evaluation board user guide ug - 190 one technology way ? p. o . box 9106 ? norwood, ma 02062 - 9106, u.s.a. ? tel: 781.329.4700 ? fax: 781.461.3113 ? www.analog.com differential amplifier evaluation board for single 8 - lead lfcsp packages please see the last page for an important warning and legal terms and conditions . rev. a | page 1 of 8 features flexible board layout accommodates the ad8137 and ad8139 accommodates various circuit configurations enables quick breadboarding/prototyping edge - mounted circu it configuration easy c onnection to test equipment and other circuits rohs compliant general description the analog devices , inc., diffe rential driver evaluation board makes it easy for designers to obtain quick performance results for their particul ar differential driver application circuits. the board layout is very flexible and allows for many circuit configur - a tions, including traditional four - resistor circuits, circuits with two different feedback loops, circuits with input and output transformer s, filters, and many others. most resistors and capacitors use 1206 packages. the board accommodates the ad8137 and ad8139 . t he data sheets for these devices should be consulted in conjunction with this evaluation board user guide . notes 1. the evaluation board part number on your board may appear different than what is shown on the board pictured here. 09336-002 figure 1 . board photograph component side 09336-003 figure 2. board photograph circuit side
UG-190 evaluation board user guide rev. a | page 2 of 8 table of contents features .............................................................................................. 1 general description ......................................................................... 1 revision history ............................................................................... 2 evaluation board hardware ............................................................ 3 power supplies .............................................................................. 3 feedback networks and input/output terminations ............. 3 v ocm input ..................................................................................... 3 measuring output common - mode voltage ............................ 3 input/output transformers .........................................................3 sma input/output connectors ..................................................4 other components .......................................................................4 evaluation board schematic and layout ........................................5 ordering information .......................................................................6 bill of materials ..............................................................................6 related links ..................................................................................6 revision history 10 /12 rev. 0 to rev. a changes to figure 1 and figure 2 ................................................... 1 changes to figure 4 to figure 7 ...................................................... 5 9/10 revision 0: initial version
evaluation board user guide UG-190 rev. a | page 3 of 8 evaluation board har dware power supplies power is a pplied to the board through p1, a molex? 3- pin header , part number 22- 11- 2032 (see figure 1 and figure 3 ). pin 1 (square footprint) is for the positive supply, pin 3 is for the negative supply, and pin 2 i s connected to the ground plane of the board. alternatively, looped test points can be used. tp2 connects to the positive supply, tp3 connects to the negative supply, and tp 5 th r ough tp 10 connect to the ground plane. the board accommodates sing le or dual supplies. for single - supply operation, connect the negative supply to the ground plane. it is very important that the power supply pins of the device under test (dut) have broadband decoupling circuitry. the board layout facilitates this with fo otprints for two 1206 ceramic capacitors on each supply. at frequencies beyond the resonant frequency of the first capacitor and its associated internal and external inductance, the second capacitor provides the required low impedance return current path. for optimum performance, place the smaller of the two capacitances closest to the dut, in the c8 and c11 positions (see figure 3 ). c10 and c12 can also be used for additional power supply bypassing. c13 provides the user with the o ption of adding differential decoupling between the supplies . bulk decoupling is provided by c1 and c2; 10 f tantalum capacitors are recommended. feedback networks and input/output terminations r19 and r17 compose the upper resistive feedback loop (see figure 3 ), and r20 and r18 compose the lower feedback loop . c3 and c4 are included across the feedback resistors to provide frequency - dependent feedback , typically used to introduce a real - axis pole in the closed - loop frequency