1 10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2002 sipex corporation sp3481/sp3485 rs-485 and rs-422 transceivers operates from a single +3.3v supply interoperable with +5.0v logic driver/receiver enable low power shutdown mode (sp3481) -7v to +12v common-mode input voltage range allows up to 32 transceivers on the serial bus compatibility with the industry standard 75176 pinout driver output short-circuit protection 8 7 6 5 1 2 3 4 vcc b a gnd d r r o re de di sp3481 and sp3485 re description the sp3481 and the sp3485 are a family of +3.3v low power half-duplex transceivers that meet the specifications of the rs-485 and rs-422 serial protocols. these devices are pin-to- pin compatible with the sipex sp481, sp483, and sp485 devices as well as popular industry standards. the sp3481 and the sp3485 feature sipex's bicmos process, allowing low power operation without sacrificing performance. the sp3481 and sp3485 meet the electrical specifications of rs-485 and rs-422 serial protocols up to 10mbps under load. the sp3481 is equipped with a low power shutdown mode. +3.3v low power half-duplex rs-485 t ransceivers with 10mbps data rate now available in lead free packaging
10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2000 sipex corporation 2 specifications t amb = t min to t max and v cc = +3.3v 5% unless otherwise noted. parameters min. typ. max. units conditions sp3481/sp3485 driver dc characteristics differential output voltage gnd v cc volts unloaded; r = ; figure 1 differential output voltage 2 v cc volts with load; r = 50 ? ; (rs-422); figure 1 differential output voltage 1.5 v cc volts with load; r = 27 ? ; (rs-485); figure 1 change in magnitude of driver differential output voltage for complimentary states 0.2 volts r = 27 ? or r = 50 ? ; figure 1 driver common-mode output voltage 3 volts r = 27 ? or r = 50 ? ; figure 1 input high voltage 2.0 volts applies to de, di, re input low voltage 0.8 volts applies to de, di, re input current 10 a applies to de, di, re driver short-circuit current v out = high 250 ma -7v v o +12v v out = low 250 ma -7v v o +12v sp3481/sp3485 driver ac characteristics maximum data rate 10 mbps re = v cc , de = v cc driver input to output, t plh 20 40 60 ns figures 2 and 8 driver input to output, t phl 20 40 60 ns figures 2 and 8 differential driver skew 2 10 ns t do1 - t do2 figures 2 and 9 driver rise or fall time 5 20 ns from 10% to 90% ; figures 3 and 9 driver enable to output high 52 120 ns figures 4 and 10 driver enable to output low 60 120 ns figures 5 and 10 driver disable time from low 40 120 ns figures 5 and 10 driver disable time from high 60 120 ns figures 4 and 10 sp3481/sp3485 receiver dc characteristics differential input threshold -0.2 +0.2 volts -7v v cm +12v input hysteresis 20 mv v cm = 0v output voltage high v cc -0.4 volts v id = +200mv, -1.5ma output voltage low 0.4 volts v id = -200mv, 2.5ma three-state (high impedance) output current +1 a 0v v o v cc ; re = v cc input resistance 12 15 k ? -7v v cm +12v input current (a, b); v in = 12v 1.0 ma de = 0v, v cc = 0v or 3.6v, v in = 12v input current (a, b); v in = -7v -0.8 ma de = 0v, v cc = 0v or 3.6v, v in = -7v short-circuit current 7 60 ma 0v v cm v cc absolute maximum ratings these are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. v cc ............................................................................................. +6.0v input voltages logic ..................................................... -0.3v to +6.0v drivers ................................................... -0.3v to +6.0v receivers ............................................................ 15v output voltages drivers .................................................................. 15v receivers .............................................. -0.3v to +6.0v storage temperature ................................................ .-65?c to +150?c power dissipation per package 8-pin nsoic (derate 6.90mw/ o c above +70 o c) ..................... 600mw 8-pin pdip (derate 11.8mw/ o c above +70 o c) ...................... 1000mw
