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_______________general description the max3483, max3485, max3486, max3488, max3490, and MAX3491 are 3.3v, low-power trans- ceivers for rs-485 and rs-422 communication. each part contains one driver and one receiver. the max3483 and max3488 feature slew-rate-limited dri- vers that minimize emi and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250kbps. the par- tially slew-rate-limited max3486 transmits up to 2.5mbps. the max3485, max3490, and MAX3491 transmit at up to 10mbps. drivers are short-circuit current limited and are protect- ed against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. the receiver input has a fail-safe feature that guarantees a logic-high output if both inputs are open circuit. the max3488, max3490, and MAX3491 feature full- duplex communication, while the max3483, max3485, and max3486 are designed for half-duplex communi- cation. ________________________applications low-power rs-485/rs-422 transceivers telecommunications transceivers for emi-sensitive applications industrial-control local area networks ____________________________features ? operate from a single 3.3v supply no charge pump! ? interoperable with +5v logic ? 8ns max skew (max3485/max3490/MAX3491) ? slew-rate limited for errorless data transmission (max3483/max3488) ? 2na low-current shutdown mode (max3483/max3485/max3486/MAX3491) ? -7v to +12v common-mode input voltage range ? allows up to 32 transceivers on the bus ? full-duplex and half-duplex versions available ? industry standard 75176 pinout (max3483/max3485/max3486) ? current-limiting and thermal shutdown for driver overload protection ______________ordering information ordering information continued at end of data sheet. * contact factory for for dice specifications. max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers ________________________________________________________________ maxim integrated products 1 call toll free 1-800-998-8800 for free samples or literature. 19-0333; rev 0; 12/94 part max3483 cpa max3483csa max3483c/d 0? to +70? 0? to +70? 0? to +70? temp. range pin-package 8 plastic dip 8 so dice* part number guaranteed data rate (mbps) supply voltage (v) half/full duplex slew-rate limited driver/ receiver enable shutdown current (na) pin count max3483 0.25 half yes yes 2 8 max3485 10 half no yes 2 8 max3486 2.5 half yes yes 2 8 max3488 0.25 full yes no 8 max3490 10 full no no 8 MAX3491 10 3.0 to 3.6 full no yes 2 14 ______________________________________________________________selection table max3483epa max3483esa -40? to +85? -40? to +85? 8 plastic dip 8 so max3485 cpa max3485csa max3485c/d 0? to +70? 0? to +70? 0? to +70? 8 plastic dip 8 so dice* max3485epa max3485esa -40? to +85? -40? to +85? 8 plastic dip 8 so
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 2 _______________________________________________________________________________________ absolute maximum ratings dc electrical characteristics (v cc = 3.3v ?.3v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?) stresses beyond those listed under ?bsolute 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. supply voltage (v cc ) ...............................................................7v control input voltage (re , de) ...................................-0.3v to 7v driver input voltage (di) .............................................-0.3v to 7v driver output voltage (a, b, y, z)..........................-7.5v to 12.5v receiver input voltage (a, b) ................................-7.5v to 12.5v receiver output voltage (ro)....................-0.3v to (v cc + 0.3v) continuous power dissipation (t a = +70?) 8-pin plastic dip (derate 9.09mw/? above +70?) .....727mw 8-pin so (derate 5.88mw/? above +70?)..................471mw 14-pin plastic dip (derate 10mw/? above +70?) ......800mw 14-pin so (derate 8.33mw/? above +70?)