: MAX5886/MAX5887/MAX5888 MAX5888 Evaluation Kit Component Suppliers SUPPLIER PHONE FAX WEBSITE AVX 843-946-0238 843-626-3123 www.avxcorp.com Coilcraft 847-639-6400 847-639-1469 www.coilcraft.com Kemet 864-963-6300 864-963-6322 www.kemet.com Mini-Circuits 718-934-4500 718-934-7092 www.minicircuits.com Panasonic 714-373-7366 714-737-7323 www.panasonic.com Samtec 812-944-6733 812-948-5047 www.samtec.com Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com TDK 847-803-6100 847-390-4405 www.component.tdk.com Note: Please indicate that you are using the MAX5888 when contacting these component suppliers. Quick Start Recommended equipment: • Three 3.3VDC power supplies • Function generator with low phase noise and low jitter for clock input (e.g., HP 8662A) • 16-bit digital pattern generator for LVDS data inputs (e.g., Agilent 81250) • Spectrum analyzer (e.g., Rohde & Schwartz FSEA30) • Voltmeter The MAX5888 EV kit is a fully assembled and tested surface-mount board. Follow the steps below for board operation. Do not turn on power supplies or enable signal generators until all connections are completed: 1) Verify that no shunts are installed across jumpers JU1, JU2 (DAC uses the 1.2V internal voltage reference), and JU3 (DAC in normal operation mode). 2) Verify that a shunt is installed across jumper JU4. 3) Verify that no shunt is installed across jumper JU5. 4) Synchronize the digital pattern generator (HP 81250) to the clock function generator (HP 8662A). 5) Connect the clock function signal generator to the CLK SMA connectors on the EV kit. 6) Verify that the 16-bit digital pattern generator is programmed for LVDS outputs. 7) Connect the digital pattern generator output to the input header connectors J1 and J2 on the EV kit board. The input header pins are labeled for proper connection with the digital pattern generator (i.e., connect the positive rail of bit 0 to the header pin labeled B0P and complementary negative rail to the header pin labeled B0N, etc.). 2 8) Connect the spectrum analyzer to the OUT SMA connector. 9) Connect a 3.3V power supply to VDD_CK. Connect the ground terminal of this supply to GND_CK. 10) Connect a 3.3V power supply to DVDD. Connect the ground terminal of this supply to DGND. 11) Connect a 3.3V power supply to AVDD. Connect the ground terminal of this supply to AGND. 12) Turn on the three power supplies. 13) With a voltmeter verify that 1.2V is measured at the VREF PC board pad on the EV kit. 14) Enable the clock function generator and the digital pattern generator. Set the clock function generator output power to 10dBm and the frequency (fCLK) to less than or equal to 500MHz. 15) Use the spectrum analyzer to view the MAX5888 output spectrum or view the output waveform using an oscilloscope. Detailed Description The MAX5888 EV kit is designed to simplify the evaluation of the MAX5888 16-bit, 500Msps, current-output DAC. The MAX5888 requires LVDS-compatible data inputs, differential clock input signals, a 1.2V reference voltage, and 3.3V power supplies for simple board operation. The MAX5888 EV kit provides header connectors to easily interface with an LVDS pattern generator, circuitry to convert the differential current outputs to a singleended voltage signal, and circuitry to convert a usersupplied single-ended clock signal to a differential clock signal required by the DAC. The EV kit circuit includes different options for supplying a reference voltage to the DAC. The EV kit circuit can operate with a single 3.3V power supply, but also supports the use of _______________________________________________________________________________________ MAX5888 Evaluation Kit Power Supplies The MAX5888 EV kit can operate from a single 3.3V power supply connected to the VDD_CK, DVDD, AVDD input power pads and their respective ground pads for simple board operation. However, three separate 3.3V power supplies are recommended for optimum dynamic performance. The EV kit board layout is divided into three sections: digital, analog, and digital clock circuits. Using separate power supplies for each section reduces noise crosstalk and improves the integrity of the output signal. When using separate power supplies, connect each power supply across the DVDD and DGND PC board pads (digital), across the VDD_CK and