_________________________________________________________________ maxim integrated products 1 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim?s website at www.maxim-ic.com. max3657 evaluation kit ________________ general description the max3657 evaluation kit is a fully assembled chip-on- board electrical demonstration kit that provides easy evaluation of the max3657 155mbps +3.3v trans- impedance amplifier. note that the max3657 evaluation kit provides an electrical interface to the ic that is similar, but not exactly the same as a photodiode. ____________________________ features ? easy +3.3v electrical evaluation of the max3657 ? fully assembled and tested ? ev kit designed for 50 ? ? ? ? interfaces ______________ ordering information part temp. range ic package max3657 evkit -40c to +85c dice ______________component suppliers supplier phone fax avx 843-444-2863 843-626-3123 coilcraft 847-639-6400 847-639-1469 digi-key 218-681-6674 218-681-3380 ef johnson 402-474-4800 402-474-4858 murata 415-964-6321 415-964-8165 note: please indicate that you are using the max3657 when ordering from these suppliers. ____________________ component list designation qty description c2 c23 2 0.01 f 5% ceramic capacitor (0201) - do not install c3 1 10 f 10% tantalum capacitor do not install c4 1 0.9pf .075pf ceramic capacitor (0402) c5 c100 2 0.01 f 10% ceramic capacitor (0402) c6, c7, c24, c27 4 1 f 5% ceramic capacitor (0402) do not install c8, c9, c13, c14, c96, c98, c118, c119 8 1 f 5% ceramic capacitor (0402) c17, c99 2 10 f 10% tantalum capacitor c97 1 0.4pf 0.05pf ceramic capacitor (0402) j3 j4 j5, j22 j26 j27 6 sma connectors (edge-mount, round) j19, j23, j24, j25 4 sma connectors (edge-mount, round) do not install ju3, ju4, ju5, ju6 4 2-pin headers (0.1in centers) l1 1 56nh inductors (0805) coilcraft cs-560xkbc do not install l2 l30 2 56nh inductors (0805) coilcraft cs-560xkbc designation qty description r2, r98 2 49.9 ? 1% resistor (0402) r3, r4 r120, r121 4 100 ? 1% resistor (0402) r5 r100 2 10k ? 1% resistor (0402) r6 1 1k ? 1% resistor (0402) r7, r38 2 499 ? 1% resistor (0402) r28-r29 r33- r34 4 100 ? 1% resistor (0402) do not install r31 1 1k ? 1% resistor (0402) do not install r99 r102 r103 3 4.99k ? 1% resistor (0402) tp2, tp4, tp5, tp6 tp8, tp9, tp10 tp13- tp14, tp19 10 testpoint digi-key 5000k- nd tp1, tp18, tp11, tp12 4 testpoint digi-key 5000k- nd do not install u1 1 max3657 etc 12 qfn u2 1 max3657 die u3 1 user supplied 4 pin to can u4 1 user supplied 5 pin to can 19-2898; rev 1, 9/03
max3657 evaluation kit 2 ________________________________________________________________________________________ evaluate: max3657 _________________________ quick start test equipment required test equipment required test equipment required test equipment required +3.3v power supply with 100ma current capability signal-source, 155mbps minimum capability oscilloscope with at least 100mhz performance procedure procedure procedure procedure this procedure will set up the 12 pin qfn section of the evaluation board for 155mbps operation. 1) connect a signal source to j26 (in). set the signal amplitude to 250mv p-p (corresponding to 250 a p-p current into the tia). set the data rate to 155mbps. 2) apply 150 a to the dc_in test point (tp10) using a constant current source to emulate the dc component of the input signal. a voltage source connected from tp10 to gnd may be used if a constant current source is not available. 3) connect out+ (j22) and out- (j27) to the 50 inputs of a high-speed oscilloscope. 4) remove the shunt from ju6 to enable the dc cancellation loop. 5) install the shunt on ju5.to enable the average current monitor. 6) connect a 3.3v supply to the supply terminal (tp 13) and to the gnd terminal. 7) the differential signal at the oscilloscope should be approximately 150mv p-p . _______________ detailed description the max3657 accepts a dc-coupled input from a high- speed photodiode, for optical modulation amplitudes ranging from -38dbm to 0dbm. the max3657 evaluation board facilitates characterization of the max3657 tia with or without a photodiode. the max3657 comes from the factory with the die attached and 12 pin qfn sections completely assembled. the user must assemble the to header sections, if used. die attached section die attached section die attached section die attached section the die-attached section provides a simple circuit for emulating a photodiode current input. the connector at in (j1) is terminated with 50 to ground. signal voltage applied to the evaluation kit's input is ac coupled to a resistance in series with the max3657's input, creating an input signal current. photodiode dc current can be emulated by injecting dc current into the dc_in_ pin. 12 pin qfn section 12 pin qfn section 12 pin qfn section 12 pin qfn section the 12 pin qfn section provides photodiode emulation using similar circuitry as the die-bonded section. an optional to assembled photodiode interface is also provided. to use a to mounted photo diode, remove r38, r7, and c4. figure 2 shows a typical mounting scheme for a photo diode in a to header. 