................667mw operating temperature ranges max34_ _c_ _.......................................................0? to +70? max34_ _e_ _ ....................................................-40? to +85? storage temperature range .............................-65? to +160? lead temperature (soldering, 10sec) .............................+300? de = 0v, v cc = 0v or 3.6v de = 0v, re = v cc , v cc = 0v or 3.6v, MAX3491 de = 0v, re = 0v, v cc = 0v or 3.6v, MAX3491 k 12 r in receiver input resistance ? ? i ozr three-state (high impedance) output current at receiver v 0.4 v ol receiver output low voltage v v cc - 0.4 v oh receiver output high voltage mv 50 ? v th receiver input hysteresis v -0.2 0.2 v th receiver differential threshold voltage ? -1 i o output leakage (y, z) in shutdown mode 1 ? -20 i o output leakage (y, z) v 0.2 ? v od change in magnitude of driver differential output voltage for complementary output states (note 1) v 1.5 v od 2.0 differential driver output 20 ma -0.8 i in2 input current (a, b) 1.0 ? ? i in1 logic input current v 3 v oc driver common-mode output voltage v 0.2 ? v oc change in magnitude of common-mode output voltage (note 1) v 2.0 v ih input high voltage v 0.8 v il input low voltage units min typ max symbol parameter r l = 54 or 100 , figure 4 -7v v cm 12v r l = 54 (rs-485), figure 4 v cc = 3.6v, 0v v out v cc r l = 100 (rs-422), figure 4 i out = 2.5ma, v id = 200mv, figure 6 i out = -1.5ma, v id = 200mv, figure 6 v cm = 0v v out = 12v v in = -7v -7v v cm 12v v out = -7v v in = 12v de, di, re r l = 54 or 100 , figure 4 r l = 54 or 100 , figure 4 de, di, re v out = 12v de, di, re v out = -7v conditions r l = 60 (rs-485), v cc = 3.3v, figure 5 1.5
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers _______________________________________________________________________________________ 3 no load, di = 0v or v cc ? 0.002 1 i shdn supply current in shutdown mode 0.95 1.9 ma 1.1 2.2 i cc supply current ma -250 i osd 250 driver short-circuit output current ma ? ?0 i osr receiver short-circuit output current units min typ max symbol parameter de = 0v, re = v cc , di = v cc or 0v de = 0v, re = 0v de = v cc , re = 0v or v cc v out = -7v v out = 12v 0v v ro v cc conditions dc electrical characteristics (continued) (v cc = 3.3v ?.3v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?) ns 72235 t plh driver propagation delay, low-to-high level ns 3825 t td ns 12235 t dd driver differential output delay driver differential output transition time ns 650 900 t psh driver output enable time from shutdown to high level ns 650 900 t psl driver output enable time from shutdown to low level ns 40 80 t phz driver output disable time from high level ns 72235 t phl driver propagation delay, high-to-low level ns 8 t pds | t plh - t phl | driver propagation delay skew (note 2) ns 45 90 t pzl driver output enable time to low level ns 45 90 t pzh driver output enable time to high level units min typ max symbol parameter r l = 27 , figure 8 r l = 60 , figure 7 r l = 60 , figure 7 r l = 110 , figure 9 r l = 110 , figure 10 r l = 110 , figure 9 r l = 27 , figure 8 r l = 27 , figure 8 r l = 110 , figure 10 r l = 110 , figure 9 conditions driver switching characteristics?ax3485, max3490, and MAX3491 (v cc = 3.3v, t a = +25?) ns 40 80 t plz driver output disable time from low level r l = 110 , figure 10 driver switching characteristics?ax3486 (v cc = 3.3v, t a = +25?) ns 45 80 t plz driver output disable time from low level r l = 110 , figure 10 ns 20 48 70 t plh driver propagation delay, low-to-high level ns 15 35 60 t td ns 24 48 70 t dd driver differential output delay driver differential output transition time ns 700 1000 t psh driver output enable time from shutdown to high level ns 700 1000 t psl driver output enable time from shutdown to low level ns 45 80 t phz driver output disable time from high level ns 20 48 70 t phl driver propagation delay, high-to-low level ns 11 t pds | t plh - t phl | driver propagation delay skew (note 2) ns 55 100 t pzl driver output enable time to low level ns 55 100 t pzh driver output enable time to high level units min typ max symbol parameter r l = 27 , figure 8 r l = 60 , figure 7 r l = 60 , figure 7 r l = 110 , figure 9 r l = 110 , figure 10 r l = 110 , figure 9 r l = 27 , figure 8 r l = 27 , figure 8 r l = 110 , figure 10 r l = 110 , figure 9 conditions driver output enable/disable times (max3485/MAX3491 only)
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 4 _______________________________________________________________________________________ driver switching characteristics?ax3483 and max3488 (v cc = 3.3v, t a = +25?) ns 50 80 t plz driver output disable time from low level r l = 110 , figure 10 ns 700 1000 1500 t plh driver propagation delay, low-to-high level ns 400 700 1200 t td ns 600 900 1400 t dd driver differential output delay driver differential output transition time ? 2.2 3.0 t psh driver output enable time from shutdown to high level ? 1.9 2.7 t psl driver output enable time from shutdown to low level ns 50 80 t phz driver output disable time from high level ns 700 1000 1500 t phl driver propagation delay, high-to-low level ns 100 t pds | t plh - t phl | driver propagation delay skew (note 2) ns 900 1300 t pzl driver output enable time to low level ns 600 800 t pzh driver output enable time to high level units min typ max symbol parameter r l = 27 , figure 8 r l = 60 , figure 7 r l = 60 , figure 7 r l = 110 , figure 9 r l = 110 , figure 10 r l = 110 , figure 9 r l = 27 , figure 8 r l = 27 , figure 8 r l = 110 , figure 10 r l = 110 , figure 9 conditions receiver switching characteristics (v cc = 3.3v, t a = +25?) ns 25 45 t prlz receiver output disable time from low level c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only ns 25 65 90 ns 80 190 300 t shdn time to shutdown ns 720 1400 t prsh receiver output enable time from shutdown to high level ns 720 1400 t prsl receiver output enable time from shutdown to low level ns 25 45 t prhz receiver output disable time from high level ns 25 65 90 ns 10 ns 25 50 t przl receiver output enable time to low level ns 25 50 t przh receiver output enable time to high level units min typ max symbol parameter v id = 0v to 3.0v, c l = 15pf, figure 11 max3483/max3485/max3486/MAX3491 only (note 3) c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only v id = 0v to 3.0v, c l = 15pf, figure 11 v id = 0v to 3.0v, c l = 15pf, figure 11 c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only c l = 15pf, figure 12, max3483/max3485/max3486/MAX3491 only conditions 25 75 120 t rplh receiver propagation delay, low-to-high level max3483/max3488 25 75 120 t rphl receiver propagation delay, high-to-low level max3483/max3488 20 t rpds | t plh - t phl | receiver propagation delay skew max3483/max3488 note 1: ? v od and ? v oc are the changes in v od and v oc , respectively, when the di input changes state. note 2: measured on | t plh (y) - t phl (y) | and | t plh (z) - t phl (z) |. note 3: the transceivers are put into shutdown by bringing re high and de low. if the inputs are in this state for less than 80ns, the parts are guaranteed not to enter shutdown. if the inputs are in this state for at least 300ns, the parts are guaranteed to have entered shutdown. see low-power shutdown mode section. driver output enable/disable times (max3483 only)
