general description the max44205 evaluation kit (ev kit) provides a proven design to evaluate the max44205, low-noise, low- distortion fully differential operational amplifier (op amp), suitable for driving high-resolution sar adcs such as the max11905 family of devices. the ev kit pcb comes installed with a max44205atc+ in a 12-pin, 3mm x 3mm tqfn package with an exposed pad. benefts and features fully differential amplifier with 130dbc thd +2.7v to +13.2v supply voltage range output-voltage clamps to prevent overranging adc adjustable output common-mode voltage evaluate 20-bit sar adc + max44205 amplifier (refer to the max11905 ev kit) proven pcb layout fully assembled and tested ordering information appears at end of data sheet. 19-7058; rev 0; 9/14 quick start required equipment max44205 ev kit 5v, 100ma dual dc power supply low-distortion differential-output signal genera - tor (i.e., audio precision 2700, stanford research ds360) 2-channel oscilloscope two sma cables of equal length procedure the ev kit is fully assembled and tested. follow the steps below to verify the board operation: 1) verify that all shunts are in their default positions, as shown in table 1. 2) connect the 5v supply to the vs+, vs-, and gnd test points, respectively. 3) use the sma cables and connect the 10khz, 6.6vp-p sine, differential input from the signal generator to the inp and inm smas on the ev kit. 4) turn on the power supplies. 5) use the oscilloscope and monitor the differential output at jumper ju6. evaluates: max44205 max44205 evaluation kit
maxim integrated 2 detailed description of hardware the max44205 ev kit provides a proven design to evaluate the max44205, low-noise, low-distortion, fully differential op amp, suitable for driving high- resolution sar adcs such as the max11905 family of devices. features of the ev kit include jumpers for shdn control, vclph/vclpl voltage-clamping options, and input for output common-mode voltage (vocm). the ev kit is meant to work using dual supplies where the voltage between vs+ and vs- is +2.7v to +13.2v. shutdown mode ( shdn ) jumper ju1 controls the shutdown mode of the device. the device is in normal operation when the shunt is installed in the 1-2 position on jumper ju1. to place the device in shutdown mode, install a shunt in the 2-3 position on ju1. if the shunt on ju1 is removed, the device is pulled internally to vs+. this option also allows a pulse to be sent through the shdn sma. clamping voltage (vclph and vclpl) jumpers ju2 and ju3 allow the options to connect to the vs+ and vs- supply rails or external supplies (table 1). when the device is driving an adc, connect vclph to the reference voltage of the adc and vclpl to the minimum input voltage (or ground). output common-mode voltage (vocm) jumper ju4 sets the output common-mode voltage to 0v. if the shunt is removed, apply the desired output common-mode voltage from (vs-) + 1.2v to (vs+) - 1.2v at the vocm test point. adjusting the gain adjust the gain by replacing r1Cr4 on the ev kit with appropriate resistors. the gain (a v ) is as follows: v r3 r4 a r1 r2 = = when selecting resistors, use 0.1% tolerance and 10ppm parts when possible. input termination resistors the ev kit has 49.9? termination resistors populated at the r7 and r8 pads at the in+ and in- inputs. these resistors should be removed or replaced appropriately to match the impedance of the signal source. input filter for adc replace r5, r6, and populate c12 appropriately when driving a high-resolution adc like the max11905. additional capacitance can be installed at the c17 and c18 pads. refer to driving a fully differential adc section in the max44205 ic data sheet. component list refer to file evkit_build_bom_max44205_evkit_a.csv attached to this pdf for component information. table 1. jumper functions (ju1Cju5) * default position. note: jumper ju6 has no shunt; it is used for probing only. jumper shunt position description ju1 1-2* normal operation 2-3 shdn . max44205 is in shutdown mode. ju2 1-2* vclph is connected to vs+. 2-3 external vclph. apply a voltage no greater than (vs+) + 0.42v at the ext_vclph test point. ju3 1-2* vclpl is connected to vs-. 2-3 external vclpl. apply a voltage no greater than (vs-) + 0.54v at the ext_vclpl test point. ju4 not installed user-supplied vocm. apply (vs-) + 1.2v to (vs+) - 1.2v at the vocm test point. installed* vocm is connected to gnd. ju5 not installed* disconnects vs- from gnd. installed connects vs- to gnd. www.maximintegrated.com evaluates: max44205 max44205 evaluation kit
maxim integrated 3 figure 1. max44205 ev kit schematic qp r gcm o mp d ubkok nodm o mp d qpq ur j q s r t p q s r t unbl p q s r t hm l tr sq qv s x mx pp bs t r s q nt s l t r s q bpv f mc p s x mx nodm bps o mp t e o mp t e bpu itt o l ws s qot s b j qpo nodm itu ubkog p ooj nodm p tp o mp d o mp d pj qt nodm qu qp p nodm o f mc f mc ur j ur j ur j r gcm bpw p ot e br o mp t e p ot e p bq dws ~ubkok p ot e bw ubkok r bu o mp t e itr q p ur l dws ~ubkog bv p ot e nt s o p p ubkog bt r o mp t e q itq p ur j bpq bpp nodm qr o mp d pj r gcm r q u s q r v w it p t q p pj x pq p pr po o mp t e bx s mx x j qx ur l ur l ur l bpt q p bp o mp t e p ot e bpr p ot e qs pj o mp d bpo qq qw o mp d p f mc unbl q its h mo do h ml m mb m h mj r gcm ur l ubkok nt s l f mc nt s j ubkog ur j unbl www.maximintegrated.com evaluates: max44205 max44205 evaluation kit
maxim integrated 4 figure 2. max44205 ev kit component placement guide component side figure 3. max44205 ev kit pcb layoutcomponent side figure 4. max44205 ev kit pcb layoutsolder side figure 5. max44205 ev kit component placement guide solder side 1? 1? 1? 1? www.maximintegrated.com evaluates: max44205 max44205 evaluation kit
maxim integrated 5 part type MAX44205EVKIT# ev kit ordering information www.maximintegrated.com evaluates: max44205 max44205 evaluation kit
? 2014 maxim integrated products, inc. 6 revision number revision date description pages changed 0 9/14 initial release revision history maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and specifcations without notice at any time. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. evaluates: max44205 max44205 evaluation kit for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com.
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