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3.3 v, 15 kv esd-protected, half- and full-duplex, rs-485/rs-422 transceivers ADM3483E/adm3486e/adm3 488e/adm3490e/adm3491e rev. a information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent rights of analog devices. trademarks and registered trademarks are the property of their respective owners. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.461.3113 ?2006 analog devices, inc. all rights reserved. features tia/eia rs-485/rs-422 compliant 15 kv esd protection on rs-485 input/output pins data rates ADM3483E/adm3488e: 250 kbps adm3486e: 2.5 mbps adm3490e/adm3491e: 12 mbps half- and full-duplex options up to 32 nodes on the bus receiver open-circuit, fail-safe design low power shutdown current (ADM3483E/adm3486e/adm3491e only) outputs high-z when disabled or powered off common-mode input range: ?7 v to +12 v thermal shutdown and short-circuit protection industry-standard 75176 pinout 8-lead and 14-lead narrow soic packages applications power/energy metering telecommunications emi-sensitive systems industrial control local area networks general description the ADM3483E/adm3486e/adm3488e/adm3490e/ adm3491e are 3.3 v, low power data transceivers with 15 kv esd protection suitable for full- and half-duplex communication on multipoint bus transmission lines. they are designed for balanced data transmission, and they comply with tia/eia standards rs-485 and rs-422. the ADM3483E/adm3486e are half-duplex transceivers that share differential lines and have separate enable inputs for the driver and receiver. the full-duplex adm3488e/ adm3490e/adm3491e transceivers have dedicated differential line driver outputs and receiver inputs. the adm3491e also features separate enable inputs for the driver and receiver. the devices have a 12 k receiver input impedance, which allows up to 32 transceivers on a bus. because only one driver should be enabled at any time, the output of a disabled or powered-down driver is tristated to avoid overloading the bus. functional block diagrams ADM3483E/ adm3486e ro re de di v cc a b gnd d r 0 6284-001 figure 1. adm3488e/ adm3490e ro di v cc a b z y gnd r d 0 6284-002 figure 2. adm3491e ro re de di v cc a b z y gnd r d 06284-003 figure 3. (continued on page 3)
ADM3483E/adm3486e/adm3 488e/adm3490e/adm3491e rev. a | page 2 of 20 table of contents features .............................................................................................. 1 applications....................................................................................... 1 general description ......................................................................... 1 functional block diagrams............................................................. 1 revision history ............................................................................... 2 specifications..................................................................................... 4 driver timing specifications...................................................... 5 receiver timing specifications .................................................. 6 absolute maximum ratings............................................................ 7 esd caution.................................................................................. 7 pin configurations and function descriptions ........................... 8 test circuits and switching characteristics.................................. 9 typical performance characteristics ........................................... 11 circuit description......................................................................... 14 devices with receiver/driver enableADM3483E/ adm3486e/ adm3491e ........................................................... 14 devices without receiver/driver enable D adm3488e/ adm3490e ................................................................................. 