general description the max4951 dual-channel buffer is designed to re-drive serial-ata (sata) i and sata ii signals and is functional up to 6.0gbps for next-generation data rates. the max4951 can be placed near an esata connector to overcome board losses and produce an esata-compati- ble signal level. the max4951 preserves signal integrity at the receiver by reestablishing full output levels, and can reduce the total system jitter (t j ) by squaring up the signal. this device features channel-independent digital boost controls to drive sata outputs over longer trace lengths, or to meet esata specifications. sata out-of-band (oob) signaling is supported using high-speed amplitude detection on the inputs, and squelch on the corresponding outputs. inputs and outputs are all internally 50 ? terminated and must be ac-coupled to the sata controller ic and sata device. the max4951 operates from a single +3.3v (typ) sup- ply and is available in a small, 4mm x 4mm, tqfn package with flow-through traces for ease of layout. this device is specified over the 0? to +70? operat- ing temperature range. applications servers desktop computers notebook computers docking stations data storage/workstations features single +3.3v (typ) supply operation supports sata i (1.5gbps) and sata ii (3.0gbps) supports up to 6.0gbps for next-generation applications meets sata i, sata ii input-/output-return loss mask supports esata levels supports sata out-of-band (oob) signaling internal input/output 50 ? ? termination resistors inline signal traces for flow-through layout esd protection on all pins: ?.5kv space-saving, 4mm x 4mm, tqfn package max4951 sata i/sata ii bidirectional re-driver ________________________________________________________________ maxim integrated products 1 ordering information 19-4178; rev 1; 5/09 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. + denotes a lead(pb)-free/rohs-compliant package. * ep = exposed pad. part temp range pin-package MAX4951CTP+ 0? to +70? 20 tqfn-ep * pin configuration 19 20 18 17 7 6 8 ham hbp 9 hap dam dbm dbp dap 1 2 gnd 45 15 14 12 11 gnd v cc ba bb en v cc max4951 gnd gnd 3 13 gnd 16 10 v cc v cc tqfn 4mm x 4mm top view hbm *ep *connect exposed pad (ep) to gnd.
max4951 sata i/sata ii bidirectional re-driver 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v cc = +3.0v to +3.6v, c l = 10nf, r l = 50 ? , t a = 0? to +70?, unless otherwise noted. typical values are at v cc = +3.3v, t a = +25?.) (note 3) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. (voltages referenced to gnd.) v cc ........................................................................-0.3v to +4.0v hap, ham, dbp, dbm, en, ba, bb (note 1)...................................................-0.3v to (v cc + 0.3v) short-circuit output current (hbp, hbm, dap, dam) .................................................90ma continuous current at inputs (hap, ham, dbp, dbm) ...............................................?0ma continuous current (en, ba, bb) ...................................................................?ma continuous power dissipation (t a = +70?) 20-pin tqfn (derate 25.6mw/? above +70?) ..... 2051mw junction-to-case thermal resistance ( jc ) (note 2) 20-pin tqfn...................................................................6?/w junction-to-ambient thermal resistance ( ja ) (note 2) 20-pin tqfn.................................................................39?/w operating temperature range...............................0? to +70? storage temperature range .............................-55? to +150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units operating power-supply range v cc 3.0 3.6 v ba = bb = v cc 90 125 operating supply current i cc ba = bb = gnd 70 100 ma standby supply current i stby en = gnd 7 10 ma single-ended input resistance z rx-se-dc 40 ? differential input resistance z rx-diff-dc 85 100 115 ? single-ended output resistance z tx-se-dc 40 ? differential output resistance z tx-diff-dc 85 100 115 ? ac performance f = 150mhz to 300mhz -29 -18 f = 300mhz to 600mhz -26 -14 f = 600mhz to 1200mhz -22 -10 f = 1.2ghz to 2.4ghz -18 -8 f = 2.4ghz to 3.0ghz -15 -3 differential input return loss (note 4) rl rx-diff f = 3.0ghz to 5.0ghz -14 -1 db f = 150mhz to 300mhz -5 f = 300mhz to 600mhz -5 f = 600mhz to 1200mhz -2 f = 1.2ghz to 2.4ghz -2 f = 2.4ghz to 3.0ghz -2 common-mode input return loss (note 4) rl rx-cm f = 3.0ghz to 5.0ghz -1 db note 1: all i/o pins are clamped by internal diodes. note 2: package thermal resistances were obtained using the method described in jedec specification jesd51-7, using a four-layer board. for detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial .
max4951 sata i/sata ii bidirectional re-driver _______________________________________________________________________________________ 3 electrical characteristics (continued) (v cc = +3.0v to +3.6v, c l = 10nf, r l = 50 ? , t a = 0? to +70?, unless otherwise noted. typical values are at v cc = +3.3v, t a = +25?.) (note 3) parameter symbol conditions min typ max units f = 150mhz to 300mhz -32 -14 f = 300mhz to 600mhz -26 -8 f = 600mhz to 1200mhz -21 -6 f = 1.2ghz to 2.4ghz -16 -6 f = 2.4ghz to 3.0ghz -15 -3 differential output return loss (note 4) rl tx-diff f = 3.0ghz to 5.0ghz -13 -1 db f = 150mhz to 300mhz -8 f = 300mhz to 600mhz -5 f = 600mhz to 1200mhz -2 f = 1.2ghz to 2.4ghz -2 f = 2.4ghz to 3.0ghz -2 common-mode output return loss (note 4) rl tx-cm f = 3.0ghz to 5.0ghz -1 db differential input signal range v rx-dff-pp sata 1.5gbps/3.0gbps 220 1600 mv p-p ba = bb = gnd 450 525 650 differential output swing v tx-dff-pp f = 750mhz ba = bb = v cc 770 930 1144 mv p-p propagation delay t pd 240 ps output rise/fall time t r (notes 4, 5) 60 ps deterministic jitter t tx-dj-dff up to 6.0gbps (notes 4, 6) 15 ps p-p random jitter t tx-rj-dff up to 6.0gbps (notes 4, 6) 1.8 ps rms oob detector threshold v th-oob sata oob 50 150 mv p-p oob output startup/shutdown time t oob (note 7) 2 5 ns ba = bb = gnd -35 crosstalk ctk f 1.5ghz ba = bb = v cc -30 db logic input input logic-high v ih 1.4 v input logic-low v il 0.6 v input logic hysteresis v hyst 0.1 v esd protection all pins human body model ?.5 kv note 3: all devices are 100% production tested at t a = +70?. all temperature limits are guaranteed by design. note 4: guaranteed by design. note 5: rise and fall times are measured using 20% and 80% levels. note 6: dj measured using k28.5 pattern; rj measured using k28.7 pattern. note 7: total time for oob detection circuit to enable/squelch the output.
max4951 sata i/sata ii bidirectional re-driver 4 _______________________________________________________________________________________ typical operating characteristics (v cc = 3.3v, t a = +25?, all eye diagrams measured using k28.5 pattern.) ba = bb = gnd eye diagram (v rx-dff-pp = 220mv p-p , 1.5gbps) max4951 toc01 100mv/div 200ps/div eye diagram voltage (mv) 400 200 -400 -200 0 -300 -200 -100 0 100 200 300 -600 600 ba = bb = gnd eye diagram (v rx-dff-pp = 220mv p-p , 3.0gbps) max4951 toc02 100mv/div 100ps/div eye diagram voltage (mv) 200 100 -200 -100 0 -300 -200 -100 0 100 200 300 -300 300 ba = bb = gnd eye diagram (v rx-dff-pp = 220mv p-p , 6.0gbps) max4951 toc03 100mv/div 50ps/div eye diagram voltage (mv) 100 50 -100 -50 0 -300 -200 -100 0 100 200 300 -150 150 ba = bb = gnd eye diagram (v rx-dff-pp = 1600mv p-p , 1.5gbps) max4951 toc04 100mv/div 200ps/div eye diagram voltage (mv) 400 200 -400 -200 0 -300 -200 -100 0 100 200 300 -600 600 ba = bb = gnd eye diagram (v rx-dff-pp = 1600mv p-p , 3.0gbps) max4951 toc05 100mv/div 100ps/div eye diagram voltage (mv) 200 100 -200 -100 0 -300 -200 -100 0 100 200 300 -300 300 ba = bb = gnd eye diagram (v rx-dff-pp = 1600mv p-p , 6.0gbps) max4951 toc06 100mv/div 50ps/div eye diagram voltage (mv) 100 50 -100 -50 0 -300 -200 -100 0 100 200 300 -150 150 ba = bb = v cc eye diagram (v rx-dff-pp = 220mv p-p , 1.5gbps) 200ps/div eye diagram voltage (mv) 400 200 0 -200 -400 -400 -200 0 200 400 600 -600 -600 600 max4951 toc07 200mv/div ba = bb = v cc eye diagram (v rx-dff-pp = 220mv p-p , 3.0gbps) max4951 toc08 100ps/div eye diagram voltage (mv) 200 100 0 -100 -200 -500 -400 -300 -200 -100 0 100 200 300 400 500 -300 300 200mv/div ba = bb = v cc eye diagram (v rx-dff-pp = 220mv p-p , 6.0gbps) max4951 toc09 50ps/div eye diagram voltage (mv) 100 50 0 -50 -100 -500 -400 -300 -200 -100 0 100 200 300 400 500 -150 150 200mv/div
