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_______________________________________________________________ maxim integrated products 1 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com. max14978 superspeed usb passive switch (low/full/hi/superspeed) 19-5573; rev 1; 4/11 typical operating circuit general description the max14978 high-performance, passive analog switch is ideal for switching hi-speed usb and superspeed usb data between one source and two loads, or vice versa. the device can be used in desktop and notebook applications where superspeed usb ports are in limited supply. the device consists of two sets of analog switches with one set used for usb low-speed, full-speed, and hi-speed signals and the second set used for usb superspeed. the device operates from a single +3.3v supply. the device features low insertion loss for all speeds. it has q 6kv human body model (hbm) esd protection on all i/o pins. in addition, the low/full/hi-speed com_ ports have esd protection to q 15kv hbm and q 8kv iec 61000-4-2 contact. the device is available in a small, 3.5mm x 9.0mm, 42-pin tqfn package and is specified over the extend - ed -40 n c to +85 n c temperature range. applications desktop pcs laptop pcs industrial usb switching features s designed for superspeed usb applications: low/full/hi-speed ( 1.5/12/480mbps) superspeed (5.0gbps) s superior return loss and insertion loss for superspeed analog switches s low quiescent current: 36a (typ) s all link training is preserved (superspeed) s lvcmos control (1.4v p v ih p 3.6v) s operation from a single +3.3v power supply s small, 3.5mm x 9.0mm, 42-pin tqfn package ordering information + denotes a lead(pb)-free/rohs-compliant package. * ep = exposed pad. max14978 sel1 sel2 gnd v cc v dd +3.3v ncd+ ncd- d+ superspeed usb por t1 usb switch controller d- tx+ tx- rx+ rx- d+ superspeed usb controller d- tx+ tx- rx+ rx- d+ superspeed usb por t2 d- tx+ tx- rx+ rx- nod+ nod- comd+ 0.1f comd- com0+ com0- com1+ com1- nc0+ nc0- nc1+ nc1- no0+ no0- no1+ no1- en part temp range pin-package MAX14978ETO+ -40 n c to +85 n c 42 tqfn-ep*
max14978 superspeed usb passive switch (low/full/hi/superspeed) 2 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. (all voltages referenced to gnd, unless otherwise noted.) v cc ....................................................................... -0.3v to +6.0v v dd ....................................................................... -0.3v to +4.0v sel1, en , comd_, nod_, ncd_ (note 1) ...................................... -0.3v to (v cc + 0.3v) sel2, com0_, com1_, nc0_, nc1_, no0_, no1_ (note 1) ............... -0.3v to (v dd + 0.3v) |com0_ - no0_|, |com0_ - nc0_|, |com0 _ - no1 _|, |com0 _ - nc1_| (note 1) ........ 0 to +2.0v continuous current (com0_, com1_ to no0_, no1_, nc0_, nc1_) ........................ q 70ma peak current (com0_, com1_ to no0_, no1_, nc0_, nc1_) (pulsed at 1ms, 10% duty cycle) ................................. q 70ma continuous current into any terminal ............................ q 30ma continuous power dissipation (t a = +70 n c) tqfn (derate 35.7mw/ n c above +70 n c) .................. 2857mw operating temperature range .......................... -40 n c to +85 n c storage temperature range ............................ -65 n c to +150 n c junction temperature ..................................................... +150 n c lead temperature (soldering, 10s) ................................ +300 n c soldering temperature (reflow) ...................................... +260 n c electrical characteristics (v cc = +3.0v to +5.5v, v dd = +3.0v to +3.6v, t a = -40 n c to +85 n c, unless otherwise noted. typical values are at v cc = v dd = +3.3v, t a = +25 n c.) (note 2) absolute maximum ratings note 1: signals on sel_, no_, nc_, or com_ exceeding v cc , v dd , or v gnd are clamped by internal diodes. limit forward-diode current to maximum current rating. parameter symbol conditions min typ max units power-supply range v cc 3.0 5.5 v v dd 3.0 3.6 supply current i cc v sel1 = 0v or v cc , v en = 0v v cc = 3.0v 0.6 