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general description the max3362 low-power, high-speed transceiver for rs-485/rs-422 communication operates from a single +3.3v power supply. the device contains one differen- tial transceiver consisting of a line driver and receiver. the transceiver operates at data rates up to 20mbps, with an output skew of less than 6ns. driver and receiv- er propagation delays are guaranteed below 50ns. this fast switching and low skew make the max3362 ideal for multidrop clock/data distribution applications. the output level is guaranteed at +1.5v with a standard 54 ? load, compliant with rs-485 specifications. the transceiver draws 1.7ma supply current when unloaded or fully loaded with the drivers disabled. additionally, the max3362 has a low-power shutdown mode, reducing the supply current to 1?. the max3362 has a 1/8-unit-load receiver input imped- ance, allowing up to 256 transceivers on the bus. the max3362 is designed for half-duplex communication. the device has a hot-swap feature that eliminates false transitions on the data cable during circuit initialization. the drivers are short-circuit current limited, and a ther- mal shutdown circuit protects against excessive power dissipation. the max3362 is available in an 8-pin sot package and specified over industrial and automotive tempera- ture ranges. applications clock/data distribution telecom equipment security equipment point-of-sale equipment industrial controls features space-saving 8-pin sot package guaranteed 20mbps data rate operates from a single +3.3v supply 6ns (max) transmitter and receiver skew hot-swap feature interoperable with +5v logic allows up to 256 transceivers on the bus 1a low-power shutdown mode 1.7ma operating supply current -7v to +12v common-mode range current limiting and thermal shutdown half-duplex operation automotive temperature range variants max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package ________________________________________________________________ maxim integrated products 1 ordering information 19-2218; rev 3; 3/07 # indicates an rohs-compliant part. for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. pa rt t em p r a ng e pin- pa ck a g e t o p m a rk pk g c o de m ax3362e ka-t - 40c to + 85c 8 sot23- 8 aajl s 8-1 m ax3362aka-t - 40c to + 125c 8 sot23- 8 aall s 8-1 m ax3362e ka#t - 40c to + 85c 8 sot23- 8#aep h s 8-1 m ax3362aka#t - 40c to + 125c 8 sot23- 8#aep p s 8-1 max3362 di de ro re re d r b a b a a ba b 120 ? 120 ? d r di de ro re d r di de ro d r de di ro re typical operating circuit pin configuration and functional diagram appear at end of data sheet.
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 2 _______________________________________________________________________________________ absolute maximum ratings dc electrical characteristics (v cc = +3.3v ?%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25?.) (notes 1, 2) 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. all voltages with respect to gnd. v cc , re , de, di ......................................................-0.3v to +6v receiver input voltages, driver output voltages (a, b) .......................................................-8v to +13v receiver input current, driver output current (a, b) .................................................................250ma |v a - v b |..................................................................................+8v receiver output voltage (ro)....................-0.3v to (v cc + 0.3v) continuous power dissipation (t a = +70?) 8-pin sot (derate 9.7mw/? above +70?) ............... 777mw operating temperature range max3362e__ .................................................. -40? to +85? max3362a__ ................................................ -40? to +125? storage temperature range .............................-65? to +150? junction temperature ......................................................+150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units driver figure 1, r l = 100 ? (rs-422) (extended temperature range) 2.0 figure 1, r l = 100 ? (automotive temperature range) 1.5 differential driver output v od figure 1, r l = 54 ? (rs-485) (extended temperature range) 1.5 v change in magnitude of differential output voltage ? v od figure 1, r l = 54 ? or 100 ? (note 3) 0.2 v driver common-mode output voltage v oc figure 1, r l = 54 ? or 100 ? 3v change in magnitude of common-mode voltage ? v oc figure 1, r l = 54 ? or 100 ? (note 3) 0.2 v input high voltage v ih de, di, re 2.0 v input low voltage v il de, di, re 0.8 v input hysteresis v hys de, di, re 50 mv input current (de, di, re )i in 0 < v in < 5v 1a 0 < v out < 12v (note 4) +250 driver short-circuit output current i osd -7v < v out < v cc (note 4) -250 ma (v cc - 1v) < v out < 12v (note 4) +25 driver short-circuit foldback output current i osdf -7v < v out < 1v (note 4) -25 ma
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package _______________________________________________________________________________________ 3 dc electrical characteristics (continued) (v cc = +3.3v 5%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) (notes 1, 2) switching characteristics (v cc = +3.3v 5%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) (note 1) parameter symbol conditions min typ max units t pdlh 50 driver propagation delay t pdhl figures 2 and 3, r l = 54 ? , c l = 50pf 50 ns t dr 12.5 driver differential output rise or fall time t df figures 2 and 3, r l = 54 ? , c l = 50pf 12.5 ns driver output skew t dskew figures 2 and 3, r l = 54 ? , c l = 50pf t dskew = |t pdlh - t pdhl | 6ns maximum data rate f max 20 mbps driver enable to output low t pdzl figure 4, r l = 500 ? , c l = 50pf 100 ns driver disable time from low t pdlz figure 4, r l = 500 ? , c l = 50pf 100 ns driver disable time from high t pdhz figure 5, r l = 500 ? , c l = 50pf 100 ns parameter symbol conditions min typ max units thermal shutdown threshold v ts 150 c thermal shutdown hysteresis v tsh 10 c receiver receiver differential threshold voltage v th -7v < v cm < 12v -200 0 +200 mv receiver input hysteresis ? v th v a + v b = 0 25 mv receiver output high voltage v oh i o = -1ma, v a - v b = v th v cc - 0.4 v receiver output low voltage v ol i o = 1ma, v a - v b = -v th 0.4 v three-state output current at receiver i ozr 0 < v o < v cc 1a receiver input resistance r in v cm = 12v 96 k ? v in = +12v 125 receiver input current i in de = gnd, v cc = gnd or 3.465v v in = -7v -100 a receiver output short-circuit current i osr 0 < v ro < v cc 150 ma power supply supply voltage v cc 3.135 3.300 3.465 v supply current in normal operation (static condition) i q no load, di = v cc or gnd 1.7 3 ma supply current in shutdown mode i shdn de = gnd, re = v cc 110a
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 4 _______________________________________________________________________________________ note 1: devices production tested at +25 c. over-temperature limits are guaranteed by design. note 2: all currents into the device are positive; all currents out of the device are negative. all voltages are referenced to device ground, unless otherwise noted. note 3: ? v od and ? v oc are the changes in v od and v oc , respectively, when the di input changes state. note 4: the short-circuit output current applies to peak current just prior to foldback-current limiting; the short-circuit foldback ou t- put current applies during current limiting to allow a recovery from bus contention. note 5: shutdown is enabled by bringing re high and de low. if the enable inputs are in this state for less than 50ns, the device is guaranteed not to enter shutdown. if the enable inputs are in this state for at least 600ns, the device is guaranteed to have entered shutdown. note 6: transition time from shutdown mode to normal operation. switching characteristics (continued) (v cc = +3.3v 5%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) (note 1) parameter symbol conditions min typ max units driver enable to output high t pdzh figure 5, r l = 500 ? , c l = 50pf 100 ns t prlh 50 receiver propagation delay t prhl figure 6, c l = 15pf 50 ns receiver output skew t rskew figure 6, c l = 15pf t rskew = |t prlh - t prhl | 6ns receiver enable to output low t przl figure 7, r l = 1k ? , c l = 15pf 100 ns receiver enable to output high t przh figure 7, r l = 1k ? , c l = 15pf 100 ns receiver disable time from low t prlz figure 7, r l = 1k ? , c l = 15pf 100 ns receiver disable time from high t prhz figure 7, r l = 1k ? , c l = 15pf 100 ns time to shutdown t sd (note 5) 50 600 ns driver enable from output high to shutdown t pdhs 50 600 ns driver enable from output low to shutdown t pdls 50 600 ns receiver enable from output high to shutdown t prhs 50 600 ns receiver enable from output low to shutdown t prls 50 600 ns time to normal operation t no (note 6) 1500 3000 ns driver enable from shutdown to output high t pdsh figure 5 r l = 500 ? , c l = 50pf 1500 3000 ns driver enable from shutdown to output low t pdsl figure 4 r l = 500 ? , c l = 50pf 1500 3000 ns receiver enable from shutdown to output high t prsh figure 7 r l = 1k ? , c l = 15pf 1500 3000 ns receiver enable from shutdown to output low t prsl figure 7 r l = 1k ? , c l = 15pf 1500 3000 ns
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package _______________________________________________________________________________________ 5 typical operating characteristics (v cc = +3.3v, t a = +25 c, unless otherwise noted.) 0 10 5 20 15 35 30 25 40 01.0 0.5 1.5 2.0 2.5 3.0 3.5 output current vs. receiver output low voltage max3362 toc01 receiver output low voltage (v) output current (ma) -30 -20 -25 -10 -15 -5 0 0 1.5 2.0 0.5 1.0 2.5 3.0 3.5 output current vs. receiver output high voltage max3362 toc02 receiver output high voltage (v) output current (ma) 3.22 3.23 3.25 3.24 3.26 -40 -10 5 35 50 -25 65 80 95 110 125 receiver output high voltage vs. temperature max3362 toc03 temperature ( c) receiver output high voltage (v) 20 0 0.01 0.02 0.03 0.04 0.05 -40 -10 5 -25 203550658095110125 receiver output low voltage vs. temperature max3362 toc04 temperature ( c) receiver output low voltage (v) driver output current vs. differential output voltage max3362 toc05 differential output voltage (v) driver output current (ma) 3.2 3.0 2.8 2.6 2.4 15 30 45 60 75 0 2.2 3.4 driver differential output voltage vs. temperature max3362 toc06 temperature ( c) driver differential output voltage (v) 110 95 80 65 50 35 20 5 -10 -25 0.5 1.0 1.5 2.0 2.5 3.0 0 -40 125 r l = 54 ? driver output current vs. driver output low voltage max3362 toc07 driver output low voltage (v) driver output current (ma) 11 10 8 9 2 3 4 5 6 7 1 10 20 30 40 50 60 70 80 90 100 110 120 130 0 012 driver output current vs. driver output high voltage max3362 toc08 driver output high voltage (v) driver output current (ma) 4 3 1 2 -5 -4 -3 -2 -1 0 -6 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 -140 -7 5 supply current vs. temperature max3362 toc09 temperature ( c) i cc (ma) 110 95 -25 -10 5 35 50 65 20 80 1.69 1.70 1.71 1.72 1.73 1.74 1.75 1.76 1.68 -40 125
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 6 _______________________________________________________________________________________ shutdown supply current vs. temperature max3362 toc10 temperature ( c) i shdn ( a) 110 95 80 65 50 35 20 5 -10 -25 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0 -40 125 driver output skew vs. temperature max3362 toc11 temperature ( c) driver output skew (ns) 110 95 65 80 -10 5 20 35 50 -25 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0 -40 125 25 27 29 31 33 35 receiver propagation delay vs. temperature max3362 toc12 receiver propagation delay (ns) -40 -10 5 35 50 -25 65 80 95 110 125 temperature ( c) 20 20ns/div unloaded driver output waveform max3362 toc13 b 3.3v f din = 16mbps a 0 20ns/div loaded driver output waveform max3362 toc14 b 2v f din = 16mbps r l = 54 ? a 0 20ns/div driver propagation delay max3362 toc15 a 0 f din = 16mbps din 2v/div b 3.3v 20ns/div receiver propagation delay max3362 toc16 ro f din = 16mbps a 2v/div 2v/div b typical operating characteristics (continued) (v cc = +3.3v, t a = +25 c, unless otherwise noted.)
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package _______________________________________________________________________________________ 7 pin description pin name description 1ro receiver output. ro is high if the receiver input differential (a-b) 200mv and the receiver is enabled ( re is low). ro is low if the receiver input differential (a-b) -200mv and the receiver is enabled. 2 re receiver output enable. driving re low enables ro. ro is high impedance when re is high. drive re high and de low (disable both receiver and driver outputs) to enter low-power shutdown mode. 3de driver output enable. driving de high enables driver outputs. these outputs are high impedance when de is low. drive re high and de low (disable both receiver and driver outputs) to enter low- power shutdown mode. 4di d r i ver inp ut. d r i vi ng d i l ow for ces the noni nver ti ng outp ut l ow and i nver ti ng outp ut hi g h, w hen the d r i ver i s enab l ed ( d e i s hi g h) . d r i vi ng d i hi g h for ces the noni nver ti ng outp ut hi g h and i nver ti ng outp ut l ow . 5 gnd ground 6 a noninverting receiver input and noninverting driver output 7 b inverting receiver input and inverting driver output 8v cc supply voltage. v cc = 3.3v 5%. bypass v cc to gnd with a 0.1f capacitor. out v cc r l c l d c l = 50pf r l = 54 ? figure 2. driver timing test circuit 0 v cc /2 v cc b a t pdlh (a+b)/2 a - b 10% 90% t pdhl t ri t fi t ri = 5ns t fi = 5ns t df t dr di figure 3. driver propagation delay v od v cc r l /2 r l /2 v oc d figure 1. driver dc test load in out t pdsl , t pdzl t pdlz 0.25v v ol 0 v cc /2 v om = (v ol + v cc ) /2 v cc v cc v cc r l = 500 ? c l = 50pf generator 50 ? 0 or 3v out s1 d figure 4. driver enable and disable times (t pdsl , t pdzl , t pdls , t pdlz )
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 8 _______________________________________________________________________________________ in out t pdsh , t pdzh t pdhz 0.25v v ol 0 v cc /2 v om = (v oh ) /2 v cc v cc r l = 500 ? c l = 50pf generator 50 ? 0 or 3v out s1 d figure 5. driver enable and disable times (t pdsh , t pdzh , t pdhs , t pdhz ) in 1.5v 1.5v 1.5v 0 2 out t prlh t prhl 3.0v v ol v id 0 0 v om v om v om = v cc v cc c l = 15pf generator 50 ? out r figure 6. receiver propagation delays
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package _______________________________________________________________________________________ 9 detailed description the max3362 low-power, high-speed transceiver for rs-485/rs-422 communication operates from a single +3.3v power supply. the device contains one differen- tial line driver and one differential line receiver. the dri- ver and receiver may be independently enabled. when disabled, outputs enter a high-impedance state. the transceiver guarantees data rates up to 20mbps, with an output skew of less than 6ns. this low skew time makes the max3362 ideal for multidrop clock/data distribution applications, such as cellular base stations. driver and receiver propagation delays are below 50ns. the output level is guaranteed at 1.5v on a standard 54 ? load. the device has a hot-swap feature that eliminates false transitions on the data cable during circuit initialization. also, drivers are short-circuit current limited and are protected against excessive power dissipation by ther- mal shutdown circuitry. 1.5v -1.5v v id v cc c l generator 50 ? r l = 1k ? r s3 s1 s2 in out 3v 0 v oh v oh 0 1.5v t przh t prsh in out 3v 0 0 1.5v t prhz 0.25v in out 3v 0 v oc v ol 1.5v t przl t prsl in out 3v 0 v oh 0 1.5v t prlz 0.25v 1.5v s1 open s2 closed s3 = 1.5v s1 open s2 closed s3 = 1.5v s1 closed s2 open s3 = -1.5v s1 closed s2 open s3 = -1.5v figure 7. receiver enable and disable times
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 10 ______________________________________________________________________________________ the max3362 has a 1/8-unit-load receiver input imped- ance, allowing up to 256 transceivers to be connected simultaneously on a bus. the max3362 is designed for half-duplex communication. driver the driver transfers single-ended input (di) to differen- tial outputs (a, b). the driver enable (de) input controls the driver. when de is high, driver outputs are enabled. these outputs are high impedance when de is low. when the driver is enabled, setting di low forces the noninverting output (a) low and inverting output (b) high. conversely, drive di high to force noninverting output high and inverting output low (table 1). drive re high and de low (disable both receiver and driver outputs) to enter low-power shutdown mode. receiver the receiver reads differential inputs from the bus lines (a, b) and transfers this data as a single-ended output (ro). the receiver enable ( re ) input controls the receiver. drive re low to enable the receiver. driving re high places ro into a high-impedance state. when the receiver is enabled, ro is high if (a-b) 200mv. ro is low if (a-b) -200mv. drive re high and de low (disable both receiver and driver outputs) to enter low-power shutdown mode. hot-swap capability hot-swap input when circuit boards are inserted into a hot or powered backplane, disturbances to the enable and differential receiver inputs can lead to data errors. upon initial cir- cuit board insertion, the processor undergoes its power-up sequence. during this period, the output dri- vers are high impedance and are unable to drive the de input of the max3362 to a defined logic level. leakage currents up to 10a from the high-impedance output could cause de to drift to an incorrect logic state. additionally, parasitic circuit board capacitance could cause coupling of v cc or gnd to de. these fac- tors could improperly enable the driver. when v cc rises, an internal pulldown circuit holds de low for at least 10s and until the current into de exceeds 200a. after the initial power-up sequence, the pulldown circuit becomes transparent, resetting the hot-swap tolerable input. hot-swap input circuitry the max3362 enable inputs feature hot-swap capability. at the input there are two nmos devices, m1 and m2 (figure 8). when v cc ramps from 0, an internal 10s timer turns on m2 and sets the sr latch, which also turns on m1. transistors m2, a 300a current sink, and m1, a 30a current sink, pull de to gnd through an 8k ? resis- tor. m2 is designed to pull de to the disabled state against an external parasitic capacitance up to 100pf that may drive de high. after 10s, the timer deactivates m2 while m1 remains on, holding de low against three- state leakages that may drive de high. m1 remains on until an external source overcomes the required input current. at this time, the sr latch resets and m1 turns off. when m1 turns off, de reverts to a standard, high- impedance cmos input. whenever v cc drops below 1v, the hot-swap input is reset. for re there is a complimentary circuit employing two pmos devices pulling re to v cc . hot-swap line transient the circuit of figure 9 shows a typical offset termination used to guarantee a greater than 200mv offset when a line is not driven (the 50pf represents the minimum parasitic capacitance that would exist in a typical appli- cation). during a hot-swap event when the driver is transmitting inputs outputs re de di a b x11 1 0 x10 0 1 0 0 x high z high z 1 0 x shutdown table 1. transmitter functional table receiving inputs output re de a bro 0x 200mv 1 0x -200mv 0 1 1 x high-z 1 0 x shutdown table 2. receiver functional table
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package ______________________________________________________________________________________ 11 v cc timer timer de de (hot swap) 10 s 30 a m1 m2 8k ? 300 a figure 8. simplified structure of the driver enable input (de) t in 3.3v v cc 0.1k ? 1k ? 1k ? v cc or gnd y z 50pf figure 9. differential power-up glitch (hot swap) 10 s/div b v cc 10mv/div 3.3v a a-b 10mv/div ac-coupled 10mv/div ac-coupled 0 figure 10. differential power-up glitch (0.1v/?)
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 12 ______________________________________________________________________________________ connected to the line and is powered up the driver must not cause the differential signal to drop below 200mv. figures 10, 11, and 12 show the results of the max3362 during power-up for three different v cc ramp rates (0.1v/s, 1v/s, and 10v/s). the photos show the v cc ramp, the single-ended signal on each side of the 100 ? termination, as well as the differential signal across the termination. low-power shutdown mode low-power shutdown mode is initiated by bringing both re high and de low. in shutdown, the max3362 typi- cally draws only 1a supply current. re and de may be driven simultaneously; the device is guaranteed not to enter shutdown if re is high and de is low for less than 50ns. if the inputs are in this state for at least 600ns, the device will enter shutdown. enable times t pdzh, t pdzl, t przh and t przl in the switching characteristics table assume the device was not in a low-power shutdown state. enable times t pdsh, t pdsl, t prsh, and t prsl assume the device was shut down. drivers and receivers take longer to become enabled from low-power shutdown mode than from driver/receiver disable mode. applications information propagation delays figures 5 and 6 show the typical propagation delays. skew time is simply the difference between the low-to- high and high-to-low propagation delay. small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle). both the receiver skew time and driver skew time are under 6ns. 256 transceivers on the bus the standard rs-485 receiver input impedance is 12k ? (one-unit load), and a standard driver can drive up to 32 unit loads. the max3362 transceiver has a 1/8-unit- load receiver input impedance (96k ? ), allowing up to 256 transceivers to be connected in parallel on one communication line. any combination of these devices and/or other rs-485 transceivers with a total of 32 unit loads or less can be connected to the line. driver output protection two mechanisms prevent excessive output current and power dissipation caused by faults or by bus con- tention. the first, a foldback current limit on the output stage, provides immediate protection against short cir- cuits over the whole common-mode voltage range (see typical operating characteristics ). the second, a ther- mal shutdown circuit, forces the driver outputs into a high-impedance state if the die temperature becomes excessive. typical applications the max3362 transceiver is designed for bidirectional data communications on multipoint bus transmission lines. the typical operating circuit shows a typical net- work applications circuit. to minimize reflections, the line should be terminated at both ends in its character- istic impedance, and stub lengths off the main line should be kept as short as possible. 1 s/div b v cc 10mv/div 3.3v a a-b 10mv/div ac-coupled 10mv/div ac-coupled 0 figure 11. differential power-up glitch (1v/?) 200ns/div b v cc 10mv/div 3.3v a a-b 50mv/div ac-coupled 50mv/div ac-coupled 0 figure 12. differential power-up glitch (10v/?)
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package ______________________________________________________________________________________ 13 a gnd di 1 2 8 7 v cc b re de ro sot23 top view 3 4 6 5 max3362 pin configuration rd di v cc re b a gnd de r d max3362 functional diagram chip information process: bicmos
max3362 3.3v, high-speed, rs-485/rs-422 transceiver in sot package 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. 14 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2007 maxim integrated products is a registered trademark of maxim integrated products, inc. sot23, 8l .eps package information (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .) revision history pages changed at rev 3: 1, 13, 14

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