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers _______________________________________________________________________________________ 5 __________________________________________typical operating characteristics (v cc = 3.3v, t a = +25?, unless otherwise noted.) 25 20 15 10 5 0 0 0.5 1.0 1.5 2.0 2.5 3.5 3.0 output current vs. receiver output low voltage max3483-01 output low voltage (v) output current (ma) -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 0 0.5 1.0 1.5 2.0 2.5 3.5 3.0 output current vs. receiver output high voltage max3483-02 output high voltage (v) output current (ma) 3.00 3.05 3.10 3.15 3.20 3.25 3.30 -40 -20 0 20 40 60 100 80 receiver output high voltage vs. temperature max3483-03 temperature (?) output high voltage (v) i ro = 1.5ma 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 -40 -20 0 20 40 60 100 80 receiver output low voltage vs. temperature max3483-04 temperature (?) output low voltage (v) i ro = 2.5ma 25 0 50 75 100 125 150 175 0246 81012 output current vs. driver output low voltage max3483-07 output low voltage (v) output current (ma) 100 90 80 70 60 50 40 30 20 10 0 0 0.5 1.0 1.5 2.0 2.5 3.5 3.0 driver output current vs. differential output voltage max3483-05 differential output voltage (v) output current (ma) 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.6 2.5 -40 -20 0 20 40 60 100 80 driver differential output voltage vs.temperature max3483-06 temperature (?) differential output voltage (v) r = 54 w 0 -100 -80 -60 -40 -20 5 4 3 2 1 0 -7 -6 -3 -4 -5 -2 -1 output current vs. driver output high voltage max3483-08 output high voltage (v) output current (ma)
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 6 _______________________________________________________________________________________ 0.8 0.7 0.9 1.0 1.1 1.2 -40 -20 0 20 40 60 100 80 supply current vs. temperature max3483-09 temperature (?) supply current (ma) x = don? care de = v cc , re = x de = 0, re = 0 _____________________________typical operating characteristics (continued) 0 10 20 30 40 50 60 70 80 100 90 -40 -20 0 20 40 60 100 80 shutdown current vs. temperature max3483-10 temperature (?) shutdown current (na) ______________________________________________________________pin description 3 4 5 6 8 7 1 max3483/ max3485/ max3486 2 1 2 3 4 5 6 7 8 2 receiver output. if a > b by 200mv, ro will be high; if a < b by 200mv, ro will be low. 3 receiver output enable. ro is enabled when re is low; ro is high imped- ance when re is high. if re is high and de is low, the device will enter a low-power shutdown mode. 4 driver output enable. the driver outputs are enabled by bringing de high. they are high impedance when de is low. if re is high and de is low, the device will enter a low-power shutdown mode. if the driver outputs are enabled, the parts function as line drivers. while they are high impedance, they function as line receivers if re is low. 5 driver input. a low on di forces output y low and output z high. similarly, a high on di forces output y high and output z low. 6, 7 ground 9 noninverting driver output 10 inverting driver output noninverting receiver input and noninverting driver output 12 noninverting receiver input ro re de di gnd y z a a b inverting receiver input and inverting driver output 11 b inverting receiver input 13, 14 v cc positive supply: 3.0v v cc 3.6v 1, 8 n.c. no connect?ot internally connected max3488/ max3490 pin function MAX3491 function name name
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers _______________________________________________________________________________________ 7 max3483 max3485 max3486 top view note: pin labels y and z on timing, test, and waveform diagrams refer to pins a and b when de is high. 1 2 3 4 8 5 v cc gnd di de re ro r d rt rt 7 6 d r de re di ro a b 1 2 3 4 8 7 6 5 v cc b a gnd di de re ro dip/so r d b a max3488 max3490 top view 1 2 3 4 ro di gnd 8 7 6 5 a b z y v cc dip/so r d rt rt v cc 5 6 7 8 ro di gnd 4 gnd di ro 3 2 a b y z v cc dr r d 1 MAX3491 dip/so top view rt rt de v cc re gnd v cc re gnd de ro di 9 10 12 11 b a z y 5 ro n.c. di 2 1, 8 3 6, 7 13, 14 4 1 2 3 4 5 6 7 14 13 12 11 10 9 8 v cc v cc n.c. a b z y n.c. ro re de di gnd gnd r d d rd r figure 2. max3488/max3490 pin configuration and typical operating circuit figure 3. MAX3491 pin configuration and typical operating circuit figure 1. max3483/max3485/max3486 pin configuration and typical operating circuit
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 8 _______________________________________________________________________________________ v cc d v od v oc 2 r l 2 r l r 0v v oh i oh (-) i ol (+) v ol v id v cc d v od r l v cm = -7v to +12v 375 w 375 w v cc 50 w r l = 60 w c l = 15pf (note 5) generator (note 4) d out c l c l t do t td 50% 1.5v 10% out in 90% 50% 1.5v 10% 90% 3v 0v ? 2.0v ? -2.0v t do t td figure 4. driver v od and v oc figure 7. driver differential output delay and transition times figure 6. receiver v oh and v ol figure 5. driver v od with varying common-mode voltage
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers _______________________________________________________________________________________ 9 v cc v om 3v 0v v oh v om v om v om v om v ol v oh v ol 50 w r l = 27 w c l = 15pf (note 5) generator (note 4) d t plh 1.5v y out z out out s1 in 1.5v ? 1.5v t phl t phl t plh v oh + v ol 2 v om = 3v 0v v oh v om 0v r l = 110 w c l = 50pf (note 5) d 0v or 3v 50 w generator (note 4) t pzh 1.5v 0.25v out out s1 in 1.5v ? 1.5v t phz v oh + v ol 2 v om = v cc r l = 110 w c l = 50pf (note 5) d 50 w generator (note 4) out s1 3v 0v v cc v ol v om t psl 1.5v 0.25v out in 1.5v t plz 0v or 3v figure 8. driver propagation times figure 9. driver enable and disable times (t pzh , t psh , t phz ) figure 10. driver enable and disable times (t pzl , t psl , t plz )
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 10 ______________________________________________________________________________________ v id 50 w c l = 15pf (note 5) generator (note 4) r out t rplh 1.5v out 1.5v 0v in 1.5v 3.0v 0v t rphl v cc v om v om 0v v cc 2 v om = 3v 0v v cc v ol c l (note 5) r 1.5v -1.5v 50 w generator (note 4) v cc v id 1.5v out s1 s2 1k in 1.5v s1 closed s2 open s3 = -1.5v t przl t prsl 3v 0v v oh 0v 1.5v out in 1.5v s1 open s2 closed s3 = 1.5v t przh t prsh 3v 0v v cc v ol 0.25v out in 1.5v s1 closed s2 open s3 = -1.5v t prlz 3v 0v v oh 0v 0.25v 1.5v out in s1 open s2 closed s3 = 1.5v t prhz s3 figure 11. receiver propagation delay figure 12. receiver enable and disable times note 4: the input pulse is supplied by a generator with the following characteristics: prr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 . note 5: c l includes probe and stray capacitance.
____________________function tables devices with receiver/driver enable (max3483/max3485/max3486/MAX3491) table 1. transmitting * b and a outputs are z and y, respectively, for full-duplex part (MAX3491). x = don? care; high-z = high impedance table 2. receiving * de is a ?on? care?(x) for the full-duplex part (MAX3491). x = don? care; high-z = high impedance devices without receiver/driver enable (max3488/max3490) table 3. transmitting table 4. receiving __________applications information the max3483/max3485/max3486/max3488/max3490/ MAX3491 are low-power transceivers for rs-485 and rs-422 communications. the max3483 and max3488 can transmit and receive at data rates up to 250kbps, the max3486 at up to 2.5mbps, and the max3485/ max3490/MAX3491 at up to 10mbps. the max3488/ max3490/MAX3491 are full-duplex transceivers, while the max3483/max3485/max3486 are half-duplex. driver enable (de) and receiver enable (re ) pins are included on the max3483/max3485/max3486/ MAX3491. when disabled, the driver and receiver out- puts are high impedance. reduced emi and reflections (max3483/max3486/max3488) the max3483/max3488 are slew-rate limited, minimiz- ing emi and reducing reflections caused by improperly terminated cables. figure 13 shows both the driver output waveform of a max3485/max3490/MAX3491 transmitting a 125khz signal and the