max4951 sata i/sata ii bidirectional re-driver _______________________________________________________________________________________ 5 typical operating characteristics (continued) (v cc = 3.3v, t a = +25?, all eye diagrams measured using k28.5 pattern.) ba = bb = v cc eye diagram (v rx-dff-pp = 1600mv p-p , 1.5gbps) max4951 toc10 200ps/div eye diagram voltage (mv) 400 200 0 -200 -400 -600 600 200mv/div -400 -200 0 200 400 600 -600 ba = bb = v cc eye diagram (v rx-dff-pp = 1600mv p-p , 3.0gbps) max4951 toc11 100ps/div eye diagram voltage (mv) 200 100 0 -100 -200 -300 300 200mv/div -400 -200 0 200 400 600 -600 ba = bb = v cc eye diagram (v rx-dff-pp = 1600mv p-p , 6.0gbps) max4951 toc12 50ps/div eye diagram voltage (mv) 100 50 0 -50 -100 -150 150 200mv/div -400 -200 0 200 400 600 -600 differential input return loss vs. frequency frequency (ghz) differential input return loss (db) max4951 toc13 012345 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 max4951 sata mask differential output return loss vs. frequency frequency (ghz) differential output return loss (db) max4951 toc14 012345 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 max4951 sata mask
max4951 detailed description the max4951 consists of two identical buffers that take sata input signals and return them to full output levels. this device functions up to 6.0gbps for next-generation sata applications. input/output terminations inputs and outputs are internally 50 ? terminated to v cc (see the functional diagram/truth table ) and must be ac-coupled to the sata controller ic and sata device for proper operation. out-of-band logic the max4951 provides full out-of-band (oob) signal support through high-speed amplitude detection cir- cuitry. sata oob differential input signals of 50mv p-p or less are detected as off and not passed to the out- put. this prevents the system from responding to unwanted noise. sata oob differential input signals of 150mv p-p or more are detected as on and passed to the output. this allows oob signals to transmit through the max4951. the time for the amplitude detection cir- cuit to detect an inactive sata oob input and squelch the associated output, or detect an active sata oob input and enable the output, is less than 5ns. enable input the max4951 features an active-high enable input (en). en has an internal pulldown resistor of 70k ? (typ). when en is driven low or left unconnected, the max4951 enters low-power standby mode and the buffers are dis- abled. drive en high for normal operation. output boost selection inputs the max4951 has two digital control logic inputs, ba and bb. ba and bb have internal pulldown resistors of 70k ? (typ). ba and bb control the boost level of their corresponding buffers (see the functional diagram/ truth table ). drive ba or bb low or leave unconnected for standard sata output levels. drive ba or bb high to boost the output. the boosted output level compen- sates for attenuation from longer trace-length cables or to meet esata specifications. applications information figure 3 shows a typical application circuit with the max4951 used to drive an esata output. the diagram assumes that the max4951 is close to the sata host controller. bb is set low to drive standard sata levels to the host, and ba is set high to drive esata levels to the device. if the max4951 is further from the controller, set bb high to compensate for attenuation. sata i/sata ii bidirectional re-driver 6 _______________________________________________________________________________________ pin description pin name function 1 hap noninverting input from host channel a 2 ham inverting input from host channel a 3, 13, 17, 18, 19 gnd ground 4 hbm inverting output to host channel b 5 hbp noninverting output to host channel b 6, 10, 16, 20 v cc positive supply voltage input. bypass v cc to gnd with 0.1? and 0.001? capacitors in parallel and as close to the device as possible. 7en active-high enable input. drive en low to put device in standby mode. drive en high for normal operation. en is internally pulled down. 8bb channel-b boost enable input. drive bb high to enable channel-b output boost. drive bb low for standard sata output level. bb is internally pulled down. 9ba channel-a boost enable input. drive ba high to enable channel-a output boost. drive ba low for standard sata output level. ba is internally pulled down. 11 dbp noninverting input from device channel b 12 dbm inverting input from device channel b 14 dam inverting output to device channel a 15 dap noninverting output to device channel a ?p exposed pad. internally connected to gnd. ep must be electrically connected to a ground plane for proper thermal and electrical operation.