14 low power shutdown modeADM3483E/ adm3486e / adm3491e ................................................................................. 14 driver output protection.......................................................... 14 propagation delay ...................................................................... 14 line length vs. data rate ......................................................... 14 15 kv esd protection ............................................................. 15 human body model .................................................................. 15 typical applications................................................................... 15 outline dimensions ....................................................................... 18 ordering guide .......................................................................... 18 revision history 10/06rev. 0 to rev. a added ADM3483E and adm3488e ...............................universal changes to figure 1 and figure 2................................................... 1 inserted table 3................................................................................. 5 changes to figure 4 and figure 5................................................... 8 inserted figure 28 and figure 29.................................................. 13 changes to figure 31 and figure 32............................................. 16 changes to figure 34...................................................................... 17 updated outline dimensions ....................................................... 18 changes to ordering guide .......................................................... 18 8/06revision 0: initial version
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 3 of 20 general description (continued from page 1) the driver outputs of the ADM3483E/adm3486e/ adm3488e are slew rate limited, in order to reduce emi and data errors caused by reflections from improperly terminated buses. the receiver has a fail-safe feature that ensures a logic high output when the inputs are floating. excessive power dissipation caused by bus contention or by output shorting is prevented with a thermal shut- down circuit. the parts are fully specified over the industrial temperature range and are available in 8-lead and 14-lead narrow soic packages. table 1. selection table part no. guaranteed data rate (mbps) supply voltage (v) half/full duplex slew rate limited driver/receiver enable 15 kv esd protection on bus pins pin count ADM3483E 0.25 3.0 to 3.6 half yes yes yes 8 adm3486e 2.5 3.0 to 3.6 half yes yes yes 8 adm3488e 0.25 3.0 to 3.6 full yes no yes 8 adm3490e 12 3.0 to 3.6 full no no yes 8 adm3491e 12 3.0 to 3.6 full no yes yes 14
ADM3483E/adm3486e/adm3 488e/adm3490e/adm3491e rev. a | page 4 of 20 specifications v cc = 3.3 v 0.3 v, t a = t min to t max , unless otherwise noted. table 2. ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e parameter symbol min typ max unit test conditions/comments driver differential outputs differential output voltage v od 2.0 v r l = 100 (rs-422) (see figure 7) 1.5 v r l = 54 (rs-485) (see figure 7) 1.5 v r l = 60 (rs-485) (see figure 8) |v od | for complementary output states 1 ?v od 0.2 v r l = 54 or 100 (see figure 7) common-mode output voltage v oc 3 v r l = 54 or 100 (see figure 7) |v oc | for complementary output states 1 ?v oc 0.2 v r l = 54 or 100 (see figure 7) short-circuit output current i osd ?250 ma v out = ?7 v 250 ma v out = 12 v output leakage (y, z) (adm3491e only) i o normal mode 20 a de = 0 v, re = 0 v, v cc = 0 v or 3.6 v, v out = 12 v ?20 a de = 0 v, re = 0 v, v cc = 0 v or 3.6 v, v out = ?7 v shutdown mode 1 a de = 0 v, re = v cc , v cc = 0 v or 3.6 v, v out = 12 v ?1 a de = 0 v, re = v cc , v cc = 0 v or 3.6 v, v out = ?7 v logic inputs input high voltage v ih 2.0 v de, di, re input low voltage v il 0.8 v de, di, re logic input current i in1 2 a de, di, re receiver differential inputs differential input threshold voltage v th ?0.2 0.2 v ?7 v < v cm < +12 v input hysteresis ?v th 50 mv v cm = 0 v input resistance (a, b) r in 12 k ? ?7 v < v cm < +12 v input current (a, b) i in2 1.0 ma de = 0 v, v cc = 0 v or 3.6 v, v in = 12 v ?0.8 ma de = 0 v, v cc = 0 v or 3.6 v, v in = ?7 v ro logic output output high voltage v oh v cc ? 