fourier analysis of that waveform. high-frequency harmonics with large amplitudes are evident. figure 14 shows the same infor- mation, but for the slew-rate-limited max3483/max3488 transmitting the same signal. the high-frequency har- monics have much lower amplitudes, and the potential for emi is significantly reduced. low-power shutdown mode (max3483/max3485/max3486/MAX3491) a low-power shutdown mode is initiated by bringing both re high and de low. the devices will not shut down unless both the driver and receiver are disabled (high impedance). in shutdown, the devices typically draw only 2na of supply current. for these devices, the t psh and t psl enable times assume the part was in the low-power shutdown mode; the t pzh and t pzl enable times assume the receiver or driver was disabled, but the part was not shut down. max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers ______________________________________________________________________________________ 11 inputs outputs re de di b* a* mode x 1 1 0 1 normal x 1 0 1 0 normal 0 0 x high-z high-z normal 1 0 x high-z high-z shutdown inputs re de a, b ro mode 0 0* 3 +0.2v 1 normal 0 0* -0.2v 0 normal 0 0* inputs open 1 normal 1 0 x high-z shutdown outputs inputs output a, b ro 3 +0.2v 1 -0.2v 0 inputs open 1 input outputs di z y 1 0 1 0 1 0 5mhz 500khz/div 0hz 10db/div 5mhz 500khz/div 0hz 10db/div figure 13. driver output waveform and fft plot of max3485/ max3490/MAX3491 transmitting a 125khz signal figure 14. driver output waveform and fft plot of max3483/ max3488 transmitting a 125khz signal
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 12 ______________________________________________________________________________________ b 1v/div a 1v/div ro 2v/div 20ns/div di 5v/div v y - v z 2v/div ro 5v/div 2 m s/div b 1v/div a 1v/div ro 2v/div 1 m s/div di 2v/div 20ns/div z 1v/div y 1v/div di 2v/div z 1v/div y 1v/div 1 m s/div di 5v/div v y - v z 2v/div ro 5v/div 2 m s/div figure 15. max3485/max3490/MAX3491 driver propagation delay figure 17. max3483/max3488 driver propagation delay figure 16. max3485/max3490/MAX3491 receiver propagation delay driven by external rs-485 device figure 18. max3483/max3488 receiver propagation delay figure 19. max3483/max3488 system differential voltage at 125khz driving 4000 ft of cable figure 20. max3485/max3490/MAX3491 system differential voltage at 125khz driving 4000 ft of cable
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers ______________________________________________________________________________________ 13 driver output protection excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. a foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see typical operating characteristics ). in addition, a thermal shut- down circuit forces the driver outputs into a high-imped- ance state if the die temperature rises excessively. propagation delay figures 15?8 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). the receiver skew time, | t prlh - t prhl | , is under 10ns (20ns for the max3483/max3488). the driver skew times are 8ns for the max3485/max3490/MAX3491, 11ns for the max3486, and typically under 100ns for the max3483/max3488. line length vs. data rate the rs-485/rs-422 standard covers line lengths up to 4000 feet. for line lengths greater than 4000 feet, see figure 23. figures 19 and 20 show the system differential voltage for parts driving 4000 feet of 26awg twisted-pair wire at 125khz into 120 loads. typical applications the max3483, max3485, max3486, max3488, max3490, and MAX3491 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. figures 21 and 22 show typical net- work applications circuits. these parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in figure 23. to minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. the slew-rate-limited max3483/max3488 and the partially slew-rate-limited max3486 are more tolerant of imperfect termination. di ro de re a b re re re ro ro ro di di di de de de d d d r r r b b b a a a 120 w 120 w d r max3483 max3485 max3486 figure 21. max3483/max3485/max3486 typical rs-485 network
