afbr-0544z evaluation kit for the AFBR-5972Z fiber optic transceiver application note 5532 evaluation board the afbr-0544z evaluation board gives the system designer a convenient means to evalute the performance of the avago AFBR-5972Z fber optic transceiver module, as well as future compatible products. as shown in figure 1, the evaluation board is mounted with an AFBR-5972Z module, four sma connectors for diferen - tial input/output signals, a 2-pin header for measuring rf diferential signals using a diferential probe, and three 2 mm jacks for the 3.3 v supply voltage and signal detect (sd). this application note describes the evaluation printed circuit board (pcb), the test equipment, and the methods for evaluating optical and electrical characteristics of the the AFBR-5972Z transceiver module. figure 1. evaluation board for the AFBR-5972Z transceiver module application note outline 1. evaluation kit 2. evaluation pcb description 3. electro-optical test confgurations 4. evaluation board schematic and bill of materials (bom) 1. evaluation kit the afbr-0544z evaluation kit includes: (a) evaluation board with AFBR-5972Z module, four sma connectors, 2-pin header and three 2 mm jack connectors and electronic components mounted on bottom side of pcb (b) 1 m simplex pof cable (na = 0.5) - p/no. hfbr-rns001z (c) afbr-4526z duplex connector for AFBR-5972Z (d) 1 m pof, with two afbr-4526z duplex connectors - p/no. hfbr-rsd001z (to demonstrate only the mechanical properties of the duplex connector) not included in the evaluation kit are: (a) 3.3 v dc power supply and power supply cables (b) digitial multimeter (c) mpi 1632c digital data analyzer (pattern generator) (d) sda 600a serial data analyzer (oscilloscope) (e) femto (o/e) converter (f ) diferential probe
2 2. evaluation board description the evaluation board schematic is shown in figure 2. the diferential lvds or lvpecl electrical inputs signal of the transmitter are ac coupled through 100nf capacitors and connected by 50 ? transmission lines to sma connectors. the diferential lvpecl electrical outputs from lvpecl ter - mination of the receiver are ac coupled through 100nf capacitors and connected by 50 ? transmission lines to sma connecters. the signal detect (sd) pin is lvpecl com - patible. the thick line between sma connector and the input/output pins of AFBR-5972Z represents a 50 ? trans - mission in the schematics (figure 2). the top and bottom- sides of the evalution pcb are shown in figure 3(a) and 3(b) respectively. the evaluation board is a two-layer pcb designed for 125 mbit/s. the transceiver diferential lines are placed below the ground plane (top side) to ensure a low inductance signal return path and continuous impedance along the trace. the ground plane under/around the transceiver helps the tranceiver dissipate thermal energy. a 1.57 mm pcb thickness is used so that the AFBR-5972Z mounting clip can be ftted properly. for best transceiver perfor - mance, the decoupling capacitor and ferrite bead should be placed as close as possible to the tranceiver supply voltage, as shown in figure 3(b). table 1 describes the input/output interface.the input/ output interface is shown on the top side of the evalua - tion board. figure 2. schematic of the afbr-0544z evaluation board figure 3(a). top side of the afbr-0544z evaluation board figure 3(b). bottom side of the afbr-0544z evaluation board table 1. input/output description name description signal level td+ diferential transmitter inputs lvds, lvpecl td- rd+ diferential receiver outputs lvpecl rd- sd signal detect dp diferential receiver output signal for diferential probe measurement 3v3 transmitter and receiver power supply 3.3 v gnd transmitter and receiver ground gnd
3 3. electro-optical test confguration the two basic test confgurations for evaluating the afbr- 5972z module are shown in figure 4 (transmitter) and figure 5 (receiver). the transceiver module can be char - acterized for optical/electrical characteristics such as eye diagram, rise and fall time, jitter, and current consump - tion. low loss and matched equal length rf cables should be used to connect the td+/- and rd+/- signals to the test equipment. the current consumption measurement is for the whole transceiver, transmitter and receiver. transmitter measurement confguration figure 4 shows the transmitter measurement confgura - tion. the transmitter characteristics can be tested for light optical power (lop), rise and fall time, and jitter perfor - mance, including the eye diagram measurement. in this confguration, the receiver section is not used; however, it is recommended that rd+ and rd- be terminated with 50 ? matched loads. it is also recommended that a low loss and equal length rf cable can be used to connect td+ and td- to the test equipment. figure 4. transmitter measurement setup confguration figure 5. receiver measurement setup confguration receiver confguration figure 5 shows the receiver measurement confguration. the 1 m pof cable, which is provided with the evalua - tion kit, is used to obtain a transmission link between transmitter and receiver. the gray simplex connector is connected to the transmitter, and the blue simplex connector is connected to the receiver. the receiver char - acteristics can be tested for current consumption, rise and fall time, and jitter performance, including an eye diagram measurement. results the measurements are carried out using the confgura - tion shown in figure 4 and figure 5. the pattern generator is set to a prbs 2 7 -1 pattern and data rate of 125 mbit/s with lvds compatible diferential signals. the transmitter light optical power (lop), measured with an optical power meter (opm) at 650 nm, was -5.57 dbm with a current con - sumption of 78 ma @ 3.3 v supply voltage. figure 6 shows the transmitter eye diagram after the optical-to-electrical converter block. figure 7 shows the receiver eye diagram measured with the diferential probe at dp, as shown in figure 3(a). the current consumption is 79 ma. the sd voltage is 1.63 v with no optical input and 2.33 v with an optical signal.
for product information and a complete list of distributors, please go to our web site: www.avagotech.com avago, avago technologies, and the a logo are trademarks of avago technologies in the united states and other countries. data subject to change. copyright ? 2005-2015 avago technologies. all rights reserved. av02-3144en - may 13, 2015 figure 6. transmitter eye diagram figure 7. receiver eye diagram 4. evaluation board schematic and bill of material (bom) the afbr-0544z evaluation board electrical schematic is shown in figure 2, and the bill of materials (bom) is given in table 2. table 2. afbr-0544z bill of materials component type value footprint comments 3v3 jack, 2 mm red gnd jack, 2 mm black sd jack, 2 mm white r1, r2, r6, r7, r8 smd resistor 130 r0805 not populated r3, r10 smd resistor 82 r0805 not populated r4, r5 smd resistor 150 r0805 r9 smd resistor 220 r0805 r11 smd resistor 10 k ? r0805 c1, c2, c3, c5, c6, c8, c9 smd capacitor 100 nf c0805 c4, c7 smd capacitor 10 f c1206 tantalum jp1 pin header 1x02 l1, l2 smd inductor 1 h l0805 led smd led r0805 green td+, td-, rd+, rd- st-smb farnell, part no. 1608609 AFBR-5972Z module datasheet AFBR-5972Z
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