resp onse . to minimize summing node capacitances, the ground plane under and around pin 1 and pin 8 of the dut and the copper that connects to them ha ve been removed . r6 and r7 are included as input termination resistors for applica tions that have single - ended inputs. having a place for a shunt resistor on each input makes it simple to match the two feed back factors. a common example of how this is used is when the input signal origina tes from an unbalanced 50 ? source. in this case, the single - ended termination resistance is 50 ?, and the thevenin equivalent resistance seen looking back to the source is 25 ?. for the traditional four - resistor configuration , where r19 = r20 and r17 = r1 8, the feedback networks are matched by making the shunt resistor on the input leg opposite the termination resistor equal to 25 ?. r5 is provided for differ ential termination . r15 and r16 series termination resistors are provided on each of the outputs f or impedance matching, analog - to -digital converter (adc) driving, and other system requirements. v ocm input the v ocm input can be set to a dc level by adjusting the r1 p otentiometer that spans the power supplies. for the dc case, c9 is provided at the wipe r for decoupling. an external voltage can be applied to v ocm via tp4 (referenced to the ground plane of the board). in adc driving applications, it is convenient to apply the adc dc reference voltage output directly to tp4. it is also possible to drive the v ocm input from an external ac source. in this case, omit c9 or reduce it to a value that allows the desired signal to be passed. for high frequency signals on v ocm , connect the center conductor of a coaxial cable to tp4 and ground its shield at tp10. r21 is provided for the high common - mode output impedance application illustrated in the ad8132 data sheet. measuring output com mon- mode voltage the internal common - mode feedback loop us ed in the differen - tial drivers forces the output common - mode voltage to be equal to the voltage applied to the v ocm input, thereby providing excellent output balance. r11 and r12 form a voltage divider across the differential output, and the voltage at th e divider tap is equal to the output common - mode voltage, provided that r11 and r12 are exactly matched in value. if r11 and r12 are used to evaluate the output common - mode voltage, they should be measured and matched to better than 300 ppm to obtain resul ts commensurate with the dut output balance error performance of ?70 db. test point pr1 accepts coaxial - type oscilloscope test points, such as the berg electronics 33jr135 - 1. input/output transfo rmers the board has the added flexibility of allowing the use r to incorpo - rate transformers on its input and output. this capability can be especially useful when connecting to single - ended test equipment. because both input and output transformers have dual, nested footprints, the user can select from a wide array of transformers available from companies such as mini - circuits? and coilcraft?. the layout provides footprints for connecting resistors to ground on the primary and secondary transformer center taps, offering the user a number of options with regard to the common - mode properties of the evaluation circuit. jp1, jp2, jp3, and jp4 are jumpers on the back side of the board that provide direct shunts across their associated transformers. when not using a transformer, bypassing the transformer is a simple matter of shorting the appropriate jumpers. when using a transformer, it is a good idea to verify that the associated jumpers are open.
UG-190 evaluation board user guide rev. a | page 4 of 8 sma input/output con nectors the inputs and outputs have edge - mounted s u bminiature a (sma) connectors for straightforward connection to coaxial cables . the recom mended connector type is johnson components? , part number 142- 0701 - 801 or equivalent. other components the components described in this user guide pertain mostly to traditional amplifier topologies. footprints are provided for a number o f other components on the board to allow the user to be more creative than the traditional designs . a component labeled as a capacitor need not be a capacitor provided that it fits the users application circuit and the footprint on the board. in applicati on circuits where footprints for desired components are not available on the board, the user is encouraged to find ways to include them. for example, if an additional shunt element is required, the user can scrape some solder mask away from the ground plan e and trace (if necessary) to make a place for the additional part. furthermore, 1206 elements can be stacked on top of each other to implement a parallel circuit. an example of this includes stacking capacitors across r17 and r18 to realize a zero in the closed - loop transfer function. this is one way to insert pre - emphasis in a line - driver application.
