View MAX3430EPD_6952697.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

general description the max3430 fault-protected rs-485 transceiver features 80v protection from overvoltage signal faults on commu- nication bus lines. each device contains one driver and one receiver, and the output pins can withstand faults, with respect to ground, of up to ?0v. even if the faults occur when the transceiver is active, shut down, or pow- ered off, the device will not be damaged. the max3430 operates from a 3.3v supply and features a slew-rate-lim- ited driver that minimizes emi and reduces reflections caused by improperly terminated cables, allowing error- free data transmission at data rates up to 250kbps. the max3430 has a 1/4-unit-load receiver input impedance allowing up to 128 transceivers on a single bus and fea- tures fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open. hot-swap circuitry eliminates false transitions on the data cable during circuit initialization or connection to a live backplane. short-circuit current limiting and ther- mal-shutdown circuitry protect the driver against exces- sive power dissipation. the max3430 is available in 8-pin so and 8-pin pdip packages, and is specified over commercial and indus- trial temperature ranges. applications rs-422/rs-485 communications lighting systems industrial-control local area networks profibus applications multimaster rs-485 networks features 80v fault protection 12kv esd protection +3.3v operation internal slew-rate limiting 250kbps data rate allows up to 128 transceivers on the bus -7v to +12v common-mode input voltage range true fail-safe inputs hot-swap input structure on de available in 8-pin so and pdip packages max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver ________________________________________________________________ maxim integrated products 1 pin configuration and typical operating circuit ordering information 1 2 3 4 8 5 v cc 0.1 f gnd di de re ro r d rt rt 7 6 d r de re di ro a b b a max3430 19-2756; rev 0; 1/03 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part temp range pin-package max3430cpd 0? to +70? 8 plastic dip max3430csd 0? to +70? 8 so MAX3430EPD -40? to +85? 8 plastic dip max3430esd -40? to +85? 8 so top view 1 2 3 4 8 7 6 5 v cc b a gnd di de re ro dip/so r d
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 2 _______________________________________________________________________________________ absolute maximum ratings dc electrical characteristics (v cc = +3.3v ?0%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25?.) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. (all voltages are referenced to gnd.) v cc ........................................................................................+5v re , de, di...................................................-0.3v to (v cc + 0.3v) driver output voltage (a, b) (note 1) ..................................?0v receiver input voltage (a, b) (note 1) ................................?0v ro ..............................................................-0.3v to (v cc + 0.3v) continuous power dissipation (t a = +70?) 8-pin so (derate 5.88mw/? above +70?)................471mw 8-pin plastic dip (derate 9.09mw/? above +70?) ...727mw operating temperature ranges max3430c_ _ .....................................................0? to +70? max3430e_ _ ..................................................-40? to +85? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? note 1: a, b must be terminated with 54 ? or 100 ? to guarantee ?0v fault protection. parameter symbol conditions min typ max units driver figure 1, r l = 100 ? 2.0 v cc differential driver output v od figure 1, r l = 54 ? 1.5 v cc v change in magnitude of differential output voltage ? v od figure 1, r l = 100 ? or 54 ? (note 2) 0.2 v driver common-mode output voltage v oc figure 1, r l = 100 ? or 54 ? v cc / 2 3 v change in magnitude of common-mode voltage ? v oc figure 1, r l = 100 ? or 54 ? (note 2) 0.2 v driver logic driver input high voltage v ih di 2.0 v driver input low voltage v il di 0.8 v driver input current i in di 1a 0 v out 12v (note 3) +250 driver short-circuit output current i osd -7v v out v cc (note 3) -250 ma (v cc - 1v) v out 12v (note 3) +10 driver short-circuit foldback output current i osdf -7v v out 1v (note 3) -10 ma receiver de = gnd, re = gnd, v in = +12v 250 de = gnd, re = gnd, v in = -7v -200 a input current (a, b) i a, b v in = -80v to +80v -6 +6 ma receiver differential threshold voltage v th -7v v cm 12v -200 -50 mv receiver input hysteresis ? v th v a + v b = 0 25 mv