exposed-pad package the exposed-pad, 20-pin, tqfn package incorporates features that provide a very low thermal-resistance path for heat removal from the ic. the exposed pad on the max4951 must be soldered to gnd for proper thermal and electrical performance. for more information on exposed-pad packages, refer to maxim application note hfan-08.1: thermal considerations of qfn and other exposed-paddle packages . layout use controlled-impedance transmission lines to inter- face with the max4951 high-speed inputs and outputs. place power-supply decoupling capacitors as close as possible to v cc . esd protection as with all maxim devices, esd-protection structures are incorporated on all pins to protect against electro- static discharges encountered during handling and assembly. the max4951 is protected against esd up to ?.5kv (human body model) without damage. the esd structures withstand ?.5kv in all states: normal operation and powered down. after an esd event, the max4951 continues to function without latchup. max4951 sata i/sata ii bidirectional re-driver _______________________________________________________________________________________ 7 functional diagram/truth table v cc v cc 50 ? 50 ? v cc 50 ? 50 ? v cc 50 ? 50 ? v cc 50 ? 50 ? control logic max4951 dap hap dam ham dbm hbm dbp hbp bb en ba gnd x = don? care max4951 en ba bb channel a channel b 0 x x standby standby 1 0 0 standard sata standard sata 1 1 0 boost standard sata 1 0 1 standard sata boost 1 1 1 boost boost
max4951 human body model the max4951 is characterized for ?.5kv esd protec- tion using the human body model (mil-std-883, method 3015). figure 1 shows the human body model and figure 2 shows the current waveform it generates when discharged into a low impedance. this model consists of a 100pf capacitor charged to the esd volt- age of interest that is then discharged into the device through a 1.5k ? resistor. power-supply sequencing caution: do not exceed the absolute maximum rat- ings because stresses beyond the listed ratings may cause permanent damage to the device. proper power-supply sequencing is recommended for all devices. always apply v cc before applying signals, especially if the signal is not current limited. sata i/sata ii bidirectional re-driver 8 _______________________________________________________________________________________ figure 2. human body current waveform i p 100% 90% 36.8% t rl time t dl current waveform peak-to-peak ringing (not drawn to scale) i r 10% 0 0 amps charge-current limit resistor discharge resistance storage capacitor c s 100pf r c 1m ? r d 1500 ? high- voltage dc source device under test figure 1. human body esd test model
max4951 sata i/sata ii bidirectional re-driver 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. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 _____________________ 9 2009 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. max4951 en gpio +3.3v 0.001 f 0.1 f gnd bb ba +3.3v sata host controller esata device connector rx tx 10nf (x7r) 10nf (x7r) 10nf (x7r) 10nf (x7r) 10nf (x7r) 10nf (x7r) 10nf (x7r) 10nf (x7r) hap ham hbm hbp dap dam dbm dbp tx rx figure 3. typical application circuit package information for the latest package outline information, go to www.maxim-ic.com/packages . package type package code document no. 20 tqfn-ep t2044-2 21-0139 chip information process: bicmos revision history revision number revision date description pages changed 0 6/08 initial release 1 5/09 updated features , electrical characteristics table, applications information section, and added esd protection and human body model sections. 1, 3, 6, 7, 8
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