phy1097 - 03 -rd- 1. 5 datasheet page 1 phy1097-03 2.5 g bps high sensitivity transimpedance amplifier features ? - 29dbm sensitivity ? up to 2.5 g bps (nrz) data rates ? 150 na rms typical input referred noise ? automatic gain control of output over full input range ? flexible bond pad layout and output signal inversion for simple rosa layout ? received signal strength indicator output ? - 40 to + 9 5c operating temperature range applications ? telecom infrastructure oc48 ? gpon optical network unit (onu) ? 2.5gepon r f voltage regulator pda rx+ rx- vcc gnd pdc 1/2 amplifier signal detect & dc restore 50? agc amp 50? agc signal strength indicator rssi data_invert o/p buffer rssi_dir figure 1: outline block diagr am description the phy1097 is a transimpedance amplifier designed for use within small form factor fi bre optic modules targeted at g iga b it capable passive optical network ( gpon ) applications. working from a 3.3v power supply t he phy1097 integrates a low n oise transimpedance amplifier , with a typical differential transimpedance of 25 k ? , an agc and an output stage. the rssi pad can be used to implement a signal strength monitor circuit. th is is designed to sink or source a current equal to the photodiode current for ease of interfacing. s ensitivity of - 29 dbm can be achieved at 2.5 gbps. the phy1097 is available in die form for mounting on a header to create a rosa when com bined with suitable optics and p hoto - detector diode. figure 2: device pad layout a maxim integrated products brand downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 2 1 ordering information part number description package phy1097-03ds-wr 2.5g tia bare die in waffle pack phy1097-03ds- fr 2.5g tia film on 10 wafer ring phy1097-03ds- qr 2.5g tia film on quarter 8 wafer ring 2 pad description number name type description 1 gnd 1 pwr connect to analog ground 2 pdc 1 analog regulated power supply to photodiode cathode 3 pda analog connect to photodiode anode, input to tia stage 4 pdc 2 analog regulated power supply to photodiode cathode 5 gnd 2 pwr connect to analog ground 6 rssi analog out received signal strength output. sources current equal to pd current 7 vcc 1 pwr 3.3 volt power supply connection 8 vcc 2 pwr 3.3 volt power supply connection 9 rx- analog out differential analog output pair with rx+ 10 gnd 3 gnd connect to analog ground 11 gnd 4 gnd connect to analog ground 12 gnd 5 gnd connect to analog ground 13 data_invert analog input inverts polarity of data output pins rx+ and rx- 14 gnd 6 gnd connect to analog ground 15 gnd 7 gnd connect to analog ground 16 gnd 8 gnd connect to analog ground 17 rx+ analog out differential analog outp ut pair with rx - 18 agc analog disables agc amplifier function when connected to gnd 19 vcc 3 pwr 3.3 volt power supply connection 20 vcc 4 pwr 3.3 volt power supply connection 21 rssi_dir analog input selects whether rssi output is a current sink or source. open circuit is a current sink, connect to ground for current source downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 3 3 device specifications 3.1 absolute maximum ratings exceeding these limits may cause permanent damage. correct operation under these condition s is not implied . extended periods of operation under these conditions may affect device reliabilit y. parameter conditions min max unit supply voltage -0.5 4.0 v maximum voltage on signal pins vcc within the maximum rating conditions -0.5 vcc + 0.5v v device operating temperature measured o n die +115 c storage temperature -55 150 c die attach temperature for a maximum 30 secs 400 c pda input current vcc > 3.0v 3.0 ma pda input current vcc < 3.0v 2.0 ma esd performance human body model (excluding pda pin) 2.0 kv human body model (pda pin) 0.5 kv 3.2 recommended operating conditions parameter conditions min max unit supply voltage 3.0 3.3 3.6 v current consumption including output termination 40 48 60 ma ambient operating temperature -40 95 c photodiode capacitance photodiode bias voltage 1.8v 1.0 pf 3.3 parametric performance all typical parameters are tested at 25 c and at vcc = 3.3v parameter conditions min typ max unit high-speed data input rate c in = 0.5pf 2.5 gbps sensitivity c in = 0.5pf, responsivity = 0.9 a/w, ber = 10 -10 , er = 10db -29 dbm input referred noise c in = 0.5pf, measured into a 1.866ghz, 4 th order bessel filter. 150 200 na rms small signal bandwidth (-3db) cpd = 0.35pf, -3db point at -27dbm, guaranteed by characterization of reference rosa a ssemblies. 