GND_CK PC board pads (digital clock), and across the AVDD and AGND PC board pads (analog) on the EV kit. LVDS Input Data The MAX5888 EV kit provides two 0.1in 2 x 20 header connectors (J1 and J2) to interface a 16-bit LVDS pattern generator to the EV kit. The header data pins are labeled on the board with the appropriate data bit designation. Use the labels on the EV kit to match the data bits from the LVDS pattern generator to the corresponding data pins on J1 and J2. The positive rail of a bit is labeled BxP (positive) and the complementary rail is labeled BxN (negative) where x is the bit number. Clock Signal The MAX5888 requires a differential clock input signal with minimal jitter. The EV kit circuit provides singleended to differential conversion circuitry. The user must supply a single-ended clock signal at the CLK SMA connector. The clock signal can be either a sine wave or a square wave. For a sine wave, 2VP-P (10dBm) amplitude is recommended and for a square wave greater than a 0.5VP-P signal is recommended. Reference Voltage Options The MAX5888 requires a reference voltage to set the full-scale analog signal voltage output. The DAC contains an internal stable on-chip bandgap reference of 1.2V that can be used by decoupling the REFIO pin. The internal reference can be overdriven by an external reference to enhance accuracy and drift performance or for gain control. The MAX5888 EV kit features three ways to provide a reference voltage to the DAC: internal, on-board external, and user-supplied external reference. Verify that no shunt is connected across jumper JU1 to use the internal reference. The reference voltage can be measured at the VREF pad on the EV kit. The EV kit circuit is designed with an on-board 1.25V temperature-stable external voltage reference source U2 (MAX6161) that can be used to overdrive the internal reference provided by the MAX5888. Install shunts across jumpers JU1 and JU2 to use the on-board external reference. The user can also supply an external voltage reference in the range of 0.125V to 1.25V by connecting a voltage source to the VREF pad and removing the shunts across jumpers JU1 and JU2. See Table 1 to configure the shunts across jumpers JU1 and JU2 and select the source of the reference voltage. Full-Scale Output Current The MAX5888 requires an external resistor to set the full-scale output current. The MAX5888 EV kit full-scale current is set to 20mA with resistor R7. Replace resistor R7 to adjust the full-scale output current. Refer to the Reference Architecture and Operation section in the MAX5888 data sheet to select different values for R7. Differential Output The MAX5888 complementary current outputs are terminated into differential 50Ω resistance to generate voltage signals with amplitudes of 1VP-P differential. The positive and negative rails of the differential signal can be sampled at the OUT+ and OUT- probe connectors. The differential signal is converted into a 50Ω singled-ended signal with balun transformer T2 and can be sampled at the OUT SMA connector. A shunt on jumper JU4 connects the center tap of transformer T2 to AGND, thus enhancing the dynamic performance of the DAC. The single-ended output signal after the transformer generates a -3dBm full-scale output power when terminated into 50Ω. A shunt on jumper JU4 should always be installed for optimum dynamic performance. Table 1. Reference Voltage Selection JU1 AND JU2 SHUNT POSITIONS Installed VOLTAGE REFERENCE MODE External 1.25V reference (U2) connected to REFIO pin Not installed MAX5888 DAC internal 1.2V bandgap reference Not installed User-supplied voltage reference at the VREF pad (0.125V to 1.25V) _______________________________________________________________________________________ 3 Evaluates: MAX5886/MAX5887/MAX5888 three separate 3.3V power supplies by dividing the circuit grounds into digital, analog, and digital clock ground planes that improve dynamic performance. The three ground planes are connected together on the back of the PC board. Evaluates: MAX5886/MAX5887/MAX5888 MAX5888 Evaluation Kit Power-Down The MAX5888 can be powered down or powered up by configuring jumper JU3. In power-down mode, the total power dissipation of the DAC is reduced to less than 1mW. See Table 2 for jumper JU3 