evaluation board user guide UG-190 rev. a | page 5 of 8 evaluation board schematic and layout j3 j4 r4 r2 r3 jp1 p1 1 2 v+ v? c2 + + c1 r6 r7 jp2 t1, t3 3 r5 r18 r17 r1 v? v+ c9 tp4 2 1 8 v ocm dut c10 c11 tp3 v? c6 c4 r20 6 4 5 3 tp1 r19 c3 c5 j1 j2 r10 r9 jp4 r8 jp3 t2, t4 c13 r15 r16 v+ c12 c8 tp2 r12 r11 pr1 r21 r13 r14 tp10 tp5 tp6 tp7 tp8 tp9 7 r23 r24 r22 j5 v? 09336-001 figure 3 . evaluation board schematic 09336-004 figure 4. assembly d rawing , component side 09336-005 figure 5. assembly drawing, c ircuit side ( lfcsp ) 09336-006 figure 6. metallization , component side 09336-007 figure 7. metallization , circuit side
UG-190 evaluation board user guide rev. a | page 6 of 8 ordering information bill of materials table 1 . qty reference designator description package 2 c1, c2 10 f capacitor 3216 10 c3 to c6, c8 to c13 capacitor, user - defined value c1206 5 j1 to j5 sma connector smasmt 4 jp1 to jp4 jumper jprsld02 1 p1 3-p in header, molex part 22 -11- 2032 pwr_conn_6 -9-2 1 pr1 sma connector smacon 1 r1 1 k? potentiometer 3299w 23 r2 to r24 resistor, user defined value r1206 2 t1, t2 transformer etc1 -6 2 t3, t4 transformer kk81 1 tp1 test point tp 9 tp2 to tp10 test point tp104 1 u1 device under test 8- lead lfcsp 1 pc board related links resour ce description ad813 7 product p age, ad813 7 low cost, l ow p ower d ifferential adc d river ad8139 product p age, ad8139 low noise, r ail - to -r ail, d ifferential adc d river
evaluation board user guide UG-190 rev. a | page 7 of 8 notes
UG-190 evaluation board user guide rev. a | page 8 of 8 notes esd caution esd (electrostatic discharge) sensitive device . charged devices and circuit boards can discharge without detection. although this product features patented or proprietary protection circuitry, damage may occur on devices subjected t o high energy esd. therefore, proper esd precautions should be taken to avoid performance degradation or loss of functionalit y. legal terms and conditions by using the evaluation board discussed herein (together with any tools, components documentation or support materials, the evaluation board), you are agreeing to be bound by the terms and conditions set forth below (agreement) unless you have purchased the evaluation board, in which case the analog devices standard terms and conditions of sale shall govern. do not use the evaluation board until you have read and agreed to the agreement. your use of the evaluation board shall signify your acceptance of the agreement. this agreement is made by and between you (customer) and analog devices, inc. (a di), with its principal place of business at one technology way, norwood, ma 02062, usa. subject to the terms and conditions of the agreement, adi hereby grants to customer a free, limited, personal, temporary, non - exclusive, non - sublicensable, non - transf erable license to use the evaluation board for evaluation purposes only. customer understands and agrees that the evaluation board is provided for the sole and exclusive purpose referenced above, and agrees not to use the evaluation board for any other pur pose. furthermore, the license granted is expressly made subject to the following additional limitations: customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the evaluation bo ard; and (ii) permit any third party t o access the evaluation board. as used herein, the term third party includes any entity other than adi, customer, their employees, affiliates and in - house consultants. the evaluation board is not sold to customer; all rights not expressly granted herein, including ownership of the evaluation board, are reserved by adi. confidentiality. this agreement and the evaluation board shall all be considered the confidential and proprietary information of adi. customer may not disclose or transfer any portion of th e evaluation board to any other party for any reason. upon discontinuation of use of the evaluation board or termination of t his agreement, customer agrees to promptly return the evaluation board to adi. additional restrictions. customer may not disassembl e, decompile or reverse engineer chips on the evaluation board. customer shall inform adi of any occurred damages or any modifications or alterations it makes to the evaluation board, including but not limited to soldering or any other activity that affects the material content of the evaluation board. modifications to the evaluation board must comply with applicable law, including but not limited to the rohs directive. termi nation. adi may terminate this agreement at any time upon giving written notice to customer. customer agrees to return to adi the evaluation board at that time. limitation of liability. the evaluation board p rovided hereunder is provided as is and adi makes no warranties or representations of any kind with respect to it. adi specifically disclaims any representations, endorsements, guarantees, or warranties, express or implied, related to the evaluation board including, but not limited to, the implied warranty of merchantability, title, fitness for a particul ar purpose or noninfringemen t of intellectual property rights. in no event will adi and its licensors be liable for any incidental, special, indirect, or consequential dam ages resulting from customers possession or use of the evaluation board, including but not limited to lost profi ts, delay costs, labor costs or loss of goodwill. adis total liability from any and all causes shall be limited to the amount of one hundred us dollars ($100.00). export. customer agrees that it will not directly or indirectly export the evalua tion board to another country, and that it will comply with all applicable united states federal laws and regulations relating to exports. governing law. this agreement shall be governed by and construed in accordance with the substantive laws of the commonwealth of massachusetts (excluding conflict of law rules). any legal action regarding this agreement will be heard in the state or federal courts having jurisdiction in suffolk county, massachusetts, and customer hereby submits to the personal jurisdiction and venue of such courts. the united nations convention on contracts for the international sale of goods shall not apply to this agre ement and is expressly disclaimed. ? 2010 C 2012 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. ug09336 -0- 10 /12(0)
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