View ISL4485EIB-T_1579034.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 ? fn6049.1 isl4485e 15kv esd protected, 20mbps, 5v, low power, rs-485/rs-422 transceiver the intersil isl4485e is a high speed, bicmos 5v powered, single transceiver th at meets both the rs-485 and rs-422 standards for balanced communication. each driver output/receiver input is protected against 15kv esd strikes, without latch-up. unlik e competitive devices, this intersil device is specified for 10% tolerance supplies (4.5v to 5.5v). the excellent differential out put voltage coupled with high drive-current output stages al low 20mbps operation over twisted pair networks up to 450 feet in length. the 25k ? receiver input resistance presents a ?single unit load? to the rs-485 bus, allowing up to 32 transceivers on the network. receiver (rx) inputs feature a ?fail-safe if open? design, which ensures a logic high rx output if rx inputs are floating. driver (tx) outputs are short circuit protected, even for voltages exceeding the power supply voltage. additionally, on-chip thermal shutdown circuitr y disables the tx outputs to prevent damage if power dissipation becomes excessive. the half duplex configuration multiplexes the rx inputs and tx outputs to allow transceivers with rx and tx disable functions in 8 lead packages. pinout isl4485e (soic) top view features ? high data rates. . . . . . . . . . . . . . . . . . . . . up to 20mbps ? rs-485 i/o pin esd protection . . . . . . . . . . 15kv hbm - class 3 esd level on all other pins . . . . . . >7kv hbm ? operates from a single +5v supply (10% tolerance) ? 1 unit load allows up to 32 devices on the bus ? low quiescent current . . . . . . . . . . . . . . . . . . . . . 590 a ? -7v to +12v common mode input voltage range ? three state rx and tx outputs ? 30ns propagation delays, 2ns skew ? current limiting and thermal shutdown for driver overload protection applications ? scsi ?fast 20? drivers and receivers ? data loggers ? security networks ? building environmental control systems ? industrial/process control networks ? level translators ordering information part no. (brand) temp. range ( o c) package pkg. dwg. # isl4485eib (4485eib) -40 to 85 8 ld soic m8.15 ISL4485EIB-T (4485eib) -40 to 85 8 ld soic tape & reel m8.15 ro re de di 1 2 3 4 8 7 6 5 v cc b / z a / y gnd d r data sheet december 2003 caution: these devices are sensitive to electrosta tic discharge; follow proper ic handling procedures. 1-888-intersil or 321-724-7143 | intersil (and design) is a registered trademark of intersil americas inc. copyright ? intersil americas inc. 2003. all rights reserved. all other trademarks mentioned are the property of their respective owners.
2 truth tables transmitting inputs outputs re de di b/z a/y x1101 x1010 x 0 x high-z high-z receiving inputs output re de a-b ro 00 +0.2v 1 00 -0.2v 0 0 0 inputs open 1 1 x x high-z pin descriptions pin function ro receiver output: if a > b by at least 0.2v, ro is high; if a < b by 0.2v or more, ro is low; ro = high if a and b are unconne cted (floating). re receiver output enable. ro is enabled when re is low; ro is high impedance when re is high. de driver output enable. the driver outputs, y and z, are enabled by bringing de high. they are high impedance when de is low. di driver input. a low on di forces output y low and output z hi gh. similarly, a high on di forces output y high and output z lo w. gnd ground connection. a / y 15kv hbm esd protected, noninverting receiver input and noninverting driver output. pin is an input (a) if de = 0; pin is an ou tput (y) if de = 1. b / z 15kv hbm esd protected, inverting receiver input and inverting dr iver output. pin is an input (b) if de = 0; pin is an output ( z) if de = 1. v cc system power supply input (4.5v to 5.5v). typical operating circuit 0.1 f + d r 7 6 8 1 2 3 4 5 v cc gnd ro re de di a/y b/z +5v 0.1 f + d r 6 7 8 1 2 3 4 5 v cc gnd ro re de di a/y b/z +5v r t r t isl4485e isl4485e
