general description the max2102 evaluation kit (ev kit) simplifies evalua- tion of the max2102 direct-conversion tuner ic for digi- tal dbs applications. the board includes rf and lo inputs and i/q base- band-output connectors, for fast evaluation in a 50 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 50 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 ? fully assembled and tested evaluates: max2102 max2102 evaluation kit ________________________________________________________________ maxim integrated products 1 qty description b1?5 5 c1, c9 2 c2, c3, c8, c11 4 0.1?, 50v (min), 10% ceramic capacitors c4?7, c14, c15 6 c10, c12 2 10pf, 50v (min), 10% ceramic capacitors c13, c16 2 c17, c19, c21, c22 4 c26, c27 2 j1, j3 2 bnc connectors 22pf, 50v (min), 10% ceramic capacitors 47?, 10v, ?0% electrolytic capacitors panasonic ece-v1aa470p surface-mount bead cores panasonic exc-cl3216u supplier phone fax avx (803) 946-0690 (803) 626-3123 designation 10pf, 50v (min), 10% ceramic capacitors 1000pf, 50v (min), 10% ceramic capacitors 0.22?, 50v (min), 10% ceramic capacitors component list ordering information component suppliers part MAX2102EVKIT-SO 0? to +70? temp. range board type surface mount 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. designation qty description j2, j4, j5 3 edge-mount sma connectors 3-pin headers (0.1" centers) r1, r7 2 47 , 5% resistors r3, r13 2 open r4, r16 2 51 , 5% resistors r6 1 2k , 5% resistor r8, r10 2 22 , 5% resistors r11, r12 2 56 , 5% resistors r15 1 100 , 5% resistor r17 1 4.7 , 5% resistor u1 1 maxim max2102cwi (28-pin so) none 1 max2102 data sheet ju2, ju3 2 shunts none 1 max2102 circuit board c20 1 10?, 16v, ?0% tantalum capacitor avx tajc106m106 j6 1 scope-probe connector panasonic (201) 392-7522 (201) 392-4441 19-1256; rev 2; 10/98
evaluates: max2102 max2102 evaluation kit 2 _______________________________________________________________________________________ __________ t est equipment requir ed rf-signal generator to generate the rf-carrier sig - nals, 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 50 termi - nated 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 500 a 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 (?cc?. connect ground to j8 (?nd?. 2) ensure that there are no shunts installed at ju2 or ju3. 3) connect the variable voltage source to the pad labeled ?gc.?ensure that the voltage source? ground is connected to j8. 4) connect an sma cable from the lo signal- generator 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 driv- ing the lo port differentially. 5) connect an sma cable from the rf-carrier signal- generator source to sma connector j2 (rfin). a 6db pad between j2 and the cable is recom - mended. 6) connect two cables of equal length from the dual- channel oscilloscope inputs to bnc connectors j1 and j3 (?out,??out?. ensure that the oscillo - scope inputs are 50 . 7) set up the instruments: ?et the rf-carrier signal source to deliver 950mhz at -30dbm at rfin. be sure to account for attenuator and cable losses. ?et the lo signal source to deliver 950.125mhz at -10dbm at lo. be sure to account for attenua- tor and cable losses. ?et up the oscilloscope to view a 125khz sine wave at 0.5vp-p full scale, triggered from either the ?out?or ?out?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 sig - nals in the 0.25vp-p range. note (from the ev kit schematic) that the board in- cludes 47 resistors (r1, r7) in series with the base - band iout and qout outputs, which results in a 6db attenuation with the cable terminated to 50 at the oscilloscope. the actual voltage swing per carrier is 0.5vp-p at the max2102? 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 main - tained 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? delay measurement function and averaging, determine the quadrature phase mismatch (deviation from 90 ). the baseband frequency is 125khz. at higher base - band 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 measure - ment.
evaluates: max2102 max2102 evaluation kit _______________________________________________________________________________________ 3 the quadrature amplitude mismatch is: amplitude mismatch = 20log (a i / a q ) where a i = iout signal amplitude, and a q = 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. adjustments and contr ol 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 ?son?position. this connects pin 25 on the max2102 to gnd. ju3 controls the prescaler divider ratio (modulus). install a short in the ?iv65?position for divide-by-65 mode, or in the ?iv64?position for divide-by-64 mode. for external control of the prescaler modulus (for exam - ple, from an external synthesizer), drive ju3? center connector directly. using a differential oscillator source to use a differential lo source, do the following: 1) remove r16. 2) install j5 (sma connector), if not already populated. 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 50 ter- minators. 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. inter face to max1002/max1003 a/d conver ters 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 analog- to-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 50 filters with bnc connectors is a simple way to implement the necessary filtering.
evaluates: max2102 max2102 evaluation kit 4 _______________________________________________________________________________________ max2102 u1 v cc mod psout psgnd gnd v cc lo lo v cc gnd idc idc qdc qdc 1 2 3 4 5 6 7 8 9 10 11 12 13 14 v cc pson psoff ju2 div 65 b5 div 64 ju3 j6 r8 22 w j4 sma j5 sma r10 22 w b4 1 2 3 1 2 3 c19 1000pf c21 1000pf c20 10 m f c3 0.1 m f c12 10pf c16 10pf r12 56 w r13 open r16 51 w r11 56 w c14, 22pf r15 100 w r6 2k r17 4.7 w c17 1000pf iout gnd v cc gnd v cc rfin rfin gnd agc gnd gnd qout v cc 28 psout lo lo c15, 22pf 27 26 25 24 23 22 21 20 19 18 17 c13 10pf c27 0.22 m f c26 0.22 m f 16 15 vcc vcc vcc b3 vcc vcc j7 j8 vcc vcc b2 vcc vcc gnd iout rfin agc qout j1 bnc r1 b1 j2 j3 bnc r7 47 w 47 w c1 47 m f c2 0.1 m f c6, 22pf c22 1000pf c7 22pf c5 22pf c8 0.1 m f c9 47 m f c11 0.1 m f c10 10pf c4 22pf r3 open r4 51 w sma vcc figure 1. max2102 ev kit schematic
evaluates: max2102 max2102 evaluation kit _______________________________________________________________________________________ 5 1.0" figure 2. max2102 ev kit component placement guide component side 1.0" figure 3. max2102 ev kit component placement guide?older side
evaluates: max2102 max2102 evaluation kit 6 _______________________________________________________________________________________ 1.0" figure 4. max2102 ev kit pc board layout?omponent side 1.0" figure 5. max2102 ev kit pc board layout?round plane
evaluates: max2102 max2102 evaluation kit _______________________________________________________________________________________ 7 1.0" figure 6. max2102 ev kit pc board layout?ower layer 1.0" figure 7. max2102 ev kit pc board layout?older side
evaluates: max2102 max2102 evaluation kit maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it 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. notes
|