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver _______________________________________________________________________________________ 3 dc electrical characteristics (continued) (v cc = +3.3v 10%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) parameter symbol conditions min typ max units receiver logic ro output high voltage v oh i o = -1.6ma v cc - 0.6 v ro output low voltage v ol i o = 1ma 0.4 v three-state output current at receiver i ozr 0 v o v cc 1a receiver input resistance r in -7v v cm 12v 48 k ? receiver output short-circuit current i osr 0 v ro v cc 95 ma control control input high voltage v cih de, re 2.0 v control input low voltage v cil de, re 0.8 v input current de current latch during first de rising edge 80 a input current re current latch during first re rising edge 80 a protection specifications (v cc = +3.3v 10%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) parameter symbol conditions min typ max units esd protection a, b human body model 12 kv supply current no load, re = 0, de = v cc , di = 0 or v cc 3.5 10 supply current i cc no load, re = v cc , de = v cc, di = 0 or v cc 3.0 8 ma supply current in shutdown mode i shdn re = v cc , de = 0 200 a
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 4 _______________________________________________________________________________________ driver switching characteristics (v cc = +3.3v 10%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) parameter symbol conditions min typ max units t dplh 700 1500 driver propagation delay t dphl figures 2 and 3, r l = 54 ? , c l = 50pf 700 1500 ns driver differential output rise or fall time t dr , t df figures 2 and 3, r l = 54 ? , c l = 50pf 250 1200 ns differential driver output skew, |t dplh - t dphl | t dskew figures 2 and 3, r l = 54 ? , c l = 50pf 150 200 ns maximum data rate 250 kbps driver enable to output low t dzl figure 4, c l = 50pf 5200 ns driver disable time from output low t dlz figure 4, c l = 50pf 1000 ns driver output enable time from shutdown t dzl ( shdn ) figure 4, c l = 50pf 8000 ns driver enable to output high t dzh figure 5, c l = 50pf 5200 ns driver disable time from output high t dhz figure 5, c l = 50pf 1000 ns driver output enable time from shutdown t dzh ( shdn ) figure 5, c l = 50pf 8000 ns driver time to shutdown t shdn 1000 ns receiver switching characteristics (v cc = +3.3v 10%, t a = t min to t max , unless otherwise noted. typical values are at v cc = +3.3v and t a = +25 c.) parameter symbol conditions min typ max units t rplh 120 receiver propagation delay t rphl figure 6, c l = 20pf, v id = 2v, v cm = 0 120 ns receiver output skew, |t rplh - t rphl | t skew figure 6, c l = 20pf 40 ns receiver enable to output low t rzl figure 7, r = 1k ? , c l = 20pf 80 ns receiver enable to output high t rzh figure 7, r = 1k ? , c l = 20pf 80 ns receiver disable time from low t rlz figure 7, r = 1k ? , c l = 20pf 80 ns receiver disable time form high t rhz figure 7, r = 1k ? , c l = 20pf 80 ns receiver output enable time from shutdown t rzh ( shnd ) , t rzl ( shnd ) figure 7, r = 1k ? , c l = 20pf 5000 ns receiver time to shutdown t shdn 1000 ns note 2: ? v od and ? v oc are the changes in v od and v oc , respectively, when the di input changes state. note 3: the short-circuit output current applies to peak current just prior to foldback current limiting; the short-circuit foldback ou tput current applies during current limiting to allow a recovery from bus contention.
