19-0409; rev 1; 3/07 m ax 3 6 5 4 eva lua t ion k it ________________ ge ne ra l de sc ript ion ______________________ ____________________ maxim integrated products 1 for pricing, delivery, and ordering inform ation, please contact maxim/dallas direct! at 1-888-629-4642, or visi t maxims website at www.maxim-ic.com. eva lua t e s: m ax 3 6 5 4 the max3654 evaluation kit (ev kit) is a factory- assembled printed circuit board (pcb) that provides two circuit versionsoptical input and electrical input. the optical circuit includes the photodiode bias circuitry, an op amp for feed-forward agc operation, and a balun for single-ended 75 output. through-hole pads are provided to attach a triplexer analog photodiode. it is important to select a photodiode with capacitance and inductance in the anode and cathode connections as symmetric as possible for optimum linearity. the electrical circuit is normally configured with a 50 input for use with conventional test and measurement equipment and a 75 output. the 75 output can be connected to 50 test and measurement equipment using a minimum loss pad. if desired, the max3654 input can also provide a 75 input by replacing r12 and r13 with 25 resistors. _________________________ fe a t ure s ? fully assembled and tested ? optical and electrical inputs ? automatic gain control _______________orde ring i nform a t ion part temp range ic-package MAX3654EVKIT -40c to +85c 16 qfn __________________________________________________ eva lua t ion com pone nt list designation qty description c1, c2, c4, c5, c19Cc22 8 0.001 f 10% ceramic capacitors (0402) c3, c7, c8, c9, c12, c16, c17, c23, c24, c27, c29 11 0.1 f 5% ceramic capacitors (0603) c6, c10, c11, c25, c26 5 1 f 10v, 10% min ceramic capacitors c13, c14, c28 3 33 f 10v, 20% min tantalum capacitors r6, r18 2 1.62k 1% resistors (0402) r2 1 10 1% resistor (0402) r3, r4, r5, r16, r17 6 100k 1% resistors (0402) r1, r21 2 1k 1% resistors (0402) r7, r19 2 2.43k 1% resistors (0402) r9, r15 2 20k 1% resistors (0402) r12, r13 2 12.1 1% resistors (0402) r8, r20 2 6.04k 1% resistors (0402) r22 1 open (0402) designation qty description j2, j4 2 bnc 75 , edge mount trompeter ucbje20-1 j3 1 sma connector, tab contact, johnson, 142-0701-851 tp1Ctp13 13 test points ju1Cju3, ju5, ju6 5 2-pin headers, 0.1in centers l1, l5 2 bead, murata blm15hd182sn1 (0402) l2, l6 2 10 h inductor, tdk mlf1608e100k (0603) u1, u3 2 max3654ete+ u2, u4 2 max4240euk u5 0 photodiode not supplied u6 1 balun pulse engineering cx2039 u7, u8 2 balun pulse engineering cx2038 downloaded from: http:///
m ax 3 6 5 4 eva lua t ion k it 2 _________________________________________________________________________________________ _____________com pone nt supplie rs supplier phone eva lua t e s: m ax 3 6 5 4 website avx 803-448-9411 www.avxcorp.com pulse engineering 858-674-8100 www.pulseeng.com murata 770-436-1300 www.murata.com note: please indicate that you are using the max3654 when contacting these component suppliers. ________________________quic k st a rt opt ic a l eva lua t ion 1) attach triplexer photodiode to in+ and in- of the max3654. the cathode normally connects to in+. the photodiode case should be grounded to the most convenient ground via. make certain that the anode and cathode leads are symmetric in length and orientation, lead lengths should normally be about 5mm. 2) set ju2 to r4 to manually adjust the gain with an input from 0 to 1.4v on tp3. 3) leave ju3 open for minimum hysteresis. 4) set ju1 to r8 to enable the output signal. 5) connect the signal output at j2 to a 75 spectrum-analyser input. a minimum loss pad may also be used to connect j2 to 50 test equipment. 6) connect a +5v supply to the vcc terminal, tp1 and ground to the gnd terminal, tp2. 7) connect the photodiode bias supply to tp13. typically use +12v bias supply, or as required by the photodiode. ele c t ric a l eva lua t ion 1) connect a 50 signal source to in at j3. set the input signal level to p in = -18dbm, so that the voltage on 50 produces the maximum input level of 1.6ma p-p . 2) connect the rf output at j4 to a 75 ? spectrum analyser input. a minimum loss pad may also be used to connect j4 to 50 test equipment. 3) leave ju6 open for minimum hysteresis. 4) set ju5 to r20 to enable output. 5) connect a +5v supply to the vcc terminal, tp7 and ground to the gnd terminal, tp8. 