3 absolute maximum rati ngs thermal information v cc to ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7v input voltages di, de, re . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5v to (v cc +0.5v) input / output voltages a / y, b / z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -8v to +12.5v ro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5v to (v cc +0.5v) short circuit duration y, z. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . continuous esd rating . . . . . . . . . . . . . . . . . . . . . . . . . see specification table operating conditions temperature range isl4485eib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40 o c to 85 o c thermal resistance (typical, note 1) ja ( o c/w) 8 ld soic package . . . . . . . . . . . . . . . . . . . . . . . . . 170 moisture sensitivity (see technical brief tb363) all packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . level 1 maximum junction temperature (plastic package) . . . . . . . 150 o c maximum storage temperature range . . . . . . . . . -65 o c to 150 o c maximum lead temperature (soldering 10s) . . . . . . . . . . . . 300 o c (lead tips only) caution: stresses above those listed in ?abs olute maximum ratings? may cause permanent dam age to the device. this is a stress o nly rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. note: 1. ja is measured with the component mounted on a low effective ther mal conductivity test board in free air. see tech brief tb379 fo r details. electrical specifications test conditions: v cc = 4.5v to 5.5v; unless otherwise specified. typicals are at v cc = 5v, t a = 25 o c, note 2 parameter symbol test conditions temp ( o c) min typ max units dc characteristics driver differential v out (no load) v od1 full - - v cc v driver differential v out (with load) v od2 r = 50 ? (rs-422), (figure 1) full 2 3 - v r = 27 ? (rs-485), (figure 1) full 1.5 2.3 5 v change in magnitude of driver differential v out for complementary output states ? v od r = 27 ? or 50 ? , (figure 1) full - 0.01 0.2 v driver common-mode v out v oc r = 27 ? or 50 ? , (figure 1) full - - 3 v change in magnitude of driver common-mode v out for complementary output states ? v oc r = 27 ? or 50 ? , (figure 1) full - 0.01 0.2 v logic input high voltage v ih de, di, re full 2 - - v logic input low voltage v il de, di, re full - - 0.8 v logic input current i in1 de, di, re full -25 - 25 a input current (a, b), (note 5) i in2 de = 0v, v cc = 0v or 4.5 to 5.5v v in = 12v full - - 1 ma v in = -7v full - - -0.8 ma receiver differential threshold voltage v th -7v v cm 12v full -0.2 - 0.2 v receiver input hysteresis ? v th v cm = 0v 25 - 70 - mv receiver output high voltage v oh i o = -4ma, v id = 200mv full 3.5 4 - v receiver output low voltage v ol i o = -4ma, v id = 200mv full - 0.1 0.4 v three-state (high impedance) receiver output current i ozr 0.4v v o 2.4v full - - 1 a receiver input resistance r in -7v v cm 12v full 12 25 - k ? no-load supply current, (note 3) i cc di, re = 0v or v cc de = v cc full - 590 900 a de = 0v full - 360 500 a driver short-circuit current, v o = high or low i osd1 de = v cc , -7v v y or v z 12v, (note 4) full 35 - 250 ma receiver short-circuit current i osr 0v v o v cc full 7 - 85 ma isl4485e
4 switching characteristics driver input to output delay t plh , t phl r diff = 54 ? , c l = 100pf, (figure 2) full 15 30 50 ns driver output skew t skew r diff = 54 ? , c l = 100pf, (figure 2) full - 1.3 5 ns driver differential rise or fall time t r , t f r diff = 54 ? , c l = 100pf, (figure 2) full 3 11 25 ns driver enable to output high t zh c l = 100pf, sw = gnd, (figure 3) full - 17 30 ns driver enable to output low t zl c l = 100pf, sw = v cc , (figure 3) full - 14 30 ns driver disable from output high t hz c l = 15pf, sw = gnd, (figure 3) full - 19 30 ns driver disable from output low t lz c l = 15pf, sw = v cc , (figure 3) full - 13 30 ns driver maximum data rate f maxd figure 4, ? v od ? 1.5v full 20 - - mbps receiver input to output delay t plh , t phl figure 5 full 20 40 70 ns receiver skew | t plh - t phl |t skd figure 5 full - 3 10 ns receiver enable to output high t zh c l = 15pf, sw = gnd, (figure 6) full - 9 25 ns receiver enable to output low t zl c l = 15pf, sw = v cc , (figure 6) full - 9 25 ns receiver disable from output high t hz c l = 15pf, sw = gnd, (figure 6) full - 9 25 ns receiver disable from output low t lz c l = 15pf, sw = v cc , (figure 6) full - 9 25 ns receiver maximum data rate f maxr c l = 15pf, v id 1.5v full 20 - - mbps esd performance rs-485 pins (a/y, b/z) human body model 25 - 15 - kv all other pins 25 - > 7-kv note: 2. all currents into device pins are positive; all currents out of device pins are negative. all voltages are referenced to devi ce ground unless otherwise specified. 3. supply current specification is va lid for loaded drivers when de = 0v. 4. applies to peak current. see ?typical pe rformance curves? for more information. 5. devices meeting these limits are denoted as ?single unit load (1 ul)? transceivers. the rs-485 standard allows up to 32 unit loads on the bus. test circuits and waveforms figure 1. driver v od and v oc electrical specifications test conditions: v cc = 4.5v to 5.5v; unless otherwise specified. typicals are at v cc = 5v, t a = 25 o c, note 2 (continued) parameter symbol test conditions temp ( o c) min typ max units d de di v cc v od v oc r r z y isl4485e