configuration. Table 2. Jumper JU3 (Power-Down) SHUNT FUNCTION Installed Power-down mode Not installed Normal operation Segment Shuffling The segment-shuffling function on the MAX5888 improves the high-frequency spurious-free dynamic range (SFDR) at the cost of a slight increase in the DAC’s noise floor. The MAX5888 EV kit provides jumper JU5, which allows the user to enable or disable this function. See Table 3 to configure jumper JU5. Table 3. Segment-Shuffling Mode (Jumper JU5) SHUNT Evaluating the MAX5887 or MAX5886 The MAX5888 EV kit can be used to evaluate the MAX5887 or MAX5886 DACs. The MAX5887 is a 14-bit DAC and the MAX5886 is a 12-bit DAC. Except for the input pins, these DACs are pin-for-pin compatible with the MAX5888. Replace the MAX5888 (U1) with the MAX5887 or the MAX5886 and refer to the respective data sheet to compare the difference in input pins and how to modify the connections between the pattern generator and the EV kit input connectors. Installed Not installed SEL0 PIN SEGMENT-SHUFFLING MODE Connected to DVDD Enabled Connected to DGND with internal pulldown resistor Disabled Board Layout The MAX5888 EV kit is a four-layer board design optimized for high-speed signals. All high-speed signal lines are routed through 50Ω impedance-matched transmission lines. The length of these 50Ω transmission lines is matched to within 40 mils (1mm) to minimize layout-dependent data skew. The board layout separates the analog, digital, and digital clock sections of the circuit for optimum performance. 4 _______________________________________________________________________________________ _______________________________________________________________________________________ CLK 1 GND_CK TP2 2 1 GND_CK 3 J2-37 J2-35 J2-33 J2-4 J2-6 J2-8 J2-5 J2-3 J2-1 J2-36 J2-38 J2-40 R10 24.9Ω 1% AVDD C14 0.1µF JU2 U2 GND_CK GND_CK DVDD OUT N.C. N.C. 1 C24 10µF 2 10V 5 6 7 8 GND_CK 9 8 7 6 5 4 3 2 1 C27 1.0µF JU1 17 15 16 14 13 12 11 10 18 AVDD PD CLKGND VCLK CLKN CLKP CLKGND VCLK DVDD DGND B0N B0P B1N B1P B2N B2P B3N B3P C25 1.0µF VDD_CK TP4 JU3 C8 0.1µF VDD_CK GND_CK C9 0.1µF VDD_CK GND MAX6161 GND N.C. IN N.C. 1 C23 47µF 2 6.3V 4 3 2 1 C28 OPEN R13 0Ω R12 0Ω L2 GND_CK C13 0.1µF C12 0.1µF GND_CK C16 OPEN C22 1.0µF VDD_CK 1 C21 10µF 2 10V R11 4 GND_CK 24.9Ω 1% T3 J2-7 J2-34 6 J2-9 J2-32 J2-30 J2-11 J2-28 J2-13 J2-26 J2-15 J2-24 J2-17 J2-22 J2-19 J2-20 J2-21 J2-18 J2-23 J2-16 J2-25 J2-14 J2-27 J2-12 J2-29 J2-10 J2-31 J2-39 J2-2 J2 1 C20 47µF 2 6.3V VREF 19 C26 10µF 10V C7 0.1µF L4 VREF C2 0.1µF 20 VREF 21 R7 2kΩ 1% 22 23 B4N AVDD 68 B4P AGND 67 B5N REFIO 66 B5P FSADJ DGND DVDD TP1 DVDD 24 AVDD JU4 OUT- C10 0.1µF J1-40 B6N DACREF 65 B6P N.C. 63 J1-1 U1 C15 0.1µF 1 1 6 C1 OPEN 6 R3 100Ω 0.1% 26 5 2 T1 TP3 28 2 OUT 29 C5 0.1µF R8 SHORT R4 100Ω 0.1% R2 100Ω 0.1% T2 1 3 4 3 4 R6 OPEN R5 100Ω 1% 27 MAX5888 R1 100Ω 0.1% R9 SHORT C6 0.1µF 25 DGND AVDD 62 DVDD AGND 64 J1-38 IOUTN L1 60 J1-3 OUT+ 30 AVDD GND_CK C4 0.1µF 31 C3 0.1µF 32 33 AVDD 34 B7N 61 J1-36 DGND J1-34 J1-7 J1-5 B7P AGND 59 J1-32 IOUTP 58 J1-9 57 B8N AVDD 56 B8P AVDD 55 B9N AGND 54 B9P AVDD 53 B10N AGND N.C. N.C. N.C. N.C. SEL0 DGND DVDD B15P B15N B14P B14N B13P B13N B12P B12N B11P B11N 52 B10P N.C. C11 0.1µF C19 1.0µF 35 36 37 38 39 41 40 42 43 44 45 46 47 48 49 50 51 JU6 JU5 DVDD C18 10µF 10V 2 1 AVDD DVDD DVDD J1 C17 47µF 6.3V L3 J1-39 J1-37 J1-35 J1-33 2 1 J1-2 J1-4 J1-6 J1-8 J1-31 J1-10 J1-29 J1-12 J1-27 J1-14 J1-25 J1-16 J1-23 J1-18 J1-21 J1-20 J1-19 J1-22 J1-17 J1-24 J1-15 J1-26 J1-13 J1-28 J1-11 J1-30 AGND AVDD Evaluates: MAX5886/MAX5887/MAX5888 DVDD MAX5888 Evaluation Kit Figure 1. MAX5888 EV Kit Schematic 5 Evaluates: MAX5886/MAX5887/MAX5888 MAX5888 Evaluation Kit Figure 2. MAX5888 EV Kit Component Placement Guide— Component Side Figure 3. MAX5888 EV Kit PC Board Layout—Component Side Figure 4. MAX5888 EV Kit PC Board Layout—Ground Planes Figure 5. MAX5888 EV Kit PC Board Layout—Power Planes 6 _______________________________________________________________________________________ MAX5888 Evaluation Kit Figure 7. MAX5888 EV Kit Component Placement Guide— 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 _____________________ 7 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. Evaluates: MAX5886/MAX5887/MAX5888 Figure 6. MAX5888 EV Kit PC Board Layout—Solder Side