1400 1700 mhz low frequency cut-off relative to 100mhz 25 35 khz gain variation with frequency 1mhz to 1250mhz, with respect to 100mhz input current < 500 a pp 2 db differential output swing 1 input current > 16 a pp 100 ? differential load, 2.5gbps 320 400 480 mvp -p downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 4 parameter conditions min typ max unit transimpedance (differential) input current <8 ap-p, 100 ? load 20k 25k 30k ? deterministic jitter k28.5 pattern 50 100 muip-p overshoot 2 7 -1prbs (wrt to average 0/1 level) 15 % undershoot 2 7 -1prbs (wrt average 0/1 level) 15 % input overload, a.c. dj within spec, er = 4.4 mapp input overload d.c. dj within spec, tj = 95 c 2.2 ma agc settling time 50 s output resistance differential vout+ to vout- 80 100 120 ? out put common mode voltage measured relative to vcc -0.5 -0.37 -0.25 v photodiode cathode voltage 2.5 2.6 2.7 v photodiode anode voltage 0.8 1.0 v rssi current accuracy measured relative to photodiode current 20 % rssi compliance voltage current sou rce mode 1.0 v current sink mode 0.8 v power supply rejection ratio 100khz C 4mhz 30 40 db 4 device description the phy1097 implements a complete analog front end, converting the photo - detector current, which has been modulated by light from an optical fibre, to a differential analog voltage signal. the phy1097 also provides a filtered bias current to the photo - detector to increase the level of component integration as well as the signal processing functions. 4.1 photodiode connection a pin photodiode s hould be connected to the phy1097 as shown in figure 3, using the internal voltage reference to bias the photodiode . the internal reference supplies a low noise output with high power supply rejection to 4 m hz. the voltage across the photodiode is equal to the power supply voltage, vpdc minus t he base emitter voltage of the input transistor on the phy1097, equal to vpda. the anode voltage, vpda is s ensitive to temperature and has a typical value of 0.8v. rssi pdc 1 pda mon 0v vpda vpdc vcc 3.3v phy 1097 internal voltage reference figure 3 C photodiode biased by internal voltage reg ulator downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 5 single ended connection of a pin photodiode to the pda input with an external bias supply can produce inconsistent sensitivity and bandwidth operation. if an avalanche photodiode (apd) is to be used this can be connected as shown in figure 4, filter ing of the bias voltage must be provided externally to the phy1097 to avoid damaging the device. the input current applied to the pda pad with vcc off (<3.0v) must not exceed the value given in the section 3.1 max imum ratings table, if exceeded damage may occur to the pda input. the rssi senses the mpd current from the pdc pad, this is not used in single ended applications such as apd. in this case a current mirror should be included on the apd bias to provide the rssi current. phy1097 vcc vpd 470pf 10nf apd 470pf figure 4 C connection of an avalanche photodiode 4.2 dc cancellation the removal of the direct current component of the input signal is necessary to reduce the pulse wi dth distortion for signals with a 50% mark density. the dc cancellation block provides low frequency feedback using an internally compensated ampli fier, removing the need for external compensation capacitors. 4.3 transimpedance amplifier (tia) the transimpedance (current to voltage) stage is a very low noise amplifier with a feedback resistor to set the gain. this stage features automatic gain control, where the transimpedance depends on the output signal level . this ensures that the output does not overload the subsequent stage in the signal pat h. an internal voltage regulator is used to power the front - end transimpedance amplifier in order to improve the rejection of power supply noise. 4.4 output data polarity the data polarity pin has an internal 8k ? pull - up resistor . i n normal non - inverting operation, where there is no external connection , the pin pulls to vdd. in this mode an optical '1' gives maximum input current and a voltage '1' on the positive output pin rx+ . c onnection of the pad to ground selects an inverted sense output. 4.5 output gain stage the output gain stage features a voltage amplifier, a single ended to differential converter and a s upply referenced differential output buffer. the phy1097 has a 50 ? single ended output impedance, which is suitable for the majority of applications. for optimum sup ply - noise rejection, the phy1097 should be terminated differentially. downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 6 4.6 received signal strength indication (rssi) the phy1097 provides a rssi output which can be used to measure the strength of the received optical signal. the photodiode current is proportional to the received optical power. the phy1097 generates an output current which is a mirror of the photodiode current at the pdc input and is valid only for differential photodiode connectio ns . the rssi output is a current sink or a current source . the direction of current flow is selected by using the rssi_dir bond. leaving this bond pad unco nnected selects a current sink, connecting this bond pad to ground selects a current source. an alternative method of measuring the received signal power is by using the received optical m odulation amplitude (oma). this method is provided by the phy2078 integrated bu r st mode laser driver and post amplifier device. downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 7 5 typical application r f voltage regulator pda vcc gnd pdc 1/2 amplifier signal detect & dc restore 50? agc amp 50? agc signal strength indicator rssi data _ invert o/p buffer rx + rx - rxin + rxin - cml output input amp low pass filter rxout - rxout + phy 2078 phy 1097 rssi _ dir figure 5 - typical applicatio n - g pon onu receiver path figure 5 shows a typ ical application for the phy1097 . in this application the output of the phy1097 is connected to the phyworks phy2078 pon laser driver and post amplifier circuit to form the receive path for a fibre optic module . the phy2078 provides the receive signal monitoring functions such as loss of signal and converts the input data into a variety of electrical formats. 5.1 layout and bonding in order to achieve the best performance it is necessary to minimise noise pickup and to reduce the effects of parasitic components. noise is picked up through the signal paths or through the power supply. noise at the input of the tia will be amplified and mixed with the wanted signal. this can be a result of noise pickup in the other components connected to the tia input , such as the photodiode, the capacitors and the bond wires. noise picked up in the signal path can be reduced by keeping bond wires short and by making sure the output and input bond wires are n ot clo se and are orthogonal to each other, power supply noise will be present as a result of the power supply design, the quality of decoupling precautions and pickup in the bond wires. to effectively de - couple supply rail noise to ground a capacitor may be placed inside the rosa to can. this should be placed as close as possible to the vcc pin on the tia. this reduces the effect of the bond wire inductance. noise on the power supply can also be a result of coupling between the tia output and the power sup ply. this coupling takes place between the output bond wires and the power supply bond wi res. as a result these must also be kept as short as possible and be routed orthogonally to each other. the phy1097 provides alternative bonding options through the replication of some device inputs and outputs, allowing a variety of rosa pin outs to be realised without compromis ing performance. for stable operation the ground bonds gnd1, gnd2, gnd4 and gnd7 should not be om itted. downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 8 6 mechanical specifications 6.1 to - can conn ections top- view: looking into the cd header. the diagrams below show an internal power supply decoupling capacitor and illustrate the optimum bondwire lengths and orientation. the value of the supply de - coupling capacitor should be 250 C 500 pf. vcc mon rx- rx+ photodiode capacitor p dc 1 p dc 2 p da g nd 1 g n d 2 r ss i 1 vc c 1 v cc 2 r x - g n d 3 g n d 4 g n d 5 g n d 7 g n d 6 d a ta _in v er t g nd 8 rx + ag c v cc 3 v cc 4 r ss i 2 phy1097 figure 6 - 5 pin rosa layout 1 vcc gnd rx- rx+ capacitor photodiode pd c 1 pd c 2 pd a gn d 1 g nd 2 rs si 1 v cc 1 vc c 2 r x - g nd 3 g nd 4 g nd 5 g nd 7 g nd 6 d at a_i n ve rt g n d 8 r x+ ag c vc c 3 vc c 4 rs si 2 phy1097 vcc gnd rx- rx+ photodiode capacitor p d c 1 p d c 2 p d a g n d1 g n d 2 r s si 1 v cc 1 v c c 2 rx - gn d 3 g nd 4 gn d 5 g nd 7 g nd 6 da ta _i nv er t g nd 8r x+ a gc v c c3v cc 4rs si 2 phy1097 figure 7 - 4 pin rosa layout 1 figure 8 C 4 pin rosa layout 2 downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 9 7 pad positions and sizes die size : 1100 m x 900 m thickness : 290 m +/ - 10 m pad opening: 80 m x 80 m measured between parallel sides number name pa d centres x y 1 gnd 1 -439.5 221.5 2 pdc 1 -439.5 113 3 pda -412.5 0 4 pdc 2 -439.5 -113 5 gnd 2 -439.5 -221.5 6 rssi -320.095 -339.5 7 vcc 1 -219.5 -339.5 8 vcc 2 -121.5 -339.5 9 agc 55.09 -339.5 10 rx- 222.1 -339.5 11 gnd 3 321.5 -339.5 12 gnd 4 439.5 -221.5 13 gnd 5 439.5 -123.5 14 data_invert 439.5 0 15 gnd 6 439.5 123.5 16 gnd 7 439.5 221.5 17 gnd 8 321.5 339.5 18 rx+ 222.1 339.5 19 vcc 3 -121.5 339.5 20 vcc 4 -219.5 339.5 21 rssi_dir -320.095 339.5 table 1: phy1097 pad coordinates figure 9 : phy1097 die image downloaded from: http:///
phy1097 - 03 -rd- 1. 5 datasheet page 10 maxim cannot assume responsibility for use of any circuitry other than circuitry enti rely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, inc. 1 60 rio robles , san jose , ca 95134 usa 1 - 408 - 601 - 10 00 ? 2011 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. 8 contact information for technical support, contact maxim at www.maxim - ic.com/support . disclaimer this datasheet contains preliminary information and is subject to change. this document does not transfer or license any intellectual property rights to the user. it does not imply any commit ment to produce the device described and is intended as a proposal for a new devic e. phyworks ltd assumes no liability or warranty for infringement of patent, copyright or other intel lectual property rights through the use of this product . phyworks ltd assumes no liability for fitness for particular use or claims arising from sale or use of its products. phyworks ltd products are not intended for use in life critical or sustai ning applications. downloaded from: http:///
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