general description the MAX2057 evaluation kit (ev kit) simplifies evalua- tion of the MAX2057 general-purpose, high-perfor- mance, variable-gain amplifier with analog gain control. the ev kit is fully assembled and tested at the factory. standard 50 ? sma connectors are included at the input and output of the ev kit to allow quick and easy evaluation on the test bench. this data sheet provides a list of equipment required to evaluate the device, a straightforward test procedure to verify functionality, a circuit schematic for the kit, a bill of materials (bom) for the kit, and artwork for each layer of the pc board. features ? analog gain control ? up to 42db gain-control range ? 1700mhz to 2500mhz frequency range ? fully assembled and tested ? input and output internally matched to 50 ? over entire band of operation ? 50 ? sma inputs and outputs for easy testing of all MAX2057 features evaluates: MAX2057 MAX2057 evaluation kit ________________________________________________________________ maxim integrated products 1 19-3551; rev 0; 1/05 component list for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. ordering information component suppliers part temp range ic package MAX2057evkit -40? to +85? 36 thin qfn-ep* * ep = exposed paddle. designation qty description c1, c3, c5, c7, c10 4 22pf 5%, 50v c0g ceramic capacitors (0402) murata grp1555c1h220j c2, c4, c6, c8, c9 5 1000pf ?0%, 50v x7r ceramic capacitors (0402) murata grp155r71h102k c11, c12, c16 0 not installed (0603) c13, c14, c15 3 0.1? ?0%, 16v x7r ceramic capacitors (0603) murata grm188r71c104k c17 0 0.75pf ?.1pf, 50v c0g ceramic capacitor (0402) murata grp1555c1hr75b j1?5 5 pc-board edge-mount sma rf connectors (flat-tab launch) johnson 142-0741-856 r1 1 1.2k ? ?% resistor (0402) designation qty description r2 1 2k ? ?% resistor (0402) r3, r4 2 0 ? resistors (0402) tp1 1 large test point for 0.062in pc board (red) mouser 151-107 or equivalent tp2 1 large test point for 0.062in pc board (black) mouser 151-103 or equivalent u1 1 analog vga ic (36-pin, 6mm x 6mm thin qfn-ep) maxim MAX2057etx note: u1 has an exposed paddle conductor that requires it to be solder attached to a grounded pad on the pc board to ensure a proper electrical/thermal design. supplier phone website johnson 507-833-8822 www.johnsoncomponents.com murata 770-436-1300 www.murata.com
evaluates: MAX2057 quick start the MAX2057 ev kit is fully assembled and factory tested. follow the instructions in the connections and setup section for proper device evaluation. test equipment one dc power supply capable of supplying 5v and 0.3a one dc power supply that can be adjusted from 1v to 4.5v for gain control two digital multimeters (dmm) to monitor v cc and i cc , if desired hp 8648 (or equivalent) signal source hp 8561e (or equivalent) spectrum analyzer hp 8753d (or equivalent) network analyzer to mea- sure return loss and gain over frequency (optional) connections and setup this section provides a step-by-step guide to testing the basic functionality of the ev kit. to prevent damaging the device, do not turn on dc power or rf signal genera- tors until all connections are made. do not apply vcntl without v cc present (see the vcntl section). testing the supply current 1) connect 50 ? terminations to j1 and j2. 2) with its output disabled, set the voltage on one of the dc supplies to +5.0v (through a low internal resistance ammeter, if desired) and connect to the +5.0v (tp1) and gnd (tp2) terminals on the ev kit. if the power supply has a current-limiting feature, set the current limit to 250ma. 3) with its output disabled, set the voltage on the sec- ond dc supply to 1v and connect to the gain-control connector vcntl (j3) on the ev kit. this configures the device for its maximum gain setting. if the power supply has a current-limiting feature, set the current limit to 1ma. 4) enable the v cc supply, then enable the gain-control supply; the v cc supply current should read approxi- mately 180ma. testing the power gain 1) with its supply output disabled, set the voltage on one of the dc supplies to +5.0v (through a low internal resistance ammeter, if desired) and connect to the +5.0v (tp1) and gnd (tp2) terminals on the ev kit. if available, set the current limit to 250ma. 2) with its supply output disabled, set the voltage on the other dc supply to 1v and connect to the gain-control connector vcntl (j3) on the ev kit. if available, set the current limit to 1ma. 3) with the generator output disabled, connect the rf signal generator to j1. set the generator to a 2100mhz output frequency, and set the power level to -12dbm. 4) connect the spectrum analyzer to j2. set the spec- trum analyzer to a center frequency of 2100mhz and a total span of 1mhz. set the reference level on the spectrum analyzer to +10dbm. 5) enable the v cc supply. next, enable the gain-control supply. finally, enable the rf generator? output. a 2100mhz signal with a magnitude of approximately 3dbm should be displayed on the spectrum analyzer. be sure to account for external cable losses. 6) vary the gain-control supply voltage between +1.0v and +4.5v. the output power should vary by approximately 21db. 7) gain can also be determined with a network analyzer. this has the advantage of displaying gain over a swept frequency band, in addition to displaying input and output return loss. refer to the network analyzer manufacturer? user manual for setup details (optional). detailed description figure 1 shows the schematic for the MAX2057 ev kit. c1, c3, c5, and c7 are dc-blocking capacitors for the in_a, in, amp_in, and out pins. to reduce the possi- bility of noise pickup from the power supply, capacitors c2, c4, c6, c8, c9, c10, c13, c14, and c15 are used to decouple v cc . resistors r1 and r2 are used to bias the amplifier? first and second stages, respectively. current-setting resistors the MAX2057 amplifier section is a two-stage design whose input stage current is set by the external resistor r1, while the output stage current is set by resistor r2. these resistors were optimized at the factory to pro- duce the highest oip3 for a given current. the current of the device can be reduced by increasing these resistor values (see the modifying the ev kit section), but linearity performance degrades. MAX2057 evaluation kit 2 _______________________________________________________________________________________
vcntl the vcntl pin is used to control the gain of the amplifi- er. the nominal operating range for the vcntl pin is from 1v to 4.5v. limiting vcntl to this range ensures reliability of the device. due to on-chip esd diodes, do not apply vcntl without v cc (+5v) present. if this con- dition is unavoidable, then change r4 on the ev kit to a resistor no smaller than 200 ? . this resistor will limit the current into the vcntl pin for cases where v cc is grounded or left open. modifying the ev kit increasing the value of the external current-setting resistors, r1 (first amp stage) and r2 (second amp stage), can reduce the current draw of the amplifier section of the device. doubling the values of each of these external resistors cuts the dc current drain approximately in half but at the expense of approxi- mately 4.6db lower oip3. since the linearity of the amplifier is set by the cascaded performance of the two amplifier stages, one must be careful to balance the current distribution of the two stages to optimize oip3 at the lowest current. the MAX2057 ev kit has been designed and assembled to add the flexibility of measuring the device in different configurations. the kit has been assembled to cascade one attenuator section followed by the output amplifier. some other configurations can be set as follows. configuration a) to use two attenuators followed by an output amplifier: move capacitor c3 on the ev kit to con- nect pin 2 trace to pin 35 trace of the ic. apply the rf input signal to sma j4 and take the output signal from sma j2. configuration b) to use only the attenuator between ic pins 2 and 8: move capacitor c3 to connect the pin 2 trace of the ic to the trace of connector j1. apply the rf input signal to sma j4 and take the output signal from sma j1. configuration c) to use only the attenuator between ic pins 35 and 29: move capacitor c5 to connect the pin 29 trace of the ic to the trace of connector j5. apply the rf input signal to sma j1 and take the output signal from sma j5. configuration d) to use only the amplifier: move capaci- tor c5 to connect the pin 26 trace of the ic to the trace of connector j5. apply the rf input signal to sma j5 and take the output signal from sma j2. configuration e) to insert a function between one attenu- ator and an output amplifier, configure the board for both configuration b and d. insert the desired function between sma connectors j1 and j5. apply the input sig- nal to sma j4 and take the output signal from sma j2. layout considerations the MAX2057 evaluation boards can be used as a guide for board layout. pay close attention to thermal design and placement of components on the pc board. the exposed paddle (ep) on the MAX2057 package conducts heat away from the die and provides a low- impedance electrical connection. the ep must be attached to the pc board ground plane with a low ther- mal and electrical impedance contact. ideally, this is provided by soldering the backside package contact directly to a metal ground plane on the pc board. alternatively, the ep can be connected to a ground plane using an array of plated vias directly below the ep. the MAX2057 ev kit uses nine evenly spaced, 0.016in-diameter, plated through holes to connect the ep to the lower ground planes. evaluates: MAX2057 MAX2057 evaluation kit _______________________________________________________________________________________ 3
evaluates: MAX2057 MAX2057 evaluation kit 4 _______________________________________________________________________________________ 36 35 34 33 32 31 30 29 28 10 11 12 13 14 15 16 17 18 1 2 3 4 5 6 7 8 9 27 26 25 24 23 22 21 20 19 gnd in gnd gnd v cc gnd gnd attn_out gnd MAX2057 u1 exposed p addle gnd v cntl gnd v cc gnd r set1 v cc r set2 gnd gnd amp_in v cc gnd gnd gnd gnd out gnd gnd out_a gnd gnd v cc gnd gnd in_a gnd c5* 22pf c4 1000pf c12 open +5v c6 1000pf c13 0.1 f +5v c11 open c2 1000pf +5v c1 22pf c7 22pf c17 0.75pf r1 1.2k ? r2 2k ? c8 1000pf c14 0.1 f +5v c9 1000pf c15 0.1 f r3 0 ? +5v tp1 tp2 gnd c10 22pf c16 open r4 0 ? j3 vcntl j4 j2 c3* 22pf j1 rf_in c3* 22pf *see the modifying the ev kit section for connection configurations. j5 c5* 22pf c5* 22pf rf output 0.06in long fr4 50 ? transmission line figure 1. MAX2057 ev kit schematic
evaluates: MAX2057 MAX2057 evaluation kit _______________________________________________________________________________________ 5 figure 2. MAX2057 ev kit pc board layout?op silkscreen 1.0" figure 3. MAX2057 ev kit pc board layout?op soldermask 1.0" figure 4. MAX2057 ev kit pc board layout?op layer metal 1.0" figure 5. MAX2057 ev kit pc board layout?nner layer 2 (gnd) 1.0"
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. 6 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2005 maxim integrated products printed usa is a registered trademark of maxim integrated products, inc. evaluates: MAX2057 MAX2057 evaluation kit figure 6. MAX2057 ev kit pc board layout?nner layer 3 (routing) 1.0" figure 7. MAX2057 ev kit pc board layout?ottom layer metal 1.0" figure 8. MAX2057 ev kit pc board layout?ottom soldermask 1.0" figure 9. MAX2057 ev kit pc board layout?ottom silkscreen 1.0"
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