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver _______________________________________________________________________________________ 5 0 1 3 2 4 5 -40 0 -20 20 40 60 80 supply current vs. temperature max3430 toc01 temperature ( c) supply current (ma) re = 0 de = v cc 0 75 50 25 150 125 100 175 200 -40 0 -20 20 40 60 80 shutdown current vs. temperature max3430 toc02 temperature ( c) shutdown current ( a) 0 4 12 8 16 20 0 1.0 0.5 1.5 2.0 2.5 3.0 3.5 output current vs. receiver output low voltage max3430 toc03 output low voltage (v) output current (ma) 0 3 12 9 6 15 18 0 1.0 0.5 1.5 2.0 2.5 3.0 3.5 output current vs. receiver output high voltage max3430 toc04 output high voltage (v) output current (ma) 3.00 3.10 3.05 3.20 3.15 3.25 3.30 -40 0 -20 20 40 60 80 receiver output high voltage vs. temperature max3430 toc05 temperature ( c) output high voltage (v) i o = -1.6ma 0 0.1 0.3 0.2 0.4 0.5 -40 0 -20 20 40 60 80 receiver output low voltage vs. temperature max3430 toc06 temperature ( c) output low voltage (v) i o = +1ma 0 20 80 60 40 100 120 0 1.0 0.5 1.5 2.0 2.5 3.0 3.5 driver output current vs. differential output voltage max3430 toc07 differential output voltage (v) output current (ma) 0 1.5 1.0 0.5 2.5 2.0 3.0 3.5 -40 0 -20 20 40 60 80 driver differential output voltage vs. temperature max3430 toc08 temperature ( c) differential output voltage (v) r l = 54 ? r l = 100 ? -3 -2 -1 0 1 2 3 -80 -40 -60 -20 0 20 40 60 80 a, b current vs. a, b voltage (to ground) max3430 toc09 a, b voltage (v) a, b current (ma) re = de = gnd typical operating characteristics (v cc = +3.3v, t a = +25 c, unless otherwise noted.)
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 6 _______________________________________________________________________________________ v od v oc 2 r l 2 r l a b figure 1. driver dc test load v o 3v r l c l c l di de a b figure 2. driver timing test circuit t dplh t dphl di 0 v cc a b 1/2 v o 1/2 v o v od = v (a) - v (b) t skew = |t dplh - t dphl | v cc /2 t dr t df v o 20% 80% 80% 20% v o figure 3. driver propagation delays v cc 50 ? r l = 500 ? c l 50pf generator d 0 or +3v out s1 v cc 0 0.25v v ol t dzl , t dzl(shdn) v om = (v ol + v cc )/2 v cc /2 v cc out de t dlz figure 4. driver enable and disable times (t dzl , t dlz , t dlz(shdn) ) v cc 0 0 v oh 0.25v 50 ? r l = 500 ? c l 50pf generator d 0 or +3v t dzh , t dzh(shdn) v om = (0 + v oh )/2 v cc /2 out out s1 de t dhz figure 5. driver enable and disable times (t dhz , t dzh , t dzh(shdn) ) test circuits/timing diagrams
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver _______________________________________________________________________________________ 7 c l 20pf r 0 a b v oh v ol 1.5v t rplh t rphl ro v id figure 6. receiver propagation delays 50 ? generator c l 20pf v cc 3v 0 v cc v ol r +1.5v -1.5v v id (v ol + v cc )/2 ro s1 s2 r 1k ? re 1.5v s1 closed s2 open s3 = -1.5v t rzl , t rzl (shdn) 3v 0 v oh 0 v oh /2 re s1 open s2 closed s3 = +1.5v t rzh , t rzh(shdn) 3v 0 v cc v ol 0.25v ro re 1.5v s1 closed s2 open s3 = -1.5v t rlz 3v 0 v oh 0 0.25v 1.5v ro re s1 open s2 closed s3 = +1.5v t rhz s3 ro ro figure 7. receiver enable and disable times test circuits/timing diagrams (continued)
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 8 _______________________________________________________________________________________ pin description pin name function 1 ro receiver output 2 re receiver output enable. ro is enabled when re is low; ro is high impedance when re is high. the device enters a low-power shutdown mode if re is high and de is low. 3de driver output enable. driving de high enables the driver outputs. pulling de low puts the driver outputs in a high-impedance state. if re is high and de is low, the device enters a low-power shutdown mode. if the driver outputs are enabled, the device functions as a line driver, and when they are high impedance it functions as a line receiver if re is low. 4di driver input. a logic low on di forces output a low and output b high, while a logic high on di forces output a high and output b low. 5 gnd ground 6 a noninverting receiver input/driver output 7 b inverting receiver input/driver output 8v cc positive supply, v cc = +3.3v 10%. bypass v cc to gnd with a 0.1f ceramic capacitor. function tables table 1. transmitting inputs outputs re de di b a mode x 1 1 0 1 normal x 1 0 1 0 normal 0 0 x high-z high-z normal 1 0 x high-z high-z shutdown table 2. receiving inputs outputs re de (a - b) ro mode 00 -50mv 1 normal 00 -200mv 0 normal 00 inputs open 1 normal 1 0 x high-z shutdown x = don? care. x = don? care.