1.5 f a i dd v sel2 = 0v or v dd v dd = 3.3v 60 shutdown supply current, i cc i shdn hi-speed usb switches, switch disabled (v en = v cc ) 0.1 f a increase in supply current, i cc , with v sel1 , v en voltage hi-speed usb switches, 0v p v sel1 p v il or v ih p v sel1 p v cc or 0v p v en p v il or v ih p v en p v cc 1 f a analog signal range v com_ , v no_ , v nc_ hi-speed usb switches, v en = 0v (note 3) 0 v cc v superspeed usb switches -0.3 v dd - 1.2 fault-protection trip threshold v fp hi-speed usb switches, comd_ only, t a = +25 n c v cc + 0.6 v cc + 0.8 v cc + 1 v on-resistance r on hi-speed usb switches, v comd_ = 0v to v cc 5 10 i hi-speed usb switches, v cc = 3.0v, v comd_ = 3.6v 5.5 superspeed usb switches, v dd = 3.0v, i com_ = 15ma, v no_ = v nc_ = 0v, 1.8v 7
max14978 superspeed usb passive switch (low/full/hi/superspeed) 3 electrical characteristics (continued) (v cc = +3.0v to +5.5v, v dd = +3.0v to +3.6v, t a = -40 n c to +85 n c, unless otherwise noted. typical values are at v cc = v dd = +3.3v, t a = +25 n c.) (note 2) parameter symbol conditions min typ max units on-resistance match between channels d r on hi-speed usb switches, v cc = 3.0v, v comd_ = 2.0v (notes 4, 5) 0.1 1 i superspeed usb switches, v dd = 3.0v, i com_ = 15ma, v no_ or v nc_ = 0v (notes 4, 5) 0.6 2 on-resistance match between pairs of same channels d r on superspeed usb switches, v dd = 3.0v, i com_ = 15ma, v no_ or v nc_ = 0v (notes 4, 5) 0.1 1 i on-resistance flatness r flat hi-speed usb switches, v cc = 3.0v, v comd_ = 0v to v cc (note 6) 0.1 i superspeed usb switches, v dd = 3.0v, i com_ = 15ma, v no_ or v nc_ = 0v (notes 5, 6) 0.06 2 off-leakage current i com(off) hi-speed usb switches, v cc = 5.5v, v comd_ = 0v or 5.5v, v nod_ , v ncd_ = 5.5v or 0v -250 +250 na superspeed usb switches, v dd = 3.6v, v com_ = 0v, 1.8v; v no_ or v nc_ = 1.8v, 0v -1 +1 f a on-leakage current i com(on) hi-speed usb switches, v cc = 5.5v, v comd_ = 0v or 5.5v, v nod_ , v ncd_ = unconnected -250 +250 na superspeed usb switches, v dd = 3.6v, v com_ = 0v, 1.8v; v no_ or v nc_ = v com_ or unconnected -1 +1 f a ac performance on-channel -3db bandwidth bw hi-speed usb switches, r l = r s = 50 i , signal = 0dbm 950 mhz on-loss g loss superspeed usb switches, r l = r s = 50 i , unbalanced 1mhz < f < 100mhz -0.5 db 500mhz < f < 1.25ghz -1.4 off-isolation v iso hi-speed usb switches, v nod_ , v ncd_ = 0dbm, r l = r s = 50 i , figure 1 f = 10mhz -48 db f = 250mhz -20 f = 500mhz -17 superspeed usb switches, signal = 0dbm, r s = r l = 50 i f = 10mhz -56 f = 1.25ghz -26
max14978 superspeed usb passive switch (low/full/hi/superspeed) 4 electrical characteristics (continued) (v cc = +3.0v to +5.5v, v dd = +3.0v to +3.6v, t a = -40 n c to +85 n c, unless otherwise noted. typical values are at v cc = v dd = +3.3v, t a = +25 n c.) (note 2) parameter symbol conditions min typ max units crosstalk (note 7) v ct hi-speed usb switches, v nod_ , v ncd_ = 0dbm, r l = r s = 50 i , figure 1 f = 10mhz -73 db f = 250mhz -54 f = 500mhz -33 superspeed usb switch - es, crosstalk between any two pairs, r s = r l = 50 i , unbal - anced, figure 1 f = 50mhz -53 f = 1.25ghz -32 signaling data rate br superspeed usb switches, r s = r l = 50 i 5.0 gbps logic input input logic-high v ih 1.4 v input logic-low v il 0.5 v input leakage current i in hi-speed usb switches -250 +250 na superspeed usb switches, v sel2 = 0v or v dd -1 +1 f a input logic hysteresis v hyst superspeed usb switches 100 mv dynamic performance turn-on time t on hi-speed usb switches, v nod _ or v ncd_ = 1.5v, r l = 300 i , c l = 35pf, v en = v cc to 0v, figure 2 20 100 f s superspeed usb switches, v no_ or v nc_ = 1.0v, r l = 50 i , figure 2 90 250 ns turn-off time t off v nod_ or v ncd_ = 1.5v, r l = 300 i , c l = 35pf, v en = 0v to v cc , figure 2 1 5 f s superspeed usb switches, v no_ or v nc_ = 1.0v, r l = 50 i , figure 2 10 50 ns propagation delay t plh , t phl hi-speed usb switches, r l = r s = 50 i , figure 3 100 ps superspeed usb switches, r l = r s = 50 i 50 output skew between switches t sk hi-speed usb switches, skew between switch 1 and 2, r l = r s = 50 i , figure 3 40 ps output skew between pairs t sk1 superspeed usb switches, r s = r l = 50 i , unbalanced; skew between any two pairs, figure 3 50 ps output skew between same pair t sk2 superspeed usb switches, r s = r l = 50 i , unbalanced; skew between two lines on same pair, figure 3 10 ps fault-protection response time t fp hi-speed usb switches, v comd_ = 0v to 5v step, r l = r s = 50 i , v cc = 3.3v, figure 4 0.5 5.0 f s
max14978 superspeed usb passive switch (low/full/hi/superspeed) 5 note 2: all devices are 100% production tested at t a = +25 n c. all temperature limits are guaranteed by design. note 3: the switch turns off for voltages above v fp , protecting downstream circuits in case of a fault condition. note 4: d r on(max) = |r on(ch1) - r on(ch2) |. note 5: guaranteed by design. not production tested. note 6: flatness is defined as the difference between the maximum and minimum value of on-resistance, as measured over spec - ified analog-signal ranges. note 7: between any two switches. electrical characteristics (continued) (v cc = +3.0v to +5.5v, v dd = +3.0v to +3.6v, t a = -40 n c to +85 n c, unless otherwise noted. typical values are at v cc = v dd = +3.3v, t a = +25 n c.) (note 2) parameter symbol conditions min typ max units fault-protection recovery time t fpr hi-speed usb switches, v comd_ = 5v to 0v step, r l = r s = 50 i , v cc = 3.3v, figure 4 100 f s no_ or nc_ off-capacitance c no(off) or c nc(off) hi-speed usb switches, f = 1mhz, figure 5 2 pf superspeed usb switches, figure 5 1 com_ off-capacitance c com(off) hi-speed usb switches, f = 1mhz, figure 5 5.5 pf hi-speed usb switches, f = 240mhz, figure 5 4.8 com_ on-capacitance c com(on) hi-speed usb switches, f = 1mhz, figure 5 6.5 pf hi-speed usb switches, f = 240mhz, figure 5 5.5 superspeed usb switches, figure 5 2 total harmonic distortion plus noise thd+n hi-speed usb switches, v comd _ = 1v p-p , v bias = 1v, r l = r s = 50 i , f = 20hz to 20khz 0.03 % esd protection comd+, comd- human body model 15 kv iec 61000-4-2 air gap discharge 15 iec 61000-4-2 contact discharge 8 com0_, com1_ human body model 6 kv all pins human body model 2 kv
max14978 superspeed usb passive switch (low/full/hi/superspeed) 6 test circuits/timing diagrams figure 1. off-isolation, on-loss, and crosstalk figure 2. switching time measurements are standardized against shorts at ic terminals. off-isolation is measured between com_ and "off" no_ or nc_ terminal on each switch. on-loss is measured between com_ and "on" no_ or nc_ terminal on each switch. crosstalk is measured between any two pairs. signal direction through switch is reversed; worst values are recorded. v dd v out v dd sel_ nc_ com_ no_ v in v cc v cc off-isolation = 20log v out v in on-loss = 20log v out v in crosstalk = 20log v out v in network analyzer 50 50 50 50 meas ref 0.1 f 0.1 f 0v or v dd 50 gnd max14978 t r < 5n s t f < 5n s 50% v il logic input v n_ = v no_ or v nc_ r l com_ gnd sel_ c l includes fixture and stray capacitance. v n_ v ih t off 0v no_ or nc_ 0.9 x v 0ut 0.9 x v out t on v out switch output logic input c l v out = v n_ ( ) r l r l + r on v out max14978 v cc v cc v dd v dd 0.1 f 0.1 f
max14978 superspeed usb passive switch (low/full/hi/superspeed) 7 test circuits/timing diagrams (continued) figure 3. propagation delay, output skew in+ in- out+ out- v in+ v in- v out+ v out- no_+ or nc_+ no_- or nc_- sel_ com_+ com_ - 0v +1.5v 0v +1.5v 0v +1.5v 0v +1.5v t plhx t phlx t inrise t outrise t outfall rise-time propagation delay = t plhx or t plhy fall-time propagation delay = t phlx or t phly t sk1 = difference in propagation delay (rise-fall) 50% 50% 50% 50% 90% 10% 10% 90% 10% 10% r l r l 50% 50% 50% 50% t infall 90% 90% t phly t plhy r s r s between two lines on the same pair between any two pairs t sk2 = | t plhx - t phly | or | t phlx - t plhy | max14978 v cc v cc v dd v dd 0.1 f 0.1 f
max14978 superspeed usb passive switch (low/full/hi/superspeed) 8 test circuits/timing diagrams (continued) figure 4. fault protection response/recovery time figure 5. channel off-/on-capacitance typical operating characteristics (v cc = v dd = 3.3v, t a = +25 n c, unless otherwise noted.) v fp v cc = +3.3v t fp t fpr +5v +3v 0v +3v 0v v comd_ v nod_ v ncd_ capacitance meter nc_ or no_ com_ gnd sel_ v il or v ih 0.1f 0.1f v dd v dd v cc v cc max14978 eye diagram (v cc = +3.3v, f = 2.5ghz, r s = r l = 50 ) ps/div voltage (mv) 150 200 100 0 50 -150 -100 -50 -200 -800 -600 -400 -200 0 200 400 600 800 max14978 toc01 eye: all bit s uls: 9995/9995 superspeed switches on-resistance vs. v com_ v com_ (v) r on () maxmax14978 toc02 -0.1 0.1 0.3 0.5 0.7 0.9 1.1 1. 3 1.5 1. 7 1.9 2.1 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 v cc = +3.3v superspeed switches on-resistance vs. v com_ (v cc = +3.3v) v com_ (v) r on () max14978 toc03 -0.1 0.1 0.3 0.5 0.7 0.9 1.1 1. 3 1.5 1. 7 1.9 2.1 0 2 4 6 8 10 12 14 t a = +85c t a = +25c t a = -40c
max14978 superspeed usb passive switch (low/full/hi/superspeed) 9 typical operating characteristics (continued) (v cc = v dd = 3.3v, t a = +25 n c, unless otherwise noted.) 10,000 100,000 0.001 1 0.1 0.01 10 100 1000 low/full/hi-speed switches total harmonic distortion plus noise vs. frequency max14978 toc11 frequency (hz) thd+n (%) r l = 600 -10 1 1,000 100 10 low/full/hi-speed switches frequency response -70 -90 -100 -30 0 -60 -40 -50 -80 -20 max14978 toc10 frequency (mhz) magnitude (db) off-isolation on-loss crosstalk 0 10 20 30 40 50 60 70 80 -40 -15 10 35 60 85 low/full/hi-speed switches com_ leakage current vs. temperature max14978 toc07 temperature (c) leakage current (na) com_ on-leakage com_ off-leakage 0 1 3 2 4 5 low/full/hi-speed switches quiescent supply current vs. logic level max14978 toc08 logic level (v) quiescent supply current (a) 0 1 2 3 0 0.4 0.2 0.8 0.6 1.0 1.2 2.8 3.8 4.8 low/full/hi-speed switches logic-input threshold vs. supply voltage max14978 toc09 supply voltage (v) logic threshold (v) v il v ih superspeed hi-speed switches supply current vs. temperature temperature (c) supply current (a) max14978 toc04 -40 -15 10 35 60 85 0 10 20 30 40 50 60 70 80 v cc = +3.3v superspeed switches logic-input threshold vs. supply voltage supply voltage (v) logic threshold (v) max14978 toc05 1.6 1.8 2.0 2.2 2.4 2.6 2. 8 3.0 3. 2 3.4 3.6 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 v ih v il 0 2 1 4 3 6 5 7 low/full/hi-speed switches on-resistance vs. v com_ max14978 toc06 v com_ (v) r on () 0 1 2 3 t a = -40c t a = +85c t a = +25c
max14978 superspeed usb passive switch (low/full/hi/superspeed) 10 pin configuration pin description top view tqfn 18 19 20 21 v dd gnd v dd gnd 42 + 41 40 39 n.c. n.c. n.c. n.c. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 com0- v dd gnd com1+ com1- gnd com0+ gnd sel2 n.c. comd- n.c. gnd comd+ n.c. n.c. n.c. nc1+ nc1- no0+ no0- no1+ no1- nc0- nc0+ v dd nod- ncd- en v cc sel1 n.c. ncd+ nod+ ep max14978 pin name function 1, 2, 3, 6, 8, 36, 39 - 42 n.c. no connection. not internally connected. 4 comd+ hi-speed usb analog switch, common d+ terminal 5, 10, 14, 17, 19, 21 gnd ground 7 comd- hi-speed usb analog switch, common d- terminal 9 sel2 digital control input for superspeed usb analog switches 11 com0+ superspeed usb analog switch 0, common positive terminal 12 com0- superspeed usb analog switch 0, common negative terminal 13, 18, 20, 30 v dd positive supply voltage input for superspeed usb switches. bypass v dd to gnd with a 0.1 f f ceramic capacitor as close as possible to the device. 15 com1+ superspeed usb analog switch 1, common positive terminal 16 com1- superspeed usb analog switch 1, common negative terminal 22 no1- superspeed usb analog switch 1, normally open negative terminal 23 no1+ superspeed usb analog switch 1, normally open positive terminal 24 no0- superspeed usb analog switch 0, normally open negative terminal 25 no0+ superspeed usb analog switch 0, normally open positive terminal 26 nc1- superspeed usb analog switch 1, normally closed negative terminal 27 nc1+ superspeed usb analog switch 1, normally closed positive terminal 28 nc0- superspeed usb analog switch 0, normally closed negative terminal 29 nc0+ superspeed usb analog switch 0, normally closed positive terminal 31 nod- hi-speed usb analog switch, normally open d- terminal 32 ncd- hi-speed usb analog switch, normally closed d- terminal
max14978 superspeed usb passive switch (low/full/hi/superspeed) 11 pin description (continued) functional diagram/truth table max14978 hi-speed usb analog switches nod+ comd+ ncd+ nod- comd- sel1 en ncd- no1+ com1+ nc1+ no1- com1- sel2 nc1- gnd superspeed usb analog switches no0+ com0+ nc0+ no0- com0- nc0- v cc v dd pin name function 33 en active-low enable input for hi-speed usb switches. drive en high to put hi-speed usb switches in high impedance. drive en low for normal operation. 34 v cc positive-supply voltage input for hi-speed usb switches. bypass v cc to gnd with a 0.1 f f ceramic capacitor as close as possible to the device. 35 sel1 digital control input for hi-speed usb analog switches 37 ncd+ hi-speed usb analog switch, normally closed d+ terminal 38 nod+ hi-speed usb analog switch, normally open d+ terminal ep exposed pad. ep is internally connected to gnd. connect ep to a large ground plane to maximize thermal performance. ep is not intended as an electrical connection point. hi-speed usb switches en sel1 nod_ ncd_ comd_ 0 0 off on 0 1 on off 1 x off off high-z superspeed usb switches sel2 no_ nc_ 0 off on 1 on off
max14978 superspeed usb passive switch (low/full/hi/superspeed) 12 detailed description the max14978 is ideal for superspeed usb and low/ full/hi-speed (1.5/12/480mbps) usb switching applica - tions. the low v ih threshold of the device permits it to be used with logic levels as low as 1.4v. the devices hi-speed usb analog switches are based on a charge- pump-assisted n-channel architecture and operate with 36 f a (typ) quiescent current. the device features dual digital control inputs (sel_) to switch hi-speed usb and superspeed usb signal paths separately. digital control inputs (sel1, sel2) the devices provides dual digital control inputs (sel1, sel2) to select the signal path between the com_ and no_ or nc_ channels. drive sel1 and sel2 rail-to-rail to minimize power consumption. see the functional diagram/truth table . analog-signal levels the devices switches are bidirectional, allowing no_, nc_, and com_ to be configured as either inputs or outputs. the hi-speed usb switches are equipped with a charge- pump-assisted n-channel architecture that allows the switch to pass analog signals that exceed v cc up to the overvoltage fault-protection threshold. this allows usb signals that exceed v cc to pass, allowing compliance with usb requirements for voltage levels. the superspeed usb switches accept signals on the com_, no_, and nc_ channels within a range of -0.1v to (v dd - 1.2v). signals on the com_+ channels are routed to either the no_+ or nc_+ channels, and signals on the com_- channels are routed to either the no_- or nc_- channels. overvoltage fault protection the device features overvoltage fault protection on comd_. fault protection prevents these switches from being damaged due to shorts to the usb vbus voltage rail. fault protection protects the switch and usb trans - ceiver from damaging voltage levels. when voltages on comd_ exceed the fault-protection threshold (v fp ), comd_, ncd_ and nod_ are high impedance. enable input the device features a shutdown mode for the hi-speed usb analog switches that reduces the v cc quiescent current to 0.1 f a (typ) and places comd+ and comd- in high impedance. drive en high to place the hi-speed usb analog switches in shutdown mode, and drive en low for normal operation. applications information usb switching the devices analog switches are fully compliant with the usb 2.0 and usb 3.0 specifications. the low on-resis - tance and low on-capacitance of these switches make them ideal for high-performance switching applications. the device is ideal for routing usb data lines and for applications that require switching between multiple usb hosts or devices. the devices hi-speed usb ana - log switches also feature overvoltage fault protection