0.4 v i out = ?1.5 ma, v id = 200 mv (see figure 9) output low voltage v ol 0.4 v i out = 2.5 ma, v id = 200 mv (see figure 9) short-circuit output current i osr 8 60 ma 0 v < v ro < v cc tristate output leakage current i ozr 1 a v cc = 3.6 v, 0 v < v out < v cc power supply voltage range v cc 3.0 3.6 v supply current i cc 1.1 2.2 ma no load, di = 0 v or v cc , de = v cc , re = 0 v or v cc 0.95 1.9 ma no load, di = 0 v or v cc , de = 0 v, re = 0 v shutdown current i shdn 0.002 1 a de = 0 v, re = v cc , di = 0 v or v cc esd protection a, b, y, z pins 15 kv human body model all pins except a, b, y, z pins 4 kv human body model 1 |v od | and |v oc | are the changes in v od and v oc , respectively, when di input changes state.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 5 of 20 driver timing specifications v cc = 3.3 v, t a = 25c. table 3. ADM3483E/adm3488e parameter symbol min typ max unit test conditions/comments maximum data rate 250 kbps differential output delay t dd 600 900 1400 ns r l = 60 (see figure 10 ) differential output transition time t td 400 740 1200 ns r l = 60 (see figure 10 ) propagation delay from low to high level t plh 700 930 1500 ns r l = 27 (see figure 11 ) from high to low level t phl 700 930 1500 ns r l = 27 (see figure 11 ) |t plh ? t phl | propagation delay skew 1 t pds 50 ns r l = 27 (see figure 11 ) enable/disable timing (ADM3483E only) enable time to low level t pzl 900 1300 ns r l = 110 (see figure 13 ) enable time to high level t pzh 600 800 ns r l = 110 (see figure 12 ) disable time from low level t plz 50 80 ns r l = 110 (see figure 13 ) disable time from high level t phz 50 80 ns r l = 110 (see figure 12 ) enable time from shutdown to low level t psl 1.9 2.7 s r l = 110 (see figure 13 ) enable time from shutdown to high level t psh 2.2 3.0 s r l = 110 (see figure 12 ) 1 measured on |t plh (y) ? t phl (y)| and |t plh (z) ? t phl (z)|. v cc = 3.3 v, t a = 25c. table 4. adm3486e parameter symbol min typ max unit test conditions/comments maximum data rate 2.5 mbps differential output delay t dd 20 42 70 ns r l = 60 (see figure 10 ) differential output transition time t td 15 28 60 ns r l = 60 (see figure 10 ) propagation delay from low to high level t plh 20 42 75 ns r l = 27 (see figure 11 ) from high to low level t phl 20 42 75 ns r l = 27 (see figure 11 ) |t plh ? t phl | propagation delay skew 1 t pds ?6 12 ns r l = 27 (see figure 11 ) enable/disable timing enable time to low level t pzl 52 100 ns r l = 110 (see figure 13 ) enable time to high level t pzh 52 100 ns r l = 110 (see figure 12 ) disable time from low level t plz 40 80 ns r l = 110 (see figure 13 ) disable time from high level t phz 40 80 ns r l = 110 (see figure 12 ) enable time from shutdown to low level t psl 700 1000 ns r l = 110 (see figure 13 ) enable time from shutdown to high level t psh 700 1000 ns r l = 110 (see figure 12 ) 1 measured on |t plh (y) ? t phl (y)| and |t plh (z) ? t phl (z)|.
ADM3483E/adm3486e/adm3 488e/adm3490e/adm3491e rev. a | page 6 of 20 v cc = 3.3 v, t a = 25c. table 5. adm3490e/adm3491e parameter symbol min typ max unit test conditions/comments maximum data rate 12 15 mbps differential output delay t dd 1 22 35 ns r l = 60 (see figure 10) differential output transition time t td 3 11 25 ns r l = 60 (see figure 10) propagation delay from low to high level t plh 7 23 35 ns r l = 27 (see figure 11) from high to low level t phl 7 23 35 ns r l = 27 (see figure 11) |t plh ? t phl | propagation delay skew 1 t pds ?1.4 8 ns r l = 27 (see figure 11) enable/disable timing (adm3491e only) enable time to low level t pzl 42 90 ns r l = 110 (see figure 13) enable time to high level t pzh 42 90 ns r l = 110 (see figure 12) disable time from low level t plz 35 80 ns r l = 110 (see figure 13) disable time from high level t phz 35 80 ns r l = 110 (see figure 12) enable time from shutdown to low level t psl 650 900 ns r l = 110 (see figure 13) enable time from shutdown to high level t psh 650 900 ns r l = 110 (see figure 12) 1 measured on |t plh (y) ? t phl (y)| and |t plh (z) ? t phl (z)|. receiver timing specifications v cc = 3.3 v, t a = 25c. table 6. ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e parameter symbol min typ max unit test conditions/comments propagation delay from low to high level t rplh adm3486e/adm3490e/adm3491e 25 62 90 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) ADM3483E/adm3488e 25 75 120 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) from high to low level t rphl adm3486e/adm3490e/adm3491e 25 62 90 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) ADM3483E/adm3488e 25 75 120 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) |t rplh ? t rphl | propagation delay skew t rpds adm3486e/adm3490e/adm3491e +6 10 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) ADM3483E/adm3488e +12 20 ns v id = 0 v to 3.0 v, c l = 15 pf (see figure 14) enable/disable timing (ADM3483E/adm3486e/ adm3491e only) enable time to low level t rpzl 25 50 ns c l = 15 pf (see figure 15) enable time to high level t rpzh 25 50 ns c l = 15 pf (see figure 15) disable time from low level t rplz 25 45 ns c l = 15 pf (see figure 15) disable time from high level t rphz 25 45 ns c l = 15 pf (see figure 15) enable time from shutdown to low level t rpsl 720 1400 ns c l = 15 pf (see figure 15) enable time from shutdown to high level t rpsh 720 1400 ns c l = 15 pf (see figure 15) time to shutdown 1 t shdn 80 190 300 ns 1 the transceivers are put into shutdown mode by bringing the re high and the de low. if the inputs are in this state for less than 80 ns, the parts are guaranteed not to enter shutdown. if the part s are in this state for 300 ns or more, the parts are guaranteed to enter shutdown.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 7 of 20 absolute maximum ratings t a = 25c, unless otherwise noted. table 7. parameter rating v cc to gnd ?0.3 v to +6 v digital input/output voltage (de, re , di) ?0.3 v to +6 v receiver output voltage (ro) ?0.3 v to (v cc + 0.3 v) driver output (a, b, y, z)/receiver input (a, b) voltage ?8 v to +13 v driver output current 250 ma operating temperature range ?40c to +85c storage temperature range ?65c to +150c ja thermal impedance 8-lead soic_n 158c/w 14-lead soic_n 120c/w lead temperature, soldering (20 sec) 260c stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. esd caution
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 8 of 20 pin configurations a nd function descriptions ro 1 re 2 de 3 di 4 v cc 8 b 7 a 6 gnd 5 ADM3483E/ adm3486e top view (not to scale) 06284-004 v cc 1 ro 2 di 3 gnd 4 a 8 b 7 z 6 y 5 adm3488e/ adm3490e top view (not to scale) 06284-005 nc 1 ro 2 re 3 de 4 v cc 14 v cc 13 a 12 b 11 di 5 z 10 gnd 6 y 9 gnd 7 nc nc = no connect 8 adm3491e top view (not to scale) 06284-006 figure 4. ADM3483E/adm3486e pin configuration figure 5. adm3488e/adm3490e pin configuration figure 6. adm3491e pin configuration table 8. pin function descriptions ADM3483E/ adm3486e pin no. adm3488e/ adm3490e pin no. adm3491e pin no. mnemonic description 1 2 2 ro receiver output. if a > b by 200 mv, ro is high; if a < b by 200 mv, ro is low. 2 n/a 3 re receiver output enable. a low level en ables the receiver output. a high level places it in a high impedance state. if re is high and de is low, the device enters a low power shutdown mode. 3 n/a 4 de driver output enable. a high level enables the driver differential a and b outputs. a low level places it in a high impedance state. if re is high and de is low, the device enters a low power shutdown mode. 4 3 5 di driver input. with a half-duplex part when the driver is enabled, a logic low on di forces a low and b high; a logic high on di forces a high and b low. with a full-duplex part when the driver is enabled, a logic low on di forces y low and z high; a logic high on di forces y high and z low. 5 4 6, 7 gnd ground. n/a 5 9 y noninverting driver output. 6 n/a n/a a noninverting receiver inp ut a and noninverting driver output a. n/a 8 12 a noninverting receiver input a. n/a 6 10 z inverting driver output. 7 n/a n/a b inverting receiver input b and inverting driver output b. n/a 7 11 b inverting receiver input b. 8 1 13, 14 v cc power supply, 3.3 v 0.3 v. bypass v cc to gnd with a 0.1 f capacitor. n/a n/a 1, 8 nc no connect. not interna lly connected. can be connected to gnd.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 9 of 20 test circuits and switching characteristics v oc r l /2 r l /2 z y v od 06284-007 figure 7. driver differential output voltage and common-mode output voltage r l 375? 375? v od v cm = ?7v to +12v d v cc 06284-008 figure 8. driver differential output voltage with varying common-mode voltage v oh i oh (?) v id r 0 i ol (+) v ol 06284-009 figure 9. receiver output volt age high and output voltage low in out +1.5v +1.5v +3v 0v +2v ?2v t dd t dd t td t td 50% 50% 10% 10% 90% 90% d generator 1 v cc 50? c l r l = 60? c l = 15pf 2 out 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 06284-010 figure 10. driver differential output delay and transition times 3v 0v v oh v ol v oh v ol v om v om v om v om in y out z out 1.5v 1.5v t plh t phl t phl t plh d v om r l = 27 ? out c l = 15pf 2 generator 1 v cc 50? s1 v om = v oh + v ol 2 1.5v 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 06284-011 figure 11. driver propagation delays d out c l = 50pf 2 generator 1 50 ? s1 v om = v oh + v ol 2 1.5v r l = 110 ? 0v or 3v 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 0v v oh 0v 3v 1.5v 1.5v 0.25v in out v om t pzh t phz 06284-012 figure 12. driver enable and disable times (t pzh , t psh , t phz )
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 10 of 20 v ol v cc 0v 3v 0.25v in out 1.5v 1.5v t psl t plz v om d out c l = 50pf 2 generator 1 50 ? s1 0v or 3v v cc r l = 110 ? 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 06284-013 figure 13. driver enable and disable times (t pzl , t psl , t plz ) 3v 0v v cc 0v in out v om v om 1.5v 1.5v t rphl t rplh generator 1 50? c l = 15pf 2 r 1.5v 0v v om = v cc 2 out v id 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 06284-014 figure 14. receiver propagation delays +3v 0v v oh 0v s1 open s2 closed s3 = +1.5v s1 closed s2 open s3 = ?1.5v s1 open s2 closed s3 = +1.5v s1 closed s2 open s3 = ?1.5v +3v 0v v cc v ol +3v 0v v cc v ol +3v 0v v oh 0v +1.5v +1.5v +1.5v in out in out in out in out t rpzl t rpsl t rplz t rphz +0.25v +0.25v +1.5v +1.5v +1.5v t rpzh t rpsh r generator 1 50 ? c l 2 s3 s1 s2 v cc +1.5v ?1.5v v id 1k? 1 ppr = 250khz, 50% duty cycle, t r 6.0ns, z o = 50 ? . 2 c l includes probe and stray capacitance. 06284-015 figure 15. receiver enable and disable times
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 11 of 20 output low voltage (v) output current (ma) typical performance characteristics 25 0 03 . 5 0.5 1.0 1.5 2.0 2.5 3.0 20 15 10 5 06284-021 figure 16. output current vs. receiver output low voltage ? 18 0 03 . 5 output high voltage (v) output current (ma) 0.5 1.0 1.5 2.0 2.5 3.0 ?16 ?14 ?12 ?10 ?8 ?6 ?4 ?2 06284-022 figure 17. output current vs. receiver output high voltage temperature (c) output high voltage (v) 3.00 3.05 3.10 3.15 3.20 3.25 3.30 ?50 ?25 0 25 50 75 i ro = ?1.5ma 06284-023 figure 18. receiver output high voltage vs. temperature temperature (c) output low voltage (v) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 ?40 10 60 85 i ro = 2.5ma 06284-024 100 0 03 . 5 differential output voltage (v) output current (ma) figure 19. receiver output low voltage vs. temperature 0.5 1.0 1.5 2.0 2.5 3.0 90 80 70 60 50 40 30 20 10 06284-025 figure 20. driver output current vs. differential output voltage 2.6 1.6 ?50 temperature (c) differential output voltage (v) ?25 0 25 50 75 2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 r l = 54 ? 06284-026 figure 21. driver differential output voltage vs. temperature
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 12 of 20 output low voltage (v) output current (ma) 0 20 40 60 80 100 120 024681012 06284-027 figure 22. output current vs . driver output low voltage output high voltage (v) output current (ma) 0 20 40 60 80 100 120 ?7?6?5?4?3?2?101234 06284-028 figure 23. output current vs. driver output high voltage 1.2 0.5 ?40 temperature (c) supply current (ma) ?10 20 50 80 1.1 1.0 0.9 0.8 0.7 0.6 06284-029 figure 24. supply current vs. temperature 0.9 0 ?50 temperature (c) shutdown current (a) ?25 0 25 50 75 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 06284-030 figure 25. shutdown current vs. temperature ch1 1.0v ? ch2 1.0v ? it 400ps/pt ch3 2.0v ? m20ns 1.25gs/s a ch3 1.44v 3 c h1 c h2 y z di 06284-031 figure 26. adm3490e/adm3491e driver propagation delay ch3 2.0v 4ns/pt math1 2.01v 200ns m200ns 250ms/s a ch2 1.24v 3 m1 v a ? v b ro ? 06284-032 figure 27. adm3490e/adm3491e receiver propagation delay, driven by external rs-485 device
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 13 of 20 06284-033 ch1 500mv ? ch2 500mv ? ch3 5.0v ? m2.0s 25.0ms/s 40.0ns/pt a ch3 2.4v 3 di y z figure 28. ADM3483E/adm3488e driver propagation delay 06284-034 ch1 2.00v math 2.00v 20.0ms m20.0ms a ch1 40.0mv 1 m v a ? v b ro figure 29. ADM3483E/adm3488e receiver propagation delay
ADM3483E/adm3486e/adm3 488e/adm3490e/adm3491e rev. a | page 14 of 20 circuit description the adm34xxe are low power transceivers for rs-485 and rs-422 communications. the ADM3483E/adm3488e operate at data rates up to 250 kbps. the adm3486e operates at data rates up to 2.5 mbps, and the adm3490e/adm3491e transmit at up to 12 mbps. the adm3488e/adm3490e/adm3491e are full- duplex transceivers, and the ADM3483E/adm3486e are half duplex. driver enable (de) and receiver enable ( re ) pins are included on the ADM3483E/adm3486e/adm3491e. when disabled, the driver and receiver outputs are high impedance. devices with receiver/driver enable ADM3483E/ adm3486e/ adm3491e table 9. transmitting truth table transmitting inputs transmitting outputs re de di a 1 , y 2 b 1 , z 2 mode x 3 1 1 1 0 normal x 3 1 0 0 1 normal 0 0 x 3 high-z 4 high-z 4 normal 1 0 x 3 high-z 4 high-z 4 shutdown 1 ADM3483E and adm3486e only. 2 adm3491e only. 3 x = dont care. 4 high-z = high impedance. table 10. receiving truth table receiving inputs receiving output re de 1 de 2 a C b ro mode 0 0 x 3 +0.2 v 1 normal 0 0 x 3 ?0.2 v 0 normal 0 0 x 3 inputs open 1 normal 1 0 x 3 x 3 high-z 4 shutdown 1 ADM3483E and adm3486e only. 2 adm3491e only. 3 x = dont care. 4 high-z = high impedance. devices without receiver/driver enable D adm3488e/ adm3490e table 11. transmitting truth table transmitting input transmitting outputs di z y 1 0 1 0 1 0 table 12. receiving truth table receiving input receiving output a C b ro +0.2 v 1 ?0.2 v 0 inputs open 1 low power shutdown modeADM3483E/ adm3486e/ adm3491e the ADM3483E/adm3486e/adm3491e are put into a low power shutdown mode by bringing both re high and de low. the devices do not shut down unless both the driver and the receiver are disabled (high impedance). in shutdown mode, the devices typically draw less than 1 a of supply current. for these devices, the t psh and the t psl enable times assume the part was in the low power shutdown mode; the t pzh and the t pzl enable times assume the receiver or the driver was disabled, but the part was not shut down. driver output protection the adm34xxe family implements two ways to prevent excessive output current and power dissipation caused by faults or by bus contention. a current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see the typical performance characteristics section). in addition, a thermal shutdown circuit forces the driver outputs into a high impedance state if the die temperature rises excessively. propagation delay figure 11, figure 14, figure 26, and figure 27 show the typical propagation delays. skew time is simply the difference between the low-to-high and the high-to-low propagation delays. small driver/receiver skew times help maintain a symmetrical mark- space ratio (50% duty cycle). the receiver skew time, |t prhl C t prhl |, is under 10 ns (20 ns for the ADM3483E/adm3488e). the driver skew time is 8 ns for the adm3490e/adm3491e, 12 ns for the adm3486e, and typically under 50 ns for the ADM3483E/adm3488e. 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, figure 34 illustrates an example of a line repeater.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 15 of 20 15 kv esd protection two coupling methods are used for esd testing: con- tact discharge and air-gap discharge. contact discharge calls for a direct connection to the unit being tested. air- gap discharge uses a higher test voltage but does not make direct contact with the test unit. with air-gap discharge, the discharge gun is moved toward the unit under test, developing an arc across the air gap, therefore the term air- gap discharge. this method is influenced by humidity, temperature, barometric pressure, distance, and rate of closure of the discharge gun. the contact discharge method, while less realistic, is more repeatable and is gaining acceptance and preference over the air- gap method. although very little energy is contained within an esd pulse, the extremely fast rise time, coupled with high voltages, can cause failures in unprotected semiconductors. catastrophic destruction can occur immediately as a result of arcing or heating. even if catastrophic failure does not occur immediately, the device can suffer from parametric degradation that can result in degraded performance. the cumulative effects of continuous exposure can eventually lead to complete failure. input/output lines are particularly vulnerable to esd damage. simply touching or connecting an input/output cable can result in a static discharge that can damage or completely destroy the interface product connected to the input/output port. it is extremely important, therefore, to have high levels of esd protection on the input/output lines. the esd discharge can induce latch-up in the device under test, so it is important that esd testing on the input/output pins be carried out while device power is applied. this type of testing is more representative of a real-world input/output discharge, which occurs when the equipment is operating normally. the transmitter outputs and receiver inputs of the adm34xxe family are characterized for protection to a 15 kv limit using the human body model. human body model figure 30 shows the human body model and the current wave- form it generates when discharged into a low impedance. this model consists of a 100 pf capaci tor charged to the esd voltage of interest, which is then discharged into the test device through a 1.5 k resistor. 100% 90% 36.8 % 10% t rl t dl i peak time t r2 c1 r1 high voltage generator device under test esd test method human body model esd assoc. std 55.1 r2 1.5k ? c1 100pf 06284-016 figure 30. human body model and current waveform typical applications the ADM3483E/adm3486e/adm3491e transceivers are designed for bidirectional data communications on multipoint bus transmission lines. the adm3488e/adm3490e full-duplex transceiver is designed to be used in a daisy-chain network topology or in a point-to-point application (see figure 32 ). the ADM3483E/adm3486e are half-duplex rs-485 transceivers that can be used in a multidrop bus configuration, as shown in figure 31 . the adm3488e/adm3490e/adm3491e can also be used as a line repeater, for use with cable lengths longer than 4000 feet, as shown in figure 34 . to minimize reflections, the line must be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 16 of 20 b a r d ro di de ADM3483E/ adm3486e ADM3483E/ adm3486e ADM3483E/ adm3486e ADM3483E/ adm3486e b a r d ro di de b a r d ro re di de b a r d ro re di de r t r t notes 1. maximum number of transceivers on bus: 32. 