3 10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2002 sipex corporation specifications (continued) t amb = t min to t max and v cc = +3.3v 5% unless otherwise noted. parameters min. typ. max. units conditions sp3481/sp3485 receiver ac characteristics maximum data rate 10 mbps re = 0v, de = 0v receiver input to output, t plh 40 70 100 ns figures 6 and 11 70 ns t amb = +25 o c, v cc = +3.3v, figures 6 and 11 receiver input to output, t phl 40 70 100 ns figures 6 and 11 70 ns t amb = +25 o c, v cc = +3.3v, figures 6 and 11 differential receiver skew 4 ns t rskew = t rphl - t rplh , figures 6 and 11 receiver enable to output low 35 60 ns figures 7 and 12 ; s 1 closed, s 2 open receiver enable to output high 35 60 ns figures 7 and 12 ; s 2 closed, s 1 open receiver disable from low 35 60 ns figures 7 and 12 ; s 1 closed, s 2 open receiver disable from high 35 60 ns figures 7 and 12 ; s 2 closed, s 1 open sp3481 shutdown timing time to shutdown 50 75 200 ns re = 3.3v, de = 0v driver enable from shutdown to output high 65 150 ns figures 4 and 10 driver enable from shutdown to output low 65 150 ns figures 5 and 10 receiver enable from shutdown to output high 50 200 ns figures 7 and 12; s 2 closed, s 1 open receiver enable from shutdown to output low 50 200 ns figures 7 and 12; s 1 closed, s 2 open power requirements supply current sp3481/3485 no load 1000 2000 a re, di = 0v or v cc ; de = v cc 800 1500 a re = 0v, di = 0v or v cc ; de = 0v sp3481 shutdown mode 10 a de = 0v, re=v cc
10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2000 sipex corporation 4 pin function pin 1 ?ro ?receiver output. pin 2 ?re ?receiver output enable active low. pin 3 ?de ?driver output enable active high. pin 4 ?di ?driver input. pin 5 ?gnd ?ground connection. pin 6 ?a ?driver output/receiver input non-inverting. pin 7 ?b ?driver output/receiver input inverting. pin 8 ?v cc description the sp3481 and the sp3485 are 2 members in the family of +3.3v low power half-duplex transceivers that meet the specifications of the rs-485 and rs-422 serial protocols. these devices are pin-to-pin compatible with the sipex sp481, sp483, and sp485 devices as well as popular industry standards. the sp3481 and the sp3485 feature sipex's bicmos process allowing low power operation without sacrificing performance. drivers the driver outputs of the sp3481 and sp3485 are differential outputs meeting the rs-485 and rs-422 standards. the typical voltage output swing with no load will be 0 volts to +3.3 volts. with a load of 54 ? across the differential outputs, the drivers maintain greater than 1.5v voltage levels. the drivers of the sp3481 and sp3485 have an enable control line which is active high. a logic high on de (pin 3) will enable the differential driver outputs. a logic low on de (pin 3) will tri-state the driver outputs. the tranceivers in the sp3481 and sp3485 operate up to 10mbps. the 250ma i sc maximum limit on the driver output allows the sp3481 and the sp3485 to withstand an infinite short circuit over the -7.0v to +12.0v common mode range without catastrophic damage to the ic. sp3481/sp3485 pinout (top view) ro 1 re 2 de 3 di 4 8 v cc 7 b 6 a 5 gnd d r sp485 top view receivers the sp3481 a nd sp3485 receivers have differential inputs with an input sensitivity as low as 200mv. input impedance of the receivers is typically 15k ? (12k ? minimum). a wide common mode range of -7v to +12v allows for large ground potential differences between systems. the receivers of the sp3481 and sp3485 have a tri-state enable control pin. a logic low on re (pin 2) will enable the receiver, a logic high on re (pin 2) will disable the receiver. the receivers of the sp3481 and sp3485 operate up to 10mbps. the receiver for each of the three devices is equipped with fail-safe. fail-safe guarantees that the receiver output will be in a high state when the input is left unconnected. shutdown mode for the sp3481 the sp3481 is equipped with a shutdown mode. to enable the shutdown state, both the driver and receiver must be disabled simultaneously. a logic low on de (pin 3) and a logic high on re (pin 2) will put the sp3481 into shutdown mode. in shutdown, supply current will drop to typical 1 a, 10 a maximum.