5 figure 2a. test circuit figure 2b. measurement points figure 2. driver propagation delay and differential transition times figure 3a. test circuit figure 3b. measurement points figure 3. driver enable and disable times test circuits and waveforms (continued) d de di v cc signal generator c l = 100pf r diff z y c l = 100pf out (y) 3v 0v t plh 1.5v 1.5v v oh v ol 50% 50% t phl out (z) t phl v oh v ol 50% 50% t plh diff out (y - z) t r +v od -v od 90% 90% t f 10% 10% di skew = |crossing pt. of y & z - crossing pt. of y & z | d de di c l 500 ? z y v cc gnd sw parameter output re di sw c l (pf) t hz y/z x 1/0 gnd 15 t lz y/z x 0/1 v cc 15 t zh y/z x 1/0 gnd 100 t zl y/z x 0/1 v cc 100 signal generator out (y, z) 3v 0v 1.5v 1.5v v oh 0v 2.3v v oh - 0.5v t hz out (y, z) v cc v ol 2.3v v ol + 0.5v t lz de output high output low t zl t zh isl4485e
6 figure 4a. test circuit figure 4b. measurement points figure 4. driver data rate figure 5a. test circuit figure 5b. measurement points figure 5. receiver propagation delay figure 6a. test circuit figure 6b. measurement points figure 6. receiver enable and disable times test circuits and waveforms (continued) d de di v cc signal generator z y c d = 200pf v od + - 60 ? 3v 0v diff out (y - z) +v od -v od di 0v signal generator r ro re a b +1.5v 15pf ro 3v 0v t plh 1.5v 1.5v v cc 0v 50% 50% t phl a 1k ? v cc gnd sw parameter de a sw t hz 0 +1.5v gnd t lz 0-1.5vv cc t zh 0 +1.5v gnd t zl 0-1.5vv cc signal generator r ro re a b 15pf ro 3v 0v 1.5v 1.5v v oh 0v 1.5v v oh - 0.5v t hz ro v cc v ol 1.5v v ol + 0.5v t lz re output high output low t zl t zh isl4485e
7 application information rs-485 and rs-422 are diff erential (balanced) data transmission standards for use in long haul or noisy environments. rs-422 is a su bset of rs-485, so rs-485 transceivers are also rs-422 compliant. rs-422 is a point- to-multipoint (multidrop) stan dard, which allows only one driver and up to 10 (assuming one unit load devices) receivers on each bus. rs-485 is a true multipoint standard, which allows up to 32 one unit load devices (any combination of drivers and receivers) on each bus. to allow for multipoint operation, the rs-485 spec requires that drivers must handle bus content ion without sustaining any damage. another important advantage of rs-485 is the extended common mode range (cmr), which specifies that the driver outputs and receiver inputs withstand signals that range from +12v to -7v. rs-422 and rs-485 are intended for runs as long as 4000?, so the wide cmr is necessary to handle ground potential differences, as well as voltages induced in the cable by external fields. receiver features the isl4485e utilizes a differential input receiver for maximum noise immunity and common mode rejection. input sensitivity is 200mv, as required by the rs-422 and rs-485 specifications. receiver input impedance surpasses the rs-422 spec of 4k ? , and meets the rs-485 ?unit load? requirement of 12k ? minimum. receiver inputs function wit h common mode voltages as great as 7v outside the power supplies (i.e., +12v and -7v), making them ideal for long networks where induced voltages are a realistic concern. the receiver includes a ?fail-sa fe if open? function that guarantees a high level receiver output if the receiver inputs are unconnected (floating). the ou tput is tri-statable via the active low re input, and the receiver easily meets the 20mbps data rate. driver features the rs-485/422 driver is a differential output device that delivers at least 1.5v across a 54 ? load (rs-485), and at least 2v across a 100 ? load (rs-422). the isl4485e driver features low propagation delay skew to maximize bit width, and to minimize emi, and the outputs are tri-statable via the active high de input. outputs of isl4485e drivers are not slew rate limited, so faster output transition times allow data rates up to 20mbps. data rate, cables, and terminations twisted pair is the cable of choice for rs-485/422 networks. twisted pair cables tend to pick up noise and other electromagnetically induce d voltages as common mode signals, which are effectively rejected by the differential receivers in these ics. rs-485/422 are intended for network lengths up to 4000', but the maximum transmission length decreases as the data rate increases. according to guidelines in the rs-422 specification, a 20mbps network should be limited to less than 50' of 24 awg twisted pair. nevertheless, the isl4485e's large differential vo ltage swing, fast transition times, and high drive-current output stages allow operation at 20mbps in rs-485/422 networ ks as long as 450'. figure 7 details isl4485e operation at 20 mbps driving 300' of cat 5 cable terminated in 120 ? at the driver and the receiver (i.e., double terminated). the acceptanc e criteria for this test was the ability of the driver to delive r a 1.5v differential signal to the receiver at the end of the cable (i.e., |a-b| 1.5v). if a more liberal acceptance criteria is used, the distance can be further extended. for example, figure 8 illustrates the performance in the same configuration, but with a cable length of 450', and an acceptanc e criteria of no more than 6db attenuation across the cable (i.e., |a-b| = |y-z|/2). driver differential output volt age decreases with increasing differential load capacitance, so maintaining a 1.5v differential output requires a da ta rate reduction, as shown in figure 9. to minimize reflections, proper termination is imperative when using this 20mbps device. in point-to-point, or point-to- multipoint (single driver on bus) networks, the main cable should be terminated in its characteristic impedance (typically 120 ? ) at the end farthest fr om the driver. in multi- receiver applications, stubs connecting receivers to the main cable should be kept as short as possible (preferably less than 12 inches). multipoint (mu lti-driver) systems require that the main cable be terminated in its characteristic impedance at both ends. again, stubs c onnecting a transceiver to the main cable should be kept as short as possible. built-in driver overload protection as stated previously, the rs-485 spec requires that drivers survive worst case bus c ontentions undamaged. the isl4485e device meets this requi rement via driver output short circuit current limits, and on-chip thermal shutdown circuitry. the driver output stages inco rporate short circuit current limiting circuitry which ensures that the output current never exceeds the rs-485 spec, even at the common mode voltage range extremes. additi onally, these devices utilize a foldback circuit which reduces the short circuit current, and thus the power dissipation, w henever the contending voltage exceeds either supply. in the event of a major short circuit condition, this device also includes a thermal shutdow n feature that disables the drivers whenever the die temperature becomes excessive. this eliminates the power dissipation, allowing the die to cool. the drivers automatically reenable after the die isl4485e
8 temperature drops about 15 degrees. if the contention persists, the thermal shutdown / reenable cycle repeats until the fault is cleared. receivers stay operational during thermal shutdown. esd protection all pins on these interface devices include class 3 human body model (hbm) esd protection structures, but the rs-485 pins (driver outputs a nd receiver inputs) incorporate advanced structures allowing them to survive esd events in excess of 15kv hbm. the rs-485 pins are particularly vulnerable to esd damage because they typically connect to an exposed port on the exterior of the finished product. simply touching the port pins, or connecting a cable, can cause an esd event that might destroy unprotected ics. these new esd structures prot ect the device whether or not it is powered up, protect without allowing any latchup mechanism to activate, and without degrading the rs-485 common mode range of -7v to +12v. this built-in esd protection eliminates the ne ed for board level protection structures (e.g., transient suppression diodes), and the associated, undesirable capacitive load they present. human body model testing as the name implies, this test method emulates the esd event delivered to an ic during human handling. the tester delivers the charge stored on a 100pf capacitor through a 1.5k ? current limiting resistor in to the pin under test. the hbm method determines an ics ability to withstand the esd events typically present during handling and manufacturing. the rs-485 pin survivability on this high esd device has been characterized to be in excess of 15kv, for discharges to gnd. typical performance curves v cc = 5v, t a = 25 o c; unless otherwise specified figure 7. driver and receiver waveforms driving 300 feet of cable (double terminated) figure 8. driver and receiver waveforms driving 450 feet of cable (double terminated) figure 9. data rate vs differential capacitance figure 10. supply current vs temperature time (20ns/div) -3 receiver output (v) 1.5 3 -1.5 0 a - b 0 5 receiver input (v) 0 5 driver input (v) di ro driver+cable delay (~450ns) time (20ns/div) -3 receiver output (v) 1.5 3 -1.5 0 a - b 0 5 receiver input (v) 0 5 driver input (v) di ro driver+cable delay (~650ns) differential capacitance (pf) data rate (mbps) 500 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 0 5 10 15 20 25 30 r diff = 54 ? -40 0 50 85 temperature ( o c) i cc ( a) -25 25 75 300 350 400 450 500 550 600 650 de = v cc , re = x de = gnd, re = x isl4485e
9 figure 11. driver output current vs differential output voltage figure 12. driver differen tial output voltage vs temperature figure 13. driver propagation delay vs temperature figure 14. driver skew vs temperature typical performance curves v cc = 5v, t a = 25 o c; unless otherwise specified (continued) differential output voltage (v) driver output current (ma) 012345 0 10 20 30 40 50 60 70 80 90 -40 0 50 85 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 temperature ( o c) differential output voltage (v) -25 25 75 r diff = 54 ? r diff = 100 ? -40 0 50 85 temperature ( o c) -25 25 75 25 30 35 40 t plhy t phly t phlz propagation delay (ns) t plhz 25 -40 0 50 85 temperature ( o c) skew (ns) -25 25 75 1 1.5 2 2.5 3 t plhy - t phlz t phly - t plhz crossing pt. of y & z - crossing pt. of y & z isl4485e
10 die characteristics substrate potential (powered up): gnd transistor count: 518 process: si gate cmos figure 15. driver and receiver waveforms, low to high figure 16. driver and receiver waveforms, high to low figure 17. driver output current vs short circuit voltage typical performance curves v cc = 5v, t a = 25 o c; unless otherwise specified (continued) time (10ns/div) 0 receiver output (v) 3 4 1 2 r diff = 54 ? , c l = 100pf di a / y ro 0 5 driver output (v) 0 5 driver input (v) b / z time (10ns/div) 0 di ro receiver output (v) 3 4 1 2 driver output (v) 0 5 0 5 driver input (v) r diff = 54 ? , c l = 100pf b / z a / y output voltage (v) -7 -6 -4 -2 0 2 4 6 8 10 12 output current (ma) -60 -40 -20 0 20 40 60 80 100 120 140 160 -80 -100 -120 y or z = high y or z = low isl4485e
11 all intersil u.s. products are manufactured, asse mbled and tested utilizing iso9000 quality systems. intersil corporation?s quality ce rtifications can be viewed at www.intersil.com/design/quality intersil products are sold by description only. intersil corporation reserves the right to make changes in circuit design, soft ware and/or specifications at any time without notice. accordingly, the reader is cautioned to verify that da ta sheets are current before placing orders. information furnishe d by intersil is believed to be accurate and reliable. however, no responsibility is assumed by intersil or its subsidiaries for its use; nor for any infringements of paten ts or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of intersil or its subsidiari es. for information regarding intersil corporation and its products, see www.intersil.com small outline plast ic packages (soic) index area e d n 123 -b- 0.25(0.010) c a m bs e -a- l b m -c- a1 a seating plane 0.10(0.004) h x 45 o c h 0.25(0.010) b m m notes: 1. symbols are defined in the ?mo series symbol list? in section 2.2 of publication number 95. 2. dimensioning and tolerancing per ansi y14.5m - 1982. 3. dimension ?d? does not include mold flash, protrusions or gate burrs. mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. 4. dimension ?e? does not include in terlead flash or protrusions. inter- lead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. 5. the chamfer on the body is optional. if it is not present, a visual index feature must be located within the crosshatched area. 6. ?l? is the length of terminal for soldering to a substrate. 7. ?n? is the number of terminal positions. 8. terminal numbers are shown for reference only. 9. the lead width ?b?, as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch). 10. controlling dimension: millimete r. converted inch dimensions are not necessarily exact. m8.15 (jedec ms-012-aa issue c) 8 lead narrow body small outline plastic package symbol inches millimeters notes min max min max a 0.0532 0.0688 1.35 1.75 - a1 0.0040 0.0098 0.10 0.25 - b 0.013 0.020 0.33 0.51 9 c 0.0075 0.0098 0.19 0.25 - d 0.1890 0.1968 4.80 5.00 3 e 0.1497 0.1574 3.80 4.00 4 e 0.050 bsc 1.27 bsc - h 0.2284 0.2440 5.80 6.20 - h 0.0099 0.0196 0.25 0.50 5 l 0.016 0.050 0.40 1.27 6 n8 87 0 o 8 o 0 o 8 o - rev. 0 12/93 isl4485e

▲Up To Search▲

Price & Availability of ISL4485EIB-T

	To Download ISL4485EIB-T Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .