general description the max24011 is a low-power and high-sensitivity 2.5gbps continuous mode transimpedance amplifier (tia) optimized for gpon fiber optic applications. the max24011 implements a complete analog front-end, converting the photo-detector current to a differential ana - log voltage signal. the max24011 has a low-noise front-end, an agc and typical differential transimpedance of 23k?. the max24011 also provides a filtered bias current to the photo detector cathode for internally biased pin applica - tions and a received signal strength indicator (rssi) out - put. the rssi is either derived from the current supplied by the pdc regulator, or represents the average current into the pda pin for use with externally biased photode - tectors, such as an apd. the max24011 is available in die form for mounting on a header to create a rosa when combined with suitable optics and photo-detector diode. applications gpon, onu receivers oc-48 transceiver modules beneits and features -33dbm (typ) sensitivity with apd up to 2.5gbps (nrz) data rates 190na rms (typ) input-referred noise automatic gain control of overload 31ma (typ) current consumption received signal strength indicator output from pda or pdc -40c to +95c operating temperature range ordering information appears at end of data sheet. for related parts and recommended products to use with this part, refer to www.maximintegrated.com/max24011.related . max24011 2.5gbps transimpedance amplifier 19-6654; rev 2; 5/14 rx+rx- v cco 50 i 50 i r f v cc rssi_sel rssi_out rssi_dir signal strengthindicator voltage regulator signal detect and dc restore amplifier o/p buffer pda gnd pdc o/p buffer agcamp max24011 functional diagram evaluation kit available downloaded from: http:///
voltage range on v cc ......................................... -0.3v to +4.0v voltage range on any pad not otherwise specified (with respect to gnd _ ) ....................... -0.3v to (gnd x +0.3v) maximum pda input current v cc ...................... 4ma operating maximum pda input current ............................................... 4ma operating temperature range ........................... -40c to +95c junction temperature ....................................... -55c to +150c storage temperature range ............................. -55oc to +150c die attach temperature (soldering, 10s) ......................... +400c soldering temperature (reflow) ....................................... +260c (v cc = 2.97v to +3.63v, t a = -40c to +95c.) (note 1) parameter symbol conditions min typ max units operating supply voltage v cc 2.97 3.3 3.63 v operating temperature -40 +95 c supply current v cc = 3.3v, output open circuit 31 ma parameter symbol conditions min typ max units power-supply rejection ratio (v dp - v dn )/v cc , 50khz to 4mhz; no v cc decoupling 15 db input bias voltage pda voltage 0.85 v minimum photodiode cathode bias pdc voltage 2.5 v transimpedance at 100mhz, input current < 9 a p-p 15 23 32.5 k output resistance differential 80 100 120 -3db bandwidth input current 2 a p-p , 100 differential output load, apd capacitance 0.35pf 1.8 ghz input-referred noise measured into 1.866ghz, 4th order bessel-thomson (bt) ilter, apd capacitance 0.35pf 190 na rms input overload ac dj < 220 mui p-p speciication 3.2 ma p-p deterministic jitter prbs 15 < 2.5ma p-p 100 200 mui p-p differential output swing input current 18a p-p to 3.6ma p-p , overload 200 320 mv p-p max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 2 absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. recommended dc operating conditions receiver characteristics downloaded from: http:///
note 1: electrical specifications are production tested at t a = +25c. specifications over the entire operating temperature range are guaranteed by design and characterization. typical specifications are at t a = +25c, 3.3v. receiver characteristics (continued) parameter symbol conditions min typ max units low-frequency -3db cutoff dc-coupled 5 30 khz gain flatness 100mhz to 1250mhz; latness referred to 100mhz; input current 500a p-p 2 db rssi accuracy dc input current 5a to 1.27ma (after single-point calibration) 20 % rssi gain 1 ma/ma maximum rssi compliance voltage rssi sourcing current (rssi_dir open circuit) v cc - 0.3 v minimum rssi compliance voltage rssi sinking current (rssi_dir connected to gnd) gnd + 0.45 v max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 3 downloaded from: http:///
pda pdc v cc n.c. d outp gnd gnd rssi_sel rssi_dir gnd gnd d outn n.c. n.c. n.c. rssi_out gndgnd gnd max24011 1 20 v cco gnd pin name dir type function 1, 4, 5, 11, 12, 15, 16 gnd power ground connect to ground 2 pdc o/p analog supplies bias voltage to internally biased pin photodiode cathode 3 pda i/p analog ampliier input which accepts input current from photodiode anode 6 rssi_out o/p analog outputs a current proportional to mean photodiode input current. sources current when rssi_dir is unconnected. 7 n.c. i/p analog no connection. do not connect. 8, 9, 19 n.c. no connection. do not connect. 10 d out n o/p analog negative cml output. positive current into pda causes voltage to fall on d out n pad. max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 4 pad description pad coniguration downloaded from: http:///
detailed description photodiode connection a pin photodiode should be connected to the max24011 as shown in figure 1, using the internal voltage reference to bias the photodiode. the voltage across the photodiode is equal to v pdc minus the base emitter voltage of the input transistor on the max24011, equal to v pda . the anode voltage, v pda is sensitive to temperature and has a typical value of 0.85v. to enable the internal regulator, pad 14 (rssi_ sel) needs to be bonded to ground. external connection of a pin photodiode cathode to an external power supply can produce inconsistent sensitiv - ity and bandwidth operation. if an avalanche photodiode is to be used this is con - nected as shown in figure 2, filtering of the bias voltage must be provided externally to the max24011 to avoid damaging the device. decoupling of the supply must also be provided in the optical assembly or host board. the input current applied to the pda pad with v cc off (< 3.0v) must not exceed the value given in the maximum ratings, if exceeded damage may occur to the pda input circuitry. decoupling for optimum sensitivity performance decoupling of pow - er-supply noise must be provided on the supply to the max24011 either in the optics assembly or on the main board that supplies power to the optics. further decou - pling and appropriate layout of the rssi support on the host board is also recommended to minimize noise injec - tion into the receive optical assembly. transimpedance ampliier (tia) the transimpedance (current to voltage) stage is a very low noise amplifier with a feedback resistor to set the gain. this ensures that the output does not overload the subsequent stage in the signal path. an internal voltage regulator is used to power the front- end transimpedance amplifier to improve the rejection of power-supply noise. pin name dir type function 13 rssi_dir i/p analog selects rssi_out pad to source current when unconnected and sink current when connected to ground. 14 rssi_sel i/p analog connecting this pad to ground causes the rssi current to be measured from the photodiode cathode and the pdc regulator to be enabled. this option can only be used when the pdc pad is connected to the photodiode cathode. 17 d out p o/p analog positive cml output. positive current into pda causes voltage to rise on d out p pad 18 v cco power supply connect to power supply 20 v cc power supply connect to power supply max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 5 pad description (continued) downloaded from: http:///
output gain stage the output gain stage features a voltage amplifier, a single ended to differential converter and a supply-refer - enced differential output buffer. the max24011 has a 50? single-ended output imped - ance, which is suitable for the majority of applications. for optimum supply-noise rejection, the max24011 should be terminated differentially. received signal strength indication (rssi) the max24011 provides a rssi output, which measures the strength of the received optical signal. the photodiode current is proportional to the received optical power. the max24011 generates an output current that is a copy of the photodiode current. this is configured for internal or external biased photodiodes using rssi_sel. 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 unconnected selects a current source, connecting this bond pad to ground selects a current sink. application diagrams the max24011 can be bonded in 5-pin (no rssi) or 6-pin (with rssi) headers using an externally biased apd. alternatively, it can be bonded in 4-pin (no rssi) or 5-pin (with rssi) headers using an internally biased pin photodiode. keep the doutp bondwire as orthogonal as possible to v cc power bondwires to reduce coupling. the capaci - tor c2 is needed for decoupling of the apd voltage and should be appropriately rated for maximum v apd . figure 1. photodiode biased by internal voltage regulator figure 2. connection of an avalanche photodiode rssi pdc pda mon 0v c int r int v cc 3.3v v pda v pdc internal voltage reference max24011 rssi_out pdc pda mon 0v c in c ext r int v cc 3.3v v apd v pda v pdc internal voltage reference r ext c supply max24011 max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 6 downloaded from: http:///
figure 3. externally biased apd mounted on a 6-pin to-can header with rssi output figure 4. internally biased pin photodiode mounted on a 5-pin to-can header with rssi output d outp d outn rssi dia = 2.54mm c2 (330pf) c1 (470pf) dia = 4.22mmdia = 5.31mm die schott sl 04.928.018 to-46 header . apd onsub- amount v pd v cc this diagram is to scale, but bondwire sizes are only approximate. bondwires are curved in vertical plane. functional wires are up to ~50% longer than drawn. ground wires are 2x ro 3x longer than drawn dia = 0.35mm doutp doutn v cc rssi dia=2.54mm dia=4.22mmdia=5.31mm dia=0.44mm dia=1.17mm die schott sl 04.769.018to-46 header this diagram is to scale, but bondwire sizes are only approximate. bondwires are curved in vertical plane. functional wires are up to ~50% longer than drawn. ground wires are 2x to 3x longer than drawn. c1 max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 7 downloaded from: http:///
pad position and sizes typical sawn die size (chip extent): 1211 um x 901 um number name pad centers x y 1 gnd 45 603 2 pdc 45 505 3 pda 70 384 4 gnd 45 263 5 gnd 45 165 6 rssi_out 165 45 7 n.c. 263 45 8 n.c. 409 45 9 n.c. 555 45 10 d out n 705 45 11 gnd 903 45 12 gnd 1023 165 13 rssi_dir 1023 311 14 rssi_sel 1023 457 15 gnd 1023 603 16 gnd 903 723 17 d out p 705 723 18 v cc 454 723 19 n.c. 263 723 20 v cc 165 723 max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 8 downloaded from: http:///
+denotes a lead(pb)-free/rohs-compliant package. part temp range pin-package max24011e/d+ -40 c to +95 c dice max24011 2.5gbps transimpedance ampliier www.maximintegrated.com maxim integrated 9 chip information process: bicmos ordering information downloaded from: http:///
revision number revision date description pages changed 0 3/13 initial release 1 9/13 revised figure 4 7 2 5/14 made corrections in electrical characteristics 2, 3 maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and speciications without n otice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. max24011 2.5gbps transimpedance ampliier ? 2014 maxim integrated products, inc. 10 revision history for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com. downloaded from: http:///
|
