sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 1 n allows over 400 transceivers on a transmission line n high impedance on receiver inputs (r in = 150k w typical) n half-duplex configuration consistant with industry standard pinout n C7v to +12v common mode input voltage range n includes shutdown mode (i cc < 10 m a) (for SP481R only) n low power consumption (250mw) n separate driver and receiver enable description the SP481R and sp485r are our newest members of sipex's rs-485 family. the SP481R and sp485r are pin-to-pin equivalent with our existing sp485 product and contain enhancements such as higher esd tolerance and high receiver input impedance. the higher receiver input impedance allows for connecting over 400 transceivers on a single transmission line without degrading the rs-485 driver signal. each device is packaged in an 8-pin plastic dip or 8-pin narrow soic package. the SP481R offers a shutdown feature via the enable pins which will reduce the supply current (i cc ) below 1 m a typical. ro 1 re 2 de 3 di 4 8 v cc 7 b 6 a 5 gnd d r sp485 top view SP481R/sp485r high-fanout rs-485 transceiver ?
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 2 specifications typically 25 c @ vcc = +5v unless otherwise noted. min. typ. max. units conditions logic inputs v il 0.8 volts v ih 2.0 volts logic outputs v ol 0.4 volts i out = -3.2ma v oh 2.4 volts i out = 1.0ma rs-485 driver dc characteristics ttl input levels v il 0.8 volts v ih 2.0 volts outputs open circuit voltage 6.0 volts differential output 1.5 5.0 volts r l =54 w , c l =50pf balance 0.2 volts |v t | - |v t | common-mode output 3.0 volts output current 28.0 ma r l =54 w short circuit current 250 ma terminated in C7v to +12v ac characteristics maximum data rate 5 mbps r l =54 w output transition time 30 ns rise/fall time, 10%C90% propagation delay see figures 3 and 5 t phl 60 100 ns r diff =54 w , c l1 =c l2 =100pf t plh 60 100 ns r diff =54 w , c l1 =c l2 =100pf driver output skew 5 15 ns see figure 3 and 5, t skew = | t dplh - t dphl | rs-485 receiver dc characteristics ttl output levels v ol 0.4 volts v oh 2.4 volts tri-state output current 1 m a 0.4v v out 2.4v; re = v cc inputs common mode range C7.0 +12.0 volts receiver sensitivity 0.2 volts C7v v cm +12v input impedance 120 150 k w C7v v cm +12v 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 ...........................................................................+7v storage temperature..........................-65?c to +150?c power dissipation 8-pin plastic dip...........................1000mw 8-pin plastic n-soic.......................1000mw package derating: 8-pin plastic dip ? ja ....................................................62 c/w 8-pin plastic n-soic ? ja ....................................................62 c/w
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 3 +1.0ma ?.6ma +12v +6v ?v ?v 1 unit load maximum input current versus voltage rs-485 receiver receiver input graph specifications typically 25 c @ vcc = +5v unless otherwise noted. min. typ. max. units conditions ac characteristics maximum data rate 1 mbps propagation delay see figures 3 and 7 t phl 1200 ns r diff =54 w , c l1 =c l2 =100pf t plh 1200 ns r diff =54 w , c l1 =c l2 =100pf differential receiver skew 60 ns | t plh C t phl |; r diff =54 w , c l1 =c l2 =100pf, see figures 3 and 7 shutdown timing (SP481R) time to shutdown 50 600 ns re = v cc , de = 0v rs-485 driver enable time see figures 4 and 6 enable to low 40 500 ns c l =15pf, s 1 closed enable to high 40 500 ns c l =15pf, s 2 closed disable time see figures 4 and 6 disable from low 40 500 ns c l =15pf, s 1 closed disable from high 40 500 ns c l =15pf, s 2 closed rs-485 receiver enable time see figures 2 and 8 enable to low 40 500 ns c l =15pf, s 1 closed enable to high 40 500 ns c l =15pf, s 2 closed disable time see figures 2 and 8 disable from low 40 500 ns c l =15pf, s 1 closed disable from high 40 500 ns c l =15pf, s 2 closed power requirements supply voltage v cc +4.75 +5.25 volts supply current i cc no load 300 500 m a re = v cc or 0v, de = 0v no load 500 900 m a re = v cc or 0v, de = v cc supply current in shutdown 0.5 10 m a re = v cc , de = ov environmental operating temperature commercial (..c..) 0 +70 c industrial (..e..) C40 +85 c storage temperature C65 +150 c
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 4 figure 5. driver propagation delays figure 3. driver/receiver timing test circuit figure 4. driver timing test load #2 circuit figure 1. driver dc test load circuit figure 2. receiver timing test load circuit c l1 15pf ro a b a b di c l2 r l a b r r v od v oc 500 w c l output under test s 1 s 2 v cc 1k w 1k w c rl receiver output s 1 s 2 test point v cc test circuits switching waveforms +3v 0v di b a driver output v o + differential output v a ?v b 0v v o 1.5v 1.5v t plh t r t f f = 1mhz; t r < 10ns; t f < 10ns v o 1/2v o 1/2v o t phl t skew = | t dplh - t dphl | t dplh t dphl t plh
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 5 figure 6. driver enable and disable times figure 7. receiver propagation delays v oh v ol receiver out 1.5v 1.5v t phl f = 1mhz; t r < 10ns; t f < 10ns output v 0d2 + v 0d2 a ?b 0v 0v t plh input t skew = | t phl - t plh | figure 8. receiver enable and disable times +3v 0v de 5v v ol a, b 0v 1.5v 1.5v t zl t zh f = 1mhz; t r < 10ns; t f < 10ns v oh a, b 2.3v 2.3v t lz t hz 0.5v 0.5v output normally low output normally high +3v 0v re 5v 0v 1.5v 1.5v t zl t zh f = 1mhz; t r < 10ns; t f < 10ns receiver out 1.5v 1.5v t lz t hz 0.5v 0.5v output normally low output normally high v il v ih receiver out
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 6 the receiver contains a enable pin (re) which enables the receiver when a logic low is asserted. a logic high will tri-state the receiver output and the inputs will maintain at least 120k w impedance. the receiver can operate to at least 1mbps. the receiver also contains a fail-safe feature which outputs a logic high when the inputs are open as in a disconnected cable. shutdown mode the SP481R includes a shutdown function to reduce power consumption. the shutdown is activated by simultaneously applying a logic low to de and a logic high to re. while in the shutdown mode, the power supply current is typically less than 1 m a. the driver outputs are disabled and are at a high impedance state determined by the receiver input impedance which should be at least 120k w . the receiver output is at also at high impedance during shutdow. output leakage current when the receiver is disabled is under 1 m a. general description the sp485r is a low power rs-485 differential transceiver. similar to the sp485, the sp485r contains a half-duplex driver and receiver with tri-state control. however, the sp485r is in- tended for increased connections on a single bus compared to the orignal rs-485 specification. the rs-485 standard is ideal for multi-drop applications where one bus can contain many drivers and/or receivers. the rs-485 specifica- tion allows up to 32 transceivers to be connected on to the data bus. rs-485 is also specified for driving higher speeds over long cable lengths of up to 4,000 feet. drivers the driver output complies with the rs-485 electrical characteristics as specified by the standard. the output swings from 0v to v cc and decreases to greater than +1.5v with a 54 w load attached between the two outputs. in adhering to the rs-485 specification, the driver outputs inherently comply with the rs-422 standard. with a load of 100 w between the two outputs, the driver can sustain at least +2.0v. the driver contains an enable pin (de) which tri-states the output when de is a logic low. the outputs during the tri-stated condition are at a high impedance (>100k w ). a logic high enables the driver for normal operation. the driver can operate to at least 5mbps . receivers the sp485r receiver has differential inputs with an input sensitivity of lower than 200mv. as mentioned above, the rs-485 specification allows up to 32 transceivers on a the same bus. the sp485r allows over 400 transceivers on the same bus due to the high input impedance of at least 98k w . this higher capacity allows more components to be attached to the same bus without degrading the signal quality. the drivers are still able to drive an equivalent 54 w from the 320 transceivers with an input impedance of at least 120k w in parallel along with the two 125 w cable termination resistors on each end.
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 7 d alternate end pins (both ends) d1 = 0.005" min. (0.127 min.) e package: 8-pin plastic dualCinCline (narrow) e1 c ? e = 0.100 bsc (2.540 bsc) e a = 0.300 bsc (7.620 bsc) b b1 a = 0.210" max. (5.334 max). l a2 a1 = 0.015" min. (0.381min.) dimensions (inches) minimum/maximum (mm) 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 ) 8Cpin
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 8 d e h package: 8-pin plastic small outline (soic) (narrow) a a1 ? l b e h x 45 dimensions (inches) minimum/maximum (mm) 8Cpin 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 )
sp485rds/08 sp485r rs-485 serial transceiver ? copyright 2000 sipex corporation 9 ordering information model temperature range package types SP481Rcp ........................................................................ 0 c to +70 c ...................................................................................... 8Cpin plastic dip SP481Rcn ........................................................................ 0 c to +70 c ...................................................................... 8Cpin plastic narrow soic sp485rcp ........................................................................ 0 c to +70 c ...................................................................................... 8Cpin plastic dip sp485rcn ........................................................................ 0 c to +70 c ...................................................................... 8Cpin plastic narrow soic sipex corporation reserves the right to make changes to any products described herein. sipex does not assume any liability aris ing out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor t he rights of others. corporation signal processing excellence please consult the factory for pricing and availability on a tape-on-reel option. sipex corporation headquarters and sales office 22 linnell circle billerica, ma 01821 tel: (978) 667-8700 fax: (978) 670-9001 e-mail: sales@sipex.com sales office 233 south hillview drive milpitas, ca 95035 tel: (408) 934-7500 fax: (408) 935-7600
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