5 10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2002 sipex corporation inputs outputs line re de di condition b a x1 1 no fault 0 1 x1 0 no fault 1 0 x0x x zz inputs outputs re de a - b r 00 +0.2v 1 00 -0.2v 0 00 inputs open 1 10 x z table 1. transmit function truth table table 2. receive function truth table figure 2. driver propagation delay test circuit figure 4. driver enable and disable timing circuit, output high figure 1. driver dc test load circuit figure 6. receiver propagation delay test circuit figure 7. receiver enable and disable timing circuit r r v oc d v cc v od generator (note 1) 50 ? v cc s1 v dm r l = 27 ? out c l = 15pf (note 2) v om = 1.5v v oh + v ol 2 d generator (note 1) 50 ? s1 r l = 110 ? out c l = 50pf (note 2) v om = 1.5v v oh + v ol 2 d generator (note 1) 50 ? s1 r l = 110 ? out c l = 50pf (note 2) d 0v or 3v v cc generator (note 1) 50 ? 1.5v 0v v id r out c l = 15pf (note 2) v om = v cc 2 1.5v -1.5v s3 v id generator (note 1) 50 ? c l = 15pf (note 2) r 1k s1 s2 v cc figure 5. driver enable and disable timing circuit, output low generator (note 1) 50 ? c l out d v cc r l = 60 ? c l = 15pf (note 2) figure 3. driver differential output delay and transition time circuit
10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2000 sipex corporation 6 figure 8. driver propagation delay waveforms figure 12. receiver enable and disable waveforms figure 11. receiver propagation delay waveforms figure 10. driver enable and disable timing waveforms 0v v oh t plh t phl v om t phl t plh 3v v ol v oh 1.5v 1.5v input y output v om z output v ol v om v om v om = v oh + v ol 2 1.5v 0v v oh t pzh 0.25v t phz v om t pzl t plz 3v v ol v cc 1.5v 1.5v de output high v om 0.25v 0v output low v om = v oh + v ol 2 1.5v 3v 0v v cc t rplh 1.5v t rphl v om v om 0v 1.5v input output v om = v cc 2 note 1: the input pulse is supplied by a generator with the following characteristics: prr=250khz, 50% duty cycle, t r < 6.0ns, z 0 =50 ? . note 2: c l includes probe and stray capacitance. in 1.5v t do1 1.5v t do2 3v 0v out 50% 50% 10% 10% 90% 90% t td t td 2.0v -2.0v figure 9. driver differential output delay and transition time waveforms 3v 0v t prhz 1.5v t przh t prsh 1.5v 1.5v 10% 0v v oh re output s1 is open s2 is closed s3 = 1.5v 3v 0v t prlz 1.5v t przl t prsl 1.5v 1.5v 10% v cc re output s1 is closed s2 is open s3 = -1.5v v ol
7 10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2002 sipex corporation d alternate end pins (both ends) d1 = 0.005" min. (0.127 min.) e package: plastic dual?n?ine (narrow) dimensions (inches) minimum/maximum (mm) a = 0.210" max. (5.334 max). e1 c l a2 a1 = 0.015" min. (0.381min.) b b1 e = 0.100 bsc (2.540 bsc) e a = 0.300 bsc (7.620 bsc) a2 b b1 c d e e1 l 0.115/0.195 (2.921/4.953) 0.014/0.022 (0.356/0.559) 0.045/0.070 (1.143/1.778) 0.008/0.014 (0.203/0.356) 0.355/0.400 (9.017/10.160) 0.300/0.325 (7.620/8.255) 0.240/0.280 (6.096/7.112) 0.115/0.150 (2.921/3.810) 0? 15 (0?15? 8?in
10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2000 sipex corporation 8 d eh package: plastic small outline (soic) (narrow) dimensions (inches) minimum/maximum (mm) 8?in a a1 l b e h x 45 a a1 b d e e h h l 0.053/0.069 (1.346/1.748) 0.004/0.010 (0.102/0.249 0.014/0.019 (0.35/0.49) 0.189/0.197 (4.80/5.00) 0.150/0.157 (3.802/3.988) 0.050 bsc (1.270 bsc) 0.228/0.244 (5.801/6.198) 0.010/0.020 (0.254/0.498) 0.016/0.050 (0.406/1.270) 0?8 (0?8?
9 10/15/02 sp3481/3485 low power half-duplex rs485 transceivers ?copyright 2002 sipex corporation ordering information model temperature range package sp3481cn .................................................................................... 0?c to +70?c ............................................................................ 8-pin narrow soic sp3481cp .................................................................................... 0?c to +70?c ................................................................................ 8-pin plastic dip sp3481en .................................................................................. .-40?c to +85?c .......................................................................... 8-pin narrow soic sp3481ep ................................................................................... -40?c to +85?c .............................................................................. 8-pin plastic dip sp3485cn .................................................................................... 0?c to +70?c ............................................................................ 8-pin narrow soic sp3485cp .................................................................................... 0?c to +70?c ................................................................................ 8-pin plastic dip sp3485en ................................................................................... -40?c to +85?c .......................................................................... 8-pin narrow soic sp3485ep ................................................................................... -40?c to +85?c .............................................................................. 8-pin plastic dip please consult the factory for pricing and availability on a tape-on-reel option. corporation signal processing excellence sipex corporation reserves the right to make changes to any products described herein. sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others. sipex corporation headquarters and sales office 233 south hillview drive milpitas, ca 95035 tel: (408) 934-7500 fax: (408) 935-7600 sales office 22 linnell circle billerica, ma 01821 tel: (978) 667-8700 fax: (978) 670-9001 e-mail: sales@sipex.com available in lead free packaging. to order, add "-l" suffix to the part number. example: sp3481cn = standard; sp3481cn -l = lead free.
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