exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 +5v only low power bicmos driver/receiver enable for multi-drop confgurations low power shutdown mode (sp48e) enhanced esd specifcations: description the sp1481e and the sp1485e are a family of half-duplex transceivers that meet the specifcations of rs-485 and rs-422 serial protocols with enhanced esd performance. the esd tolerance has been improved on these devices to over + 15kv for both human body model and iec1000-4-2 air discharge method. these devices are pin-to-pin compatible with exar's sp481 and sp485 devices as well as popular industry standards. as with the original versions, the sp1481e and the sp1485e feature exar's bicmos design allowing low power operation without sacrifcing performance. the sp1481e and sp1485e meet the requirements of the rs-485 and rs-422 protocols up to 20mbps under load. the sp1481e is equipped with a low power shutdown mode. + 15kv human body model + 15kv iec1000-4-2 air discharge + 8kv iec1000-4-2 contact discharge now available in lead free packaging sp1481e/sp1485e enhanced low power half-duplex rs-485 transceivers
exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 2 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 specifcations below is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. v cc ..............................................................................+7v input voltages logic...................................................-0.3v to (v cc +0.5v) drivers................................................-0.3v to (v cc +0.5v) receivers................................................................. 15v electrical characteristics t min to t max and v cc = 5v 5% unless otherwise noted. parameters min. typ. max. units conditions sp1481e/sp1485e driver dc characteristics differential output voltage 3.5 v cc volts unloaded; r = ; see figure 1 differential output voltage 2 v cc volts with load; r = 50?; (rs-422); see figure 1 differential output voltage 1.5 v cc volts with load; r = 27?; (rs-485);see figure 1 change in magnitude of driver differential output voltage for complimentary states 0.2 volts r = 27? or r = 50?; see figure 1 driver common-mode output voltage 3 volts r = 27? or r = 50?; see 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 sp1481e/sp1485e driver ac characteristics maximum data rate 20 mbps re = 5v, de = 5v; r diff = 54?, c l1 = c l2 = 00pf driver input to output 20 30 ns t plh ; r diff = 54?, c l1 = c l2 = 100pf; see figures 3 and 5 driver input to output 20 30 ns t phl ; r diff = 54?, c l1 = c l2 = 100pf; see figures 3 and 5 driver skew 3 5 ns see figures 3 and 5, t skew = | t plh - t phl | driver rise or fall time 8 20 ns from 10% to 90%; r diff = 54?, c l1 = c l2 = 100pf; s ee figures 3 & 6 driver enable to output high 40 70 ns c l = 100pf; see figures 4 & 6; s 2 closed driver enable to output low 40 70 ns c l = 100pf; see figures 4 & 6; s closed driver disable time from low 40 70 ns c l = 100pf; see figures 4 & 6; s closed driver disable time from high 40 70 ns c l = 100pf; see figures 4 & 6; s 2 closed output voltages logic.............................................-0.3v to (v cc +0.5v) drivers................................................................ 15v receivers......................................-0.3v to (v cc +0.5v) storage temperature.....................................................-65?c to +150?c power dissipation per package 8-pin nsoic (derate 6.60mw/ o c above +70 o c).........................550mw
3 exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 specifications (continued) parameters min. typ. max. units conditions sp1481e/sp148 5e 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 3.5 volts i o = -4ma, v id = +200mv output voltage low 0.4 volts i o = +4ma, v id = -200mv three-state (high impedance) output current 1 a 0.4v v o 2.4v; re = 5v 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 5.25v, v in = 12v input current (a, b); v in = -7v -0.8 ma de = 0v, v cc = 0v or 5.25v, v in = -7v short-circuit current 7 95 ma 0v v o v cc sp1481e/sp1485e receiver ac characteristics maximum data rate 20 mbps re = 0v, de = 0v receiver input to output 25 70 ns t plh ; r diff = 54?, c l1 = c l2 = 100pf; figures 3 & 7 receiver input to output 25 70 ns t phl ; r diff = 54?, c l1 = c l2 = 100pf; figures 3 & 7 diff. receiver skew it plh -t phl i 5 10 ns r diff = 54?; c l1 = c l2 = 100pf; figures 3 & 7 receiver enable to output low 45 70 ns c rl = 15pf; figures 2 & 8; s closed receiver enable to output high 45 70 ns c rl = 15pf; figures 2 & 8; s 2 closed receiver disable from low 45 70 ns c rl = 15pf; figures 2 & 8; s closed receiver disable from high 45 70 ns c rl = 15pf; figures 2 & 8; s 2 closed sp1481e shutdown timing time to shutdown 50 200 600 ns re = 5v, de = 0v driver enable from shutdown to output high 40 100 ns c l = 100pf; see figures 4 & 6; s 2 closed driver enable from shutdown to output low 40 100 ns c l = 100pf; see figures 4 & 6; s closed receiver enable from shutdown to output high 300 1000 ns c l = 15pf; see figures 2 & 8; s 2 closed receiver enable from shutdown to output low 300 1000 ns c l = 15pf; see figures 2 & 8; s closed power requirements supply voltage +4.75 +5.25 volts supply current sp1481e/1485e no load 900 a re, di = 0v or v cc ; de = v cc 600 a re = 0v, di = 0v or 5v; de = 0v sp48e shutdown mode 10 a de = 0v, re=v cc e nv ironmental and me chanical operating temperature commercial (_c_) 0 +70 c industrial (_e_) -40 +85 c storage temperature -65 +150 c package nsoic (_n) t min to t max and v cc = 5v 5% unless otherwise noted
exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 4 pin function pin 1 C ro C receiver output. pin 2 C re C receiver output enable active low. pin 3 C de C driver output enable active high. pin 4 C di C driver input. pin 5 C gnd C ground connection. pin 6 C a C driver output/receiver inpu t non-inverting. pin 7 C b C driver output/receiver input inverting. pin 8 C vcc C positive supply 4.75v 5 exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 table 1. transmit function truth table table 2. receive function truth table +3v 0v de 5v v ol a , b 0v 1.5v 1.5v t zl t zh f = 1mhz; t r < 1ns ; t f < 1ns v oh a , b 2.3v 2.3v t lz t hz 0.5v 0.5v output nor mally low output nor mally high +3v 0v 5v 0v 1.5v 1.5v t zl t zh f = 1mhz; t r 1ns; t f 1ns r 1.5v 1.5v t lz t hz 0.5v 0.5v output nor mally low output nor mally high v il v ih r re figure 8. receiver enable and disable times figure 7. receiver propagation delays figure 6. driver enable and disable times v oh v ol r 1.5v 1.5v t phl f = 1mhz; t r 10ns ; t f 10ns output v od2 + v od2 ? a ? b 0v 0v t plh input inputs outputs re de di line condition a b x no fault 0 x 0 no fault 0 x 0 x x z z x x fault z z inputs outputs re de a - b r 0 0 +0.2v 0 0 -0.2v 0 0 0 inputs open 0 x z
exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 6 a logic low on re (pin 2) will enable the receiver, a logic high on re (pin 2) will dis - able the receiver. the receiver for the sp1481e and sp1485e will operate up to at least 20mbps. the receiver for each of the two devices is equipped with the fail-safe feature. fail-safe guarantees that the receiver output will be in a high state when the input is left unconnected. shutdown mode sp1481e the sp1481e 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 sp1481e into shut - down mode. in shutdown, supply current will drop to typically 1a. esd t olerance the sp1481e family incorporates rug - gedized esd cells on all driver output and receiver input pins. the esd structure is improved over our previous family for more rugged applications and environments sensitive to electro-static discharges and associated transients. the improved esd tolerance is at least 15kv without damage nor latch-up. there are different methods of esd testing applied: a) mil-std-883, method 3015.7 b) iec1000-4-2 air-discharge c) iec1000-4-2 direct contact the human body model has been the generally accepted esd testing method for semiconductors. this method is also specifed in mil-std-883, method 3015.7 for esd testing. the premise of this esd test is to simulate the human bodys potential to store electro-static energy and discharge it to an integrated circuit. the simulation is performed by using a test model as shown in figure 9. this method will test the ics capability to withstand an esd transient dur - ing normal handling such as in manufactur - ing areas where the ics tend to be handled frequently. description the sp1481e and sp1485e are half-duplex differential transceivers that meet the require - ments of rs-485 and rs-422. fabricated with a exar proprietary bicmos process, these products require a fraction of the power of older bipolar designs. the rs-485 standard is ideal for multi-drop applications and for long-distance interfaces. rs-485 allows up to 32 drivers and 32 receiv - ers to be connected to a data bus, making it an ideal choice for multi-drop applications. since the cabling can be as long as 4,000 feet, rs-485 transceivers are equipped with a wide (-7v to +12v) common mode range to accommodate ground potential differ - ences. because rs-485 is a differential interface, data is virtually immune to noise in the transmission line. drivers the driver outputs of the sp1481e and sp1485e are differential outputs meeting the rs-485 and rs-422 standards. the typical voltage output swing with no load will be 0 volts to +5 volts. with worst case loading of 54? across the differential outputs, the drivers can maintain greater than 1.5v volt - age levels. the drivers of the sp1481e, and sp1485e 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 transmitters of the sp1481e and sp1485e will operate up to at least 20mbps. receivers the sp1481e and sp1485e 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 sp1481e and sp1485e have a tri-state enable control pin.
7 exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 the iec-1000-4-2, formerly iec801-2, is generally used for testing esd on equipment and systems. for system manufacturers, they must guarantee a certain amount of esd protection since the system itself is exposed to the outside environment and human pres - ence. the premise with iec1000-4-2 is that the system is required to withstand an amount of static electricity when esd is applied to points and surfaces of the equipment that are accessible to personnel during normal usage. the transceiver ic receives most of the esd current when the esd source is applied to the connector pins. the test circuit for iec1000-4-2 is shown on figure 10. there are two methods within iec1000-4-2, the air discharge method and the contact discharge method. figure 9. esd test circuit for human body model figure 10. esd test circuit for iec1000-4-2 r c devic e under test dc power sourc e c s r s sw1 sw2 r s an d r v add up to 330 for iec1000-4-2. r c device unde r test dc power sourc e c s r s sw1 sw2 r v contact-discharge model
exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 8 with the air discharge method, an esd voltage is applied to the equipment under test (eut) through air. this simulates an electrically charged person ready to connect a cable onto the rear of the system only to fnd an unpleasant zap just before the person touches the back panel. the high energy potential on the person discharges through an arcing path to the rear panel of the system before he or she even touches the system. this energy, whether discharged directly or through air, is predominantly a function of the discharge current rather than the discharge voltage. variables with an air discharge such as approach speed of the object carrying the esd potential to the system and humidity will tend to change the discharge current. for example, the rise time of the discharge current varies with the approach speed. the contact discharge method applies the esd current directly to the eut. this method was devised to reduce the unpredictability of the esd arc. the discharge current rise time is constant since the energy is directly transferred without the air-gap arc. in situ - ations such as hand held systems, the esd charge can be directly discharged to the equipment from a person already holding the equipment. the current is transferred on to the keypad or the serial port of the equipment directly and then travels through the pcb and fnally to the ic. the circuit model in figures 9 and 10 repre - sent the typical esd testing circuit used for all three methods. the c s is initially charged with the dc power supply when the frst switch (sw1) is on. now that the capacitor is charged, the second switch (sw2) is on while sw1 switches off. the voltage stored in the capacitor is then applied through r s , the current limiting resistor, onto the device under test (dut). in esd tests, the sw2 switch is pulsed so that the device under test receives a duration of voltage. for the human body model, the current limiting resistor (r s ) and the source capacitor (c s ) are 1.5k? an 100pf, respectively. for iec-1000-4-2, the current limiting resistor (r s ) and the source capacitor (c s ) are 330? an 150pf, respectively. the higher c s value and lower r s value in the iec1000-4-2 model are more stringent than the human body model. the larger storage capacitor injects a higher voltage to the test point when sw2 is switched on. the lower current limiting resistor increases the current charge onto the test point. t = 0ns t = 30ns 0a 15a 30a i t figure 11. esd test waveform for iec1000-4-2 human b ody iec1000-4-2 model air discharge direct contact level driver outputs 15kv 15kv 8kv 4 receiver inputs 15kv 15kv 8kv 4 sp1481e, sp1485e fami l y
9 exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030
exar corporation 48720 kato road, fremont ca, 94538 ? 50-668-70 7 ? www.exar.com sp48e-485e_0_08030 0 ordering informa tion model temperature range package sp1481ecn-l ................................................... 0?c to +70?c ............................................... 8-pin narrow soic sp1481ecn-l/tr ............................................. .0?c to +70?c ............................................... 8-pin narrow soic sp1481een-l ................................................. .-40?c to +85?c ............................................. 8-pin narrow soic sp1481een-l/tr ........................................... .-40?c to +85?c ............................................. 8-pin narrow soic sp1485ecn-l ................................................... 0?c to +70?c ............................................... 8-pin narrow soic sp1485ecn-l/tr ............................................. 0?c to +70?c ............................................... 8-pin narrow soic sp1485een-l .................................................. -40?c to +85?c .............................................. 8-pin narrow soic sp1485een-l/tr ............................................ -40?c to +85?c .............................................. 8-pin narrow soic notice exar corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reli - ability. exar corporation assumes no representation that the circuits are free of patent infringement. charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specifc application. while the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. exar corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to signifcantly affect its safety or effectiveness. products are not authorized for use in such applications unless exar corporation receives, in writting, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized ; (b) the user assumes all such risks; (c) potential liability of exar corporation is adequately protected under the circumstances. copyright 2010 exar corporation datasheet august 2010 send your interface technical inquiry with technical details to: uarttechsupport@exar.com reproduction, in part or whole, without the prior written consent of exar corporation is prohibited. date revision description 03/08/07 j legacy sipex datasheet 06/16/10 .0.0 convert to exar format, update ordering information and change revision to 1.0.0, remove sp1485emn option. 08/03/10 .0. remove sp1485emn option and change revision to 1.0.1
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