4 and 5 pin to header layout 4 and 5 pin to header layout 4 and 5 pin to header layout 4 and 5 pin to header layout the to header assembly layout provides a user- assembled interface for evaluation of 4 and 5 pin to headers. (see the max3657 datasheet for a suggested to header layout.) test equipment interface test equipment interface test equipment interface test equipment interface the max3657 outputs are back terminated with 100 ohms. to facilitate interface with 50 equipment, the max3657 ev kit places external 100 termination resistors in parallel with each output so that the ev kit will match a 50 environment. note that the output load has a direct effect on the overall gain and output signal swing. because of the external 100 resistors, the overall gain is reduced by 50%. if matching a 50 environment is not critical, higher gain can be achieved by increasing the load resistance. photodiode emulation photodiode emulation photodiode emulation photodiode emulation use the following procedure to emulate the high-speed current signal generated by a photodiode: select the desired optical power (pave in dbm) and extinction ratio (re). calculate the average current (iave in amps) as follows: 1000 10 i ) 10 / p ( avg ave where is photodiode responsivity in a/w calculate the ac signal current (i input in amps p-p ) as follows, and adjust the signal generator to obtain it: ) 1 re ( ) 1 re ( i 2 i ave input for example, to emulate a signal with an average power of -25dbm and an extinction ratio of 8. -25dbm optical power will produce 2.7 a of average input current (assume a photodiode responsivity of 0.85a/w). install a current meter between an external dc source and the dc_in test point. adjust the source to provide 2.7 a. the signal amplitude is 2i ave (r e -1)/(r e +1) = 4.2 a. to generate this current through the two 4.99k series input resistors and the 800 internal resistance, set the signal source to produce an output level of 45mv p-p . noise measurements noise measurements noise measurements noise measurements remove the input resistors and shunt capacitor before attempting noise measurements. be very careful when working around the exposed bond wires of the die bonded section. with the input resistors and shunt capacitor removed, the total capacitance at the in pin is approximately 0.25pf for the die-attached section and about 0.5pf for the qfn section.
max3657 evaluation kit _________________________________________________________________________________________ 3 evaluate: max3657 max3657egg u1 1 nc 6 filt 5 in 4 mon 3 gndz 2 gnd 11 nc 10 out+ 9 nc 8 vcc 7 vccz 12 out- 3.3v tp13 l2 56nh c17 10 f j10 j26 in1 r2 49.9 c9 1 f r5 10k c8 1 f r7 499 r38 499 tp10 dc_in1 c4 0.9pf ju6 tp9 mon1 ju5 r6 1k c13 1 f c14 1 f r3 100 r4 100 j27 out1- j22 out1+ c5 .01 f vcc1 vcc1 tp14 detail a max3657e/d u2 6 filt 5 in 4 mon 3 gndz 2 gnd 10 out+ 9 vcc 8 vccz 7 nc 1 out- 3.3v tp6 gnd tp2 l30 56nh c99 10 f vcc2 tp4 j5 in2 r98 49.9 c96 1 f r103 4.99k r99 4.99k c97 0.4pf r100 10k c98 1 f tp5 dc_in2 tp8 mon2 ju3 r102 4.99k ju4 c100 .01 f vcc2 c118 1 f c119 1 f r120 100 r121 100 j4 out2- j3 out2+ detail a: optional interface for photodiode to header gnd tp19 figure 1. max3657 ev kit schematic diagram - qfn and die-attach sections
max3657 evaluation kit 4 ________________________________________________________________________________________ evaluate: max3657 t0-46 can photodiode 6 filt 5 in detail a pd max3657egg (u1) 4 mon figure 2. photodiode interface (qfn section). 3.3v tp18 gnd tp1 l1 56nh c3 10 f vcc3 c27 1 f c24 1 f r29 100 r28 100 j23 out4- j24 out4+ c15 1 f j16 tp11 vcc3 c23 .01 f r31 1k tp12 mon u4 out+ out- mon vcc gnd c6 1 f c7 1 f r34 100 r33 100 j19 out3- j25 out3+ vcc3 c2 .01 f u3 out+ out- gnd vcc alternate ground point figure 3. max3657 ev kit schematic diagram - optional to-header interface (assembly required).
max3657 evaluation kit _________________________________________________________________________________________ 5 evaluate: max3657 figure 4. max3657 ev kit component placement guide - component side figure 5. max3657ev kit pc board layout - solder side
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
2003 maxim integrated products printed usa is a registered trademark of maxim integrated products. figure 6. max3657ev kit pc board layout - ground plane figure 7. max3657ev kit pc board layout - power plane
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