6) apply 1.4v to tp12 to set the max3654 gain to minimum, 43.5db ? . a voltage from 0.175v to 1.4v at tp12 adjusts the gain from 62db ? to 43.5db ? i nput a nd out put signa l le ve ls when used in the electrical input configuration shown in figure 2, the max3654 is intended to operate with ac input signal current from 175 a p-p to 1.6ma p-p . the corresponding electrical input is -37dbm (0 < vagc < 0.175v) to -18dbm (vagc = 1.4v), on 50 . the max3654 ev kit can also be configured to provide 75 input impedance by replacing r12 and r13 with 25 resistors. when used in the optical input configuration shown in figure 2, ju2 may be connected to r3 to configure the max3654 for agc operation based on the average optical power level. in this case, the max3654 transimpedance is controlled by the average optical power level, as measured by the voltage across r21. the values of r1, r21 and r22 shown in figure 1 will provide an output level of 15dbmv/ch ( + 1db) for optical input signals ranging from -6dbm to +2dbm, (omi = 3.5%, n = 129) using a typical triplexer photodiode. the total output signal level in this case is 15dbmv/ch + 10 log(129 channels) = 36dbmv, which is the maximum operating level at which the specified linearity will be achieved. operating at higher outputs may reduce max3654 performance. operating conditions (omi, number of channels, responsivity, etc) change the vagc setting required for a given output voltage. ev kit agc circuit gain can be increased by adding a voltage-divider, r22, to the op amp. to reduce gain the values of r1 and r21 should both be increased. remember to keep the total output at 36dbmv or less to maintain the desired max3654 performance. phot odiode le a d configura t ion photodiode lead parasitic im pedances can significantly effect performance of the max3654. it is especially important that the anode an d cathode connections are electrically symmetric. refer to figure 1 in the max3654 data sheet. note that the ev kit layout is designed to minimize capacitance to ground in the input signal path. downloaded from: http:///
m ax 3 6 5 4 eva lua t ion k it _____________________________________adjust m e nt s a n d cont rol de sc ript ions component electrical optical name eva lua t e s: m ax 3 6 5 4 function ju5 ju1 mute mute. ttl high enables output. low mutes output. na ju2 vagc gain control. set ju2 to r4 fo r manual gain control. set ju2 to r3 to allow feedforward agc operation. the electrical circuit board is always set for manual gain control. ju6 ju3 hysteresis hysteresis. leave open for (minimum) 0.13db hysteresis between gain switch points. connect 20k to ground for 0.3db and short to gnd for (maximum) 0.65db hysteresis. max3654 vcc in+ in- vcc vcc out+ out- vcc ep* vagcmute hyst gnd gnd test2 gnd test1 + - r1 1k r21 1k r3 100k c1c2 0.001 f 0.001 f c6 1 f r22 open c7 0.1 f c29 0.1 f r5 100k c11 1 f r4 100k c10 1 f l5 l6 blm15hd182sn1 bead bead l1 l2 v pd max4240 v cc v cc v cc v cc v cc v cc c12 0.1 f u2 u1 12 3 4 5678 ep 9 10 11 12 13 14 15 16 r9 20k r8 r7 r6 6.04k 2.43k 1.62k c9 0.1 f c5 0.001 f c4 0.001 f c8 0.1 f j2 u8 ju3 ju1 33 f c13 tp1tp2 v cc gnd v cc tp6 gain ju2 tp3 *ep - exposed pad, solder to gnd cx2038 tp13 v pd c14 33 f v pd blm15hd182sn1 vagc mute hyst tp5 tp4 10 h r2 10 0.1 f c3 10 h u5 figure 1. max3654 optical ev kit schematic ____________________ __________________ _________________ 3 downloaded from: http:///
m ax 3 6 5 4 eva lua t ion k it 4 ________________________________________________________________________________________ max3654 vcc in+ in- vcc vcc out+ out- vcc ep* vagc mute hyst gnd gnd test2 gnd test1 + - c20 c19 0.001 f 0.001 f c16 0.1 f c17 0.1 f r17 100k c26 1 f r16 100k c25 1 f max4240 v cc v cc v cc v cc v cc v cc c27 0.1 f u4 u3 12 3 4 5678 ep 9 10 11 12 13 14 15 16 r15 20k r20 r19 r18 6.04k 2.43k 1.62k c24 0.1 f c22 0.001 f c21 0.001 f c23 0.1 f j4 u7 ju6 ju5 33 f c28 tp7 tp11 v cc gnd v cc tp12 gain u6 tp9 j3 r12 r13 12 12 cx2039 cx2038 *ep - exposed pad, solder to gnd hyst mute tp8 tp10 eva lua t e s: m ax 3 6 5 4 figure 2. max3654 electrical ev kit schematic downloaded from: http:///
m ax 3 6 5 4 eva lua t ion k it 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 circui try and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 940 86 408-737-7600___ __________ ______ 5 eva lua t e s: m ax 3 6 5 4 figure 3. max3654 ev kit pc component placement guide component side figure 4. max3654 ev kit pc board layoutcomponent side figure 5. max3654 ev kit pc board layoutground plane figure 6. max3654 ev kit pc board layoutpower plane figure 7. max3654 ev kit pc board layoutsolder side ? 2007 maxim integrated products is a registered trademark of maxim integrated products downloaded from: http:///
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