to guard systems against shorts to the usb vbus voltage rail that is required for all hi-speed usb applications. extended esd protection as with all maxim devices, esd protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. comd+ and comd- are further protected against static electricity. maxims engineers have developed state-of- the-art structures to protect these pins against esd up to q 15kv without damage. the esd structures withstand high esd in normal operation and when the device is powered down. after an esd event, the device continues to function without latchup. the device is characterized for protection to the follow - ing limits: ? q 15kv using human body model ? q 15kv using iec 61000-4-2 air gap discharge method ? q 8kv using iec 61000-4-2 contact discharge method note: high esd performance is only applicable to the hi-speed usb section of the switch. the superspeed usb section is rated to q 6kv hbm.
max14978 superspeed usb passive switch (low/full/hi/superspeed) 13 esd test conditions esd performance depends on a variety of conditions. contact maxim for a reliability report that documents test setup, test methodology, and test results. human body model figure 6a shows the human body model, and figure 6b shows the current waveform it generates when dis - charged into a low-impedance state. this model consists of a 100pf capacitor charged to the esd voltage of inter - est, which is then discharged into the test device through a 1.5k i resistor. iec 61000-4-2 the main difference between tests done using the human body model and iec 61000-4-2 is higher peak current in iec 61000-4-2. because series resistance is lower in the iec 61000-4-2 esd test model (figure 7a) the esd- withstand voltage measured to this standard is generally lower than that measured using the human body model. figure 7b shows the current waveform for the q 8kv iec 61000-4-2 level 4 esd contact discharge test. the air gap discharge test involves approaching the device with a charged probe. the contact discharge method connects the probe to the device before the probe is energized. layout high-speed switches require proper layout and design procedures for optimum performance. keep design- controlled impedance pcb traces as short as pos - sible or follow impedance layouts per the superspeed usb specification. ensure that power-supply bypass capacitors are placed as close as possible to the device. multiple bypass capacitors are recommended. connect all grounds and the exposed pad to large ground planes where possible. figure 6a. human body esd test model figure 6b. human body current waveform figure 7a. iec 61000-4-2 esd test model figure 7b. iec 61000-4-2 esd generator current waveform charge-current- limit resistor discharge resistance storage capacitor c s 100pf r c 1m r d 1500 high- voltage dc source device under test 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 amperes charge-current- limit resistor discharge resistance storage capacitor c s 150pf r c 50m to 100m r d 330 high- voltage dc source device under test 100% 90% 60ns 10% t r = 0.7ns to 1ns i peak i 30ns t
max14978 superspeed usb passive switch (low/full/hi/superspeed) 14 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 cmos devices. always apply v cc and v dd before applying analog signals, especially if the analog signals are not current limited. package information for the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. package type package code outline no. land pattern no. 42 tqfn-ep t423590m+1 21-0181 90-0079
maxim cannot assume responsibility for use of any circuitry other than circuitry entirely 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, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 15 ? 2011 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. max14978 superspeed usb passive switch (low/full/hi/superspeed) revision history revision number revision date description pages changed 0 9/10 initial release 1 4/11 updated analog signal range specification in electrical characteristics 2

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