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 14 ______________________________________________________________________________________ 120 w 120 w r d ro re de di a b y 120 w 120 w di di di ro ro ro de de de re re re z z z z y y y aa a bb b d d d r r r max3488 max3490 MAX3491 note: re and de on MAX3491 only. 120 w 120 w data in data out r d ro re de di a b z y max3488 max3490 MAX3491 note: re and de on MAX3491 only. figure 22. max3488/max3490/MAX3491 full-duplex rs-485 network figure 23. line repeater for max3488/max3490/MAX3491
max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers ______________________________________________________________________________________ 15 transistor count: 810 substrate connected to ground __________________ chip topography _ordering information (continued) part max3486 cpa max3486csa max3486c/d 0? to +70? 0? to +70? 0? to +70? temp. range pin-package 8 plastic dip 8 so dice* max3486epa max3486esa -40? to +85? -40? to +85? 8 plastic dip 8 so max3488 cpa max3488csa max3488c/d 0? to +70? 0? to +70? 0? to +70? 8 plastic dip 8 so dice* max3488epa max3488esa -40? to +85? -40? to +85? 8 plastic dip 8 so max3490 cpa max3490csa max3490c/d 0? to +70? 0? to +70? 0? to +70? 8 plastic dip 8 so dice* max3490epa max3490esa -40? to +85? -40? to +85? 8 plastic dip 8 so MAX3491 cpd MAX3491csd MAX3491c/d 0? to +70? 0? to +70? 0? to +70? 14 plastic dip 14 so dice* MAX3491epd MAX3491esd -40? to +85? -40? to +85? 14 plastic dip 14 so * contact factory for for dice specifications. 0.146" (3.71mm) 0.086" (2.18mm) z/b b a y/a gnd di de re ro v cc gnd
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. 16 __________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 (408) 737-7600 1994 maxim integrated products printed usa is a registered trademark of maxim integrated products. max3483/max3485/max3486/max3488/max3490/MAX3491 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceivers 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. 16 __________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 (408) 737-7600 1994 maxim integrated products printed usa is a registered trademark of maxim integrated products. 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. 16 __________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 (408) 737-7600 1994 maxim integrated products printed usa is a registered trademark of maxim integrated products. dim a a1 b c e e h l min 0.053 0.004 0.014 0.007 0.150 0.228 0.016 max 0.069 0.010 0.019 0.010 0.157 0.244 0.050 min 1.35 0.10 0.35 0.19 3.80 5.80 0.40 max 1.75 0.25 0.49 0.25 4.00 6.20 1.27 inches millimeters 21-0041a so small outline package (0.150 in.) dim d d d min 0.189 0.337 0.386 max 0.197 0.344 0.394 min 4.80 8.55 9.80 max 5.00 8.75 10.00 inches millimeters pins 8 14 16 1.27 0.050 l 0?8 h e d e a a1 c 0.101mm 0.004in. b dim a a1 a2 a3 b b1 c d1 e e1 e ea eb l min ? 0.015 0.125 0.055 0.016 0.045 0.008 0.005 0.300 0.240 0.100 0.300 ? 0.115 max 0.200 ? 0.175 0.080 0.022 0.065 0.012 0.080 0.325 0.310 ? ? 0.400 0.150 min ? 0.38 3.18 1.40 0.41 1.14 0.20 0.13 7.62 6.10 2.54 7.62 ? 2.92 max 5.08 ? 4.45 2.03 0.56 1.65 0.30 2.03 8.26 7.87 ? ? 10.16 3.81 inches millimeters plastic dip plastic dual-in-line package (0.300 in.) dim d d d d d d min 0.348 0.735 0.745 0.885 1.015 1.14 max 0.390 0.765 0.765 0.915 1.045 1.265 min 8.84 18.67 18.92 22.48 25.78 28.96 max 9.91 19.43 19.43 23.24 26.54 32.13 inches millimeters pins 8 14 16 18 20 24 c a a2 e1 d e ea eb a3 b1 b 0?- 15 a1 l d1 e ________________________________________________________package information

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