19-1256; Rev 2; 10/98 MAX2102 Evaluation Kit The board includes RF and LO inputs and I/Q baseband-output connectors, for fast evaluation in a 50Ω environment. The RF and LO input frequency range is 950MHz to 2150MHz. A probe-tip jack is available to examine the prescaler output with a high-impedance probe. ____________________________Features ♦ Simple RF Test Board Offers 50Ω Test Ports for RF and LO Inputs and Baseband Outputs ♦ Direct-Conversion Signal Tuning from 950MHz to 2150MHz, to I/Q Baseband ♦ Input Levels: -69dBm to -19dBm per Carrier ♦ Allows Testing of 50dB Automatic Gain-Control Range ♦ Permits Observation of Dual-Modulus Prescaler Output Component Suppliers SUPPLIER PHONE ♦ Fully Assembled and Tested FAX AVX (803) 946-0690 (803) 626-3123 Panasonic (201) 392-7522 (201) 392-4441 Ordering Information PART TEMP. RANGE BOARD TYPE MAX2102EVKIT-SO 0°C to +70°C Surface Mount Component List DESIGNATION QTY B1–B5 C1, C9 C2, C3, C8, C11 DESCRIPTION 5 Surface-mount bead cores Panasonic EXC-CL3216U 2 47µF, 10V, ±20% electrolytic capacitors Panasonic ECE-V1AA470P 4 0.1µF, 50V (min), 10% ceramic capacitors 6 22pF, 50V (min), 10% ceramic capacitors C10, C12 2 10pF, 50V (min), 10% ceramic capacitors C13, C16 2 10pF, 50V (min), 10% ceramic capacitors C17, C19, C21, C22 4 1000pF, 50V (min), 10% ceramic capacitors C20 1 10µF, 16V, ±20% tantalum capacitor AVX TAJC106M106 C26, C27 2 0.22µF, 50V (min), 10% ceramic capacitors J1, J3 2 BNC connectors C4–C7, C14, C15 DESIGNATION QTY DESCRIPTION J2, J4, J5 3 Edge-mount SMA connectors J6 1 Scope-probe connector JU2, JU3 2 3-pin headers (0.1" centers) Shunts R1, R7 2 47Ω, 5% resistors R3, R13 2 Open R4, R16 2 51Ω, 5% resistors R6 1 2kΩ, 5% resistor R8, R10 2 22Ω, 5% resistors R11, R12 2 56Ω, 5% resistors R15 1 100Ω, 5% resistor R17 1 4.7Ω, 5% resistor U1 1 Maxim MAX2102CWI (28-pin SO) None 1 MAX2102 circuit board None 1 MAX2102 data sheet ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. Evaluates: MAX2102 General Description The MAX2102 evaluation kit (EV kit) simplifies evaluation of the MAX2102 direct-conversion tuner IC for digital DBS applications. Evaluates: MAX2102 MAX2102 Evaluation Kit __________Test Equipment Required • RF-signal generator to generate the RF-carrier signals, with 950MHz to 2150MHz frequency range and -69dBm to -19dBm power range. • RF-signal generator to generate the LO signal, with 950MHz to 2150MHz frequency range at -10dBm. • (Optional) RF balun, such as Anzac H-9, if testing the MAX2102 with a differential LO drive. • Dual-channel digitizing oscilloscope with 50Ω terminated inputs and 100MHz minimum bandwidth for time-domain baseband measurements. In addition, a high-frequency, high-impedance probe is required if monitoring the prescaler. • Network/spectrum analyzer capable of measuring 30kHz to 100MHz signals for frequency-domain baseband measurements. • +5V power supply that can deliver a minimum of 300mA. • Adjustable voltage source that can supply a 1V to 4V range and source and sink 500µA for automatic gain control (AGC). Connections and Setup Ensure that the RF signal generators are disabled, and that the power supplies are off until all connections are made. 1) Connect the +5V power supply to J7 (“VCC”). Connect ground to J8 (“GND”). 2) Ensure that there are no shunts installed at JU2 or JU3. 3) Connect the variable voltage source to the pad labeled “AGC.” Ensure that the voltage source’s ground is connected to J8. 4) Connect an SMA cable from the LO signalgenerator source to SMA connector J4 (LO) on the board. A 6dB attenuator connected in-line between J4 and the cable is recommended to minimize reflections that could affect power-level control on some signal generators. See the section Using a Differential Oscillator Source for information on driving the LO port differentially. 5) Connect an SMA cable from the RF-carrier signalgenerator source to SMA connector J2 (RFIN). A 6dB pad between J2 and the cable is recommended. 6) Connect two cables of equal length from the dualchannel oscilloscope inputs to BNC connectors J1 and J3 (“IOUT,” “QOUT”). Ensure that the oscilloscope inputs are 50Ω. 2 7) Set up the instruments: —Set the RF-carrier signal source to deliver 950MHz at -30dBm at RFIN. Be sure to account for attenuator and cable losses. —Set the LO signal source to deliver 950.125MHz at -10dBm at LO. Be sure to account for attenuator and cable losses. —Set up the oscilloscope to view a 125kHz sine wave at 0.5Vp-p full scale, triggered from either the “IOUT” or “QOUT” signal. 8) Turn on the power supplies and enable the signal generators. 9) Adjust the AGC control voltage until the IOUT and QOUT signals are approximately 0.25Vp-p. Analysis AGC Vary the RF-carrier signal-generator power over the -19dBm to -69dBm range. Use the AGC voltage control (in a 1V to 4V range) to keep the IOUT and QOUT signals in the 0.25Vp-p range. Note (from the EV kit schematic) that the board includes 47Ω resistors (R1, R7) in series with the baseband IOUT and QOUT outputs, which results in a 6dB attenuation with the cable terminated to 50Ω at the oscilloscope. The actual voltage swing per carrier is 0.5Vp-p at the MAX2102’s IOUT and QOUT pins. Vary the LO and RFIN frequency over the 950MHz to 2150MHz range, maintaining 125kHz between RFIN and LO. Observe that over 50dB, AGC range is maintained across the frequency band. Quadrature Accuracy The difference in phase between the IOUT and QOUT baseband signals should be 90°, with Q lagging I if the LO frequency is greater than the RFIN frequency. Using both the oscilloscope’s DELAY measurement function and averaging, determine the quadrature phase mismatch (deviation from 90°). The baseband frequency is 125kHz. At higher baseband frequencies, the delay between IOUT and QOUT becomes more difficult to measure accurately. Additionally, phase error due to small differences in group delay in IOUT and QOUT measurement channels becomes more pronounced. Therefore, low baseband frequencies are suggested when making this measurement. _______________________________________________________________________________________ MAX2102 Evaluation Kit Adjustments and Control Prescaler Jumper JU2 controls prescaler enabling and disabling. The prescaler on the MAX2102 EV kit is configured to be disabled as shipped. In this configuration, there is no short installed on JU2. To enable the prescaler, install a short in the “PSON” position. This connects pin 25 on the MAX2102 to GND. JU3 controls the prescaler divider ratio (modulus). Install a short in the “DIV65” position for divide-by-65 mode, or in the “DIV64” position for divide-by-64 mode. For external control of the prescaler modulus (for example, from an external synthesizer), drive JU3’s center connector directly. Using a Differential Oscillator Source To use a differential LO source, do the following: 1) Remove R16. 3) Connect the RF balun so that LO and LO are driven by complementary signals. Drive the balun input from the LO signal source. Ensure that any unused ports on the balun are terminated with 50Ω terminators. A 6dB attenuator connected in-line between the LO and LO ports and the balun is recommended to minimize reflections, which may affect balun and signal-generator performance. 4) Drive the balun with sufficient power to drive LO and LO with -10dBm each. Be sure to account for losses in the balun, cables, and attenuators. Interface to MAX1002/MAX1003 A/D Converters The MAX2102 EV kit can easily be interfaced to the MAX1002/MAX1003 EV kit, allowing evaluation of the MAX2102 in the digital domain. The MAX1002/ MAX1003 are low-cost, dual, 60Msps/90Msps analogto-digital converters for DBS applications. For most applications, an anti-aliasing lowpass filter is inserted in the signal path between IOUT (MAX2102 EV kit) and IIN+ (MAX1002/MAX1003 EV kit), and another equivalent filter is inserted between QOUT and QIN+. Refer to the MAX2102/MAX2105 data sheet for details on this filter. Using 50Ω filters with BNC connectors is a simple way to implement the necessary filtering. 2) Install J5 (SMA connector), if not already populated. _______________________________________________________________________________________ 3 Evaluates: MAX2102 The quadrature amplitude mismatch is: Amplitude mismatch = 20log (AI / AQ) where AI = IOUT signal amplitude, and AQ = QOUT signal amplitude. Vary the LO and RFIN frequency over the 950MHz to 2150MHz range, maintaining 125kHz between RFIN and LO. Observe that the quadrature phase and gain mismatch remains within the specifications across the band. 4 IOUT J1 VCC BNC QOUT J3 AGC RFIN C4 22pF R7 47Ω C2 0.1µF C1 47µF J8 SMA B1 BNC 47Ω R1 GND VCC J7 J2 C8 0.1µF C9 47µF R3 OPEN C22 1000pF C7 R4 22pF 51Ω B2 C21 1000pF C5 22pF VCC C6, 22pF VCC C20 10µF C11 0.1µF C3 0.1µF VCC 1 2 3 4 5 6 7 8 9 10 11 12 C10 13 10pF 14 C12 10pF R17 4.7Ω VCC B5 VCC MOD IOUT PSOUT GND PSGND VCC GND GND VCC VCC U1 RFIN LO RFIN LO MAX2102 V GND CC AGC GND GND IDC GND IDC QOUT QDC VCC QDC VCC VCC VCC 24 23 22 21 20 19 18 17 16 15 28 27 26 25 C17 1000pF C19 1000pF DIV 65 1 2 R15 100Ω DIV 64 3 C26 0.22µF JU3 C27 0.22µF C13 10pF C16 10pF 2 JU2 B3 C14, 22pF C15, 22pF B4 R6 2k PSON 1 VCC PSOFF 3 R11 56Ω VCC J6 R8 22Ω R16 51Ω R10 R12 22Ω 56Ω PSOUT R13 OPEN J4 J5 SMA SMA LO LO Evaluates: MAX2102 MAX2102 Evaluation Kit Figure 1. MAX2102 EV Kit Schematic _______________________________________________________________________________________ MAX2102 Evaluation Kit Evaluates: MAX2102 1.0" 1.0" Figure 2. MAX2102 EV Kit Component Placement Guide— Component Side Figure 3. MAX2102 EV Kit Component Placement Guide—Solder Side _______________________________________________________________________________________ 5 Evaluates: MAX2102 MAX2102 Evaluation Kit 1.0" Figure 4. MAX2102 EV Kit PC Board Layout—Component Side 6 1.0" Figure 5. MAX2102 EV Kit PC Board Layout—Ground Plane _______________________________________________________________________________________ MAX2102 Evaluation Kit Evaluates: MAX2102 1.0" 1.0" Figure 6. MAX2102 EV Kit PC Board Layout—Power Layer Figure 7. MAX2102 EV Kit PC Board Layout—Solder Side _______________________________________________________________________________________ 7 Evaluates: MAX2102 MAX2102 Evaluation Kit NOTES 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.