2. r t is equal to the characteristic impedance of the cable used. re re 06284-017 figure 31. ADM3483E/adm3486e typical half-duplex rs-485 network b a r d ro di ro di y z b a y z maste r r d sl a v e adm3488e/ adm3490e adm3488e/ adm3490e 06284-018 figure 32. adm3488e/adm3490e full-duplex point-to-point applications
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 17 of 20 r d ro di de adm3491e notes 1. maximum number of nodes: 32. 2 . r t is equal to the characteristic impedance of the cable used. a b y z ro r t r t r d ro di de adm3491e slave ab y z r di de adm3491e b a z y d r d ro di de adm3491e slave master sl a v e ab y z re re re re 06284-019 figure 33. adm3491e full-duplex rs-485 network r d ro re di data in data out de adm3488e/ adm3490e/ adm3491e notes 1. r t is equal to the characteristic impedance of the cable used. 2. re and de pins on adm3491e only. a b y z r t r t 06284-020 figure 34. line repeater for adm3488e/adm3490e/adm3491e
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 18 of 20 outline dimensions controlling dimensions are in millimeters; inch dimensions (in parentheses) are rounded-off millimeter equivalents for reference only and are not appropriate for use in design. compliant to jedec standards ms-012-a a 060506-a 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 1.75 (0.0688) 1.35 (0.0532) seating plane 0.25 (0.0098) 0.10 (0.0040) 4 1 85 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) bsc 6.20 (0.2440) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122) coplanarity 0.10 figure 35. 8-lead standard small outline package [soic_n] narrow body (r-8) dimensions shown in millimeters and (inches) controlling dimensions are in millimeters; inch dimensions (in parentheses) are rounded-off millimeter equivalents for reference only and are not appropriate for use in design. compliant to jedec standards ms-012-ab 060606-a 14 8 7 1 6.20 (0.2441) 5.80 (0.2283) 4.00 (0.1575) 3.80 (0.1496) 8.75 (0.3445) 8.55 (0.3366) 1.27 (0.0500) bsc seating plane 0.25 (0.0098) 0.10 (0.0039) 0.51 (0.0201) 0.31 (0.0122) 1.75 (0.0689) 1.35 (0.0531) 0.50 (0.0197) 0.25 (0.0098) 1.27 (0.0500) 0.40 (0.0157) 0.25 (0.0098) 0.17 (0.0067) coplanarity 0.10 8 0 45 figure 36. 14-lead standard small outline package [soic_n] narrow body (r-14) dimensions shown in millimeters and (inches) ordering guide model temperature range package description package option ordering quantity ADM3483Earz 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 ADM3483Earz-reel7 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 1,000 adm3486earz 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 adm3486earz-reel7 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 1,000 adm3488earz 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 adm3488earz-reel7 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 1,000 adm3490earz 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 adm3490earz-reel7 1 C40c to +85c 8-lead standard small outline package (soic_n) r-8 1,000 adm3491earz 1 C40c to +85c 14-lead standard small outline package (soic_n) r-14 adm3491earz-reel7 1 C40c to +85c 14-lead standard small outline package (soic_n) r-14 1,000 1 z = pb-free part.
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 19 of 20 notes
ADM3483E/adm3486e/adm3488e/adm3490e/adm3491e rev. a | page 20 of 20 ?2006 analog devices, inc. all rights reserved. trademarks and registered trademarks are the property of their respective owners. d06284-0-10/06(a) notes

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