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver _______________________________________________________________________________________ 9 detailed description driver the driver accepts a single-ended, logic-level input (di) and transfers it to a differential, rs-485 level output (a and b). driving de high enables the driver, while pulling de low places the driver outputs (a and b) into a high-impedance state. receiver the receiver accepts a differential, rs-485 level input (a and b), and transfers it to a single-ended, logic-level output (ro). pulling re low enables the receiver, while driving re high and de low places the receiver inputs (a and b) into a high-impedance state. low-power shutdown force de low and re high to shut down the max3430. a time delay of 1s prevents the device from accidentally entering shutdown due to logic skews when switching between transmit and receive modes. holding de low and re high for at least 1ms guarantees that the max3430 enters shutdown. in shutdown, the device consumes 100a supply current. 80v fault protection the driver outputs/receiver inputs of rs-485 devices in industrial network applications often experience voltage faults resulting from transients that exceed the -7v to +12v range specified in the eia/tia-485 standard. in these applications, ordinary rs-485 devices (typical absolute maximum ratings -8v to +12.5v) require costly external protection devices. to reduce system com- plexity and the need for external protection, the driver outputs/receiver inputs of the max3430 withstand volt- age faults of up to 80v with respect to ground without damage (see the absolute maximum ratings section, note 1). protection is guaranteed regardless of whether the device is active, shut down, or without power. true fail-safe the max3430 uses a -50mv to -200mv differential input threshold to ensure true fail-safe receiver inputs. this threshold guarantees the receiver outputs a logic high for shorted, open, or idle data lines. the -50mv to -200mv threshold complies with the 200mv threshold eia/tia-485 standard. 12kv esd protection as with all maxim devices, esd-protection structures are incorporated on all pins to protect against esd encountered during handling and assembly. the max3430 receiver inputs/driver outputs (a, b) have extra protection against static electricity found in nor- mal operation. maxim s engineers have developed state-of-the-art structures to protect these pins against 12kv esd without damage. after an esd event, the max3430 continues working without latchup. esd protection can be tested in several ways. the receiver inputs are characterized for protection up to 12kv using the human body model. esd test conditions esd performance depends on a number of conditions. contact maxim for a reliability report that documents test setup, methodology, and results. human body model figure 8a shows the human body model, and figure 8b shows the current waveform it generates when dis- charged into a low impedance. this model consists of a 100pf capacitor charged to the esd voltage of inter- est, which is then discharged into the device through a 1.5k ? resistor. driver output protection two mechanisms prevent excessive output current and power dissipation caused by faults or bus contention. the first, a foldback current limit on the driver output charge-current- limit resistor discharge resistance storage capacitor c s 100pf r c 1m ? r d 1.5k ? high- voltage dc source device under test figure 8a. human body esd test model i p 100% 90% 36.8% t rl time t dl current waveform peak-to-peak ringing (not drawn to scale) i r 10% 0 0 amperes figure 8b. human body model current waveform
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 10 ______________________________________________________________________________________ stage, provides immediate protection against short cir- cuits over the whole common-mode voltage range. the second, a thermal shutdown circuit, forces the driver outputs into a high-impedance state if the die tempera- ture exceeds +160 c. normal operation resumes when the die temperature cools by +140 c, resulting in a pulsed output during continuous short-circuit conditions. hot-swap capability hot-swap inputs inserting circuit boards into a hot, or powered backplane may cause voltage transients on de, re , and receiver inputs a and b that can lead to data errors. for example, upon initial circuit board insertion, the processor under- goes a power-up sequence. during this period, the high- impedance state of the output drivers makes them unable to drive the max3430 enable inputs to a defined logic level. meanwhile, leakage currents of up to 10a from the high-impedance output, or capacitively coupled noise from v cc or gnd, could cause an input to drift to an incorrect logic state. to prevent such a condition from occurring, the max3430 features hot-swap input circuitry on de to safeguard against unwanted driver activation during hot-swap situations. when v cc rises, an internal pulldown circuit holds de low for at least 10s, and until the current into de exceeds 200a. after the initial power-up sequence, the pulldown circuit becomes transparent, resetting the hot-swap tolerable input. hot-swap input circuitry at the driver enable input (de), there are two nmos devices, m1 and m2 ( figure 9). when v cc ramps from 0, an internal 15s timer turns on m2 and sets the sr latch, which also turns on m1. transistors m2, a 2ma current sink, and m1, a 100a current sink, pull de to gnd through a 5.6k ? resistor. m2 pulls de to the dis- abled state against an external parasitic capacitance up to 100pf that may drive de high. after 15s, the timer deactivates m2 while m1 remains on, holding de low against three-state leakage currents that may drive de high. m1 remains on until an external current source overcomes the required input current. at this time, the sr latch resets m1 and turns off. when m1 turns off, de reverts to a standard, high-impedance cmos input. whenever v cc drops below 1v, the input is reset. v cc timer timer de de (hot swap) 15 s 100 a m1 m2 5.6k ? 2ma figure 9. simplified structure of the driver enable pin (de) di ro de a b re ro ro ro di di di de de re de d d d r r r bb b a a a 120 ? 120 ? d r max3430 re re figure 10. typical rs-485 network
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver ______________________________________________________________________________________ 11 applications information 128 transceivers on the bus the standard rs-485 receiver input impedance is 12k ? (one-unit load), and a standard driver can drive up to 32-unit loads. the max3430 transceiver 1/4-unit-load receiver input impedance (48k ? ) allows up to 128 transceivers connected in parallel on one communica- tion line. connect any combination of these devices, and/or other rs-485 devices, for a maximum of 32 unit loads to the line. rs-485 applications the max3430 transceiver provides bidirectional data communications on multipoint bus transmission lines. figure 10 shows a typical network applications circuit. the rs-485 standard covers line lengths up to 4000ft. the signal line must be terminated at both ends in its characteristic impedance, and stub lengths off the main line kept as short as possible. chip information transistor count: 300 process: bicmos
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver 12 ______________________________________________________________________________________ package information (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline information, go to www.maxim-ic.com/packages .) soicn .eps package outline, .150" soic 1 1 21-0041 b rev. document control no. approval proprietary information title: top view front view max 0.010 0.069 0.019 0.157 0.010 inches 0.150 0.007 e c dim 0.014 0.004 b a1 min 0.053 a 0.19 3.80 4.00 0.25 millimeters 0.10 0.35 1.35 min 0.49 0.25 max 1.75 0.050 0.016 l 0.40 1.27 0.394 0.386 d d mindim d inches max 9.80 10.00 millimeters min max 16 ac 0.337 0.344 ab 8.75 8.55 14 0.189 0.197 aa 5.004.80 8 n ms012 n side view h 0.2440.228 5.80 6.20 e 0.050 bsc 1.27 bsc c h e e b a1 a d 0-8 l 1 variations:
max3430 80v fault-protected, fail-safe, 1/4-unit load, +3.3v rs-485 transceiver maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ____________________ 13 ? 2003 maxim integrated products printed usa is a registered trademark of maxim integrated products. package information (continued) (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline information, go to www.maxim-ic.com/packages .) pdipn.eps

▲Up To Search▲

Price & Availability of MAX3430EPD

	To Download MAX3430EPD Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .