1 ltc1349 1349fa 5v low power rs232 3-driver/5-receiver transceiver with 2 receivers active in shutdown quiescent and shutdown supply current vs temperature low supply current: 300 a two receivers kept alive in shutdown esd protection over 10kv operates from a single 5v supply uses small capacitors: 0.1 f operates to 120k baud three-state outputs are high impedance when off output overvoltage does not force currentback into supplies rs232 i/o lines can be forced to 25v without damage pin compatible with lt1137a and lt1237 flowthrough architecture the ltc ? 1349 is a 3-driver/ 5-receiver rs232 transceiver with very low supply current. in the no load condition, thesupply current is only 300 a. the charge pump only requires four 0.1 f capacitors. in shutdown mode, two receivers are kept alive and thesupply current is 35 a. all rs232 outputs assume a high impedance state in shutdown and with the power off.the ltc1349 is fully compliant with all data rate and overvoltage rs232 specifications. the transceiver can operate up to 120k baud with a 2500pf, 3k ? load. both driver outputs and receiver inputs can be forced to 25v without damage, and can survive multiple 10kv esd strikes. notebook computers palmtop computers temperature ( c) quiescent current ( a) 12001000 800600 400 200 0 20 40 60 ltc1349 ? ta02 80 0 C40 6050 40 30 20 10 0 shutdown current ( a) quiescent current shutdown current test condition:v cc = 5v, all driver inputs tied to v cc . C20 100 3-drivers/5-receivers with shutdown ltc1349 ? ta01 v cc c1 0.1 f ltc1349 12 3 4 5 6 7 8 9 1011 12 13 14 driver 1 out rx1 in driver 2 out rx2 inrx3 in rx4 in driver 3 out rx5 in on/off nc 2827 26 25 24 23 22 21 20 19 18 17 16 15 c30.1 f driver 1 inrx1 out driver 2 in rx2 out rx3 out rx4 out driver 3 in rx5 out gnd nc nc v C v + c2 0.1 f c40.1 f features descriptio u applicatio s u typical applicatio u , ltc and lt are registered trademarks of linear technology corporation. downloaded from: http:///
2 ltc1349 1349fa ltc1349cgltc1349cnw ltc1349csw ltc1349ig ltc1349inw ltc1349isw order part number supply voltage (v cc ) ................................................ 6v input voltage driver ....................................... C 0.3v to v cc + 0.3v receiver ............................................... C 25v to 25v on/off pin .................................. C 0.3v to v cc + 0.3v output voltage driver .................................................... C 25v to 25v receiver .................................... C 0.3v to v cc + 0.3v short circuit duration v + ................................................................... 30 sec v C ................................................................... 30 sec driver output .............................................. indefinite receiver output .......................................... indefinite operating temperature range commercial (ltc1349c) ........................ 0 c to 70 c industrial (ltc1349i) ........................ C 40 c to 85 c storage temperature range ................ C 65 c to 150 c lead temperature (soldering, 10 sec)................. 300 c 12 3 4 5 6 7 8 9 1011 12 13 14 2827 26 25 24 23 22 21 20 19 18 17 16 15 v + v cc c1 + c1C dr1 out rx1 in dr2 out rx2 inrx3 in rx4 in dr3 out rx5 in on/off nc vCc2+ c2C dr1 in rx1 out dr2 in rx2 out rx3 out rx4 out dr3 in rx5 out gnd nc nc nw package 28-lead pdip top view sw package 28-lead plastic so g package 28-lead ssop t jmax = 125 c, ja = 96 c/w (g) t jmax = 125 c, ja = 56 c/w (nw) t jmax = 125 c, ja = 85 c/w (sw) consult ltc marketing for parts specified with wider operating temperatureranges. the denotes specifications which apply over the full operating temperature range. v cc = 5v, c1 = c2 = c3 = c4 = 0.1 f, unless noted. parameter conditions min typ max units any driver output voltage swing 3k to gnd positive 5.0 7.0 v negative C 5.0 C 6.5 v logic input voltage level input low level (v out = high) 1.4 0.8 v input high level (v out = low) 2.0 1.4 v logic input current v in = 5v 5 a v in = 0v C5 a output short-circuit current v out = 0v 9 12 ma output leakage current shutdown, v out = 20v (note 3) 10 500 a any receiver input voltage thresholds input low threshold 0.8 1.3 v input high threshold 1.7 2.4 v hysteresis 0.1 0.4 1.0 v input resistance C 10v v in 10v 3 5 7 k ? output voltage output low, i out = C 1.6ma (v cc = 5v) 0.2 0.4 v output high, i out = 160 a (v cc = 5v) 3.5 4.8 v output short-circuit current sinking current, v out = v cc C15 C40 ma output leakage current shutdown, 0 v out v cc (note 3) 11 0 a power supply generator v + output voltage i out = 0ma 8.0 v i out = 12ma 7.5 v v C output voltage i out = 0ma C 8.0 v i out = C 12ma C 7.0 v supply rise time shutdown to turn-on 0.2 ms absolute axi u rati gs w ww u package/order i for atio uu w dc electrical characteristics downloaded from: http:///
3 ltc1349 1349fa note 1: absolute maximum ratings are those values beyond which the life of the device may be impaired.note 2: supply current is measured with driver and receiver outputs unloaded. the denotes specifications which apply over the full operating temperature range. v cc = 5v, c1 = c2 = c3 = c4 = 0.1 f, unless noted. the denotes specifications which apply over the full operating temperature range. v cc = 5v, c1 = c2 = c3 = c4 = 0.1 f, unless noted. typical perfor a ce characteristics uw ac characteristics dc electrical characteristics parameter conditions min typ max units power supplyv cc supply current no load (all drivers v in = v cc )(note 2), 0 c t a 70 c 0.3 0.8 ma no load (all drivers v in = 0v)(note 2), 0 c t a 70 c 0.5 1.0 ma no load (all drivers v in = v cc )(note 2), 0 c t a 85 c 0.3 1.0 ma no load (all drivers v in = v cc )(note 2), C 40 c t a 0 c 0.3 1.5 ma no load (all drivers v in = 0v)(note 2), C 40 c t a 85 c 0.5 1.5 ma supply leakage current (v cc )s hutdown (note 3) 35 50 a on/off threshold low 1.4 0.8 v on/off threshold high 2.0 1.4 v parameter conditions min typ max units slew rate r l = 3k, c l = 51pf 8 30 v/ s r l = 3k, c l = 2500pf 3 5 v/ s driver propagation delay t hld (figure 1) 2 3.5 s (ttl to rs232) t lhd (figure 1) 2 3.5 s receiver propagation delay t hlr (figure 2) 0.3 0.8 s (rs232 to ttl) t lhr (figure 2) 0.2 0.8 s note 3: supply current and leakage current measurements in shutdown are performed with v on/off = 0v. driver output voltage supply current vs data rate receiver input thresholds temperature ( c) C40 C8 driver output voltage (v) C6 C2 0 2 40 10 ltc1349 ? tpc01 C4 0 100 4 6 8 C20 20 60 80 r l = 3k output high v cc = 5v v cc = 4.5v output low v cc = 4.5v v cc = 5v data rate (k baud) 0 supply current (ma) 150 4540 35 30 25 20 15 10 50 ltc1349 ? tpc03 50 175 25 75 100 125 v cc = 5v r l = 3k c l = 2500pf 3 drivers active temperature (?c) C40 threshold voltage (v) 1.8 2.0 2.2 20 60 ltc1349 ? tpc02 1.61.4 C20 0 40 80 100 1.21.0 v th v tl downloaded from: http:///
4 ltc1349 1349fa typical perfor a ce characteristics uw uu u pi fu ctio s with multiple devices, the v + and v C pins may be paral- leled into common capacitors. for large numbers of de-vices, increasing the size of the shared common storage capacitors is recommended to reduce ripple. v : negative supply output (rs232 drivers). v C ? 2v cc C 1.5v. this pin requires an external capacitor c = 0.1 f for charge storage.c1 + , c1 , c2 + , c2 : commutating capacitor inputs. these pins require two external capacitors c = 0.1 f: one from c1 + to c1 C , and another from c2 + to c2 C . to maintain charge pump efficiency, the capacitors effective seriesresistance should be less than 20 ? . driver output r l = 3k driver output r l = 3k c l = 2500pf input receiver output c l = 2500pf input ltc1349 ? tpc08 ltc1349 ? tpc09 v cc supply current driver short-circuit current driver leakage in shutdown temperature ( c) 0 supply current (ma) 60 2016 14 12 10 86 4 2 0 ltc1349 ? tpc04 20 70 10 30 40 50 3 drivers loaded r l = 3k 1 driver loaded r l = 3k temperature ( c) 0 leakage current ( a) 60 4540 35 30 25 20 15 10 50 ltc1349 ? tpc05 20 70 10 30 40 50 v out = C20v v out = 20v temperature ( c) C40 0 short-circuit current (ma) 4 8 10 12 40 20 ltc1349 ? tpc06 6 08 0 14 16 18 C20 60 20 100 i sc + i sc C receiver short-circuit current receiver output waveforms driver output waveforms temperature ( c) C40 10 short-circuit current (ma) 30 60 0 40 60 ltc1349 ? tpc07 20 50 40 C20 20 80 100 i sc C i sc + v cc : 5v input supply pin. supply current is typically 35 a in the shutdown mode. this pin should be decoupled witha 0.1 f ceramic capacitor. gnd: ground pin. on/off: ttl/cmos compatible shutdown pin. a logic low puts the device in shutdown mode, with receivers 4and 5 kept alive and the supply current equal to 35 a. all driver outputs and other receiver outputs are in highimpedance state. this pin can not float. v + : positive supply output (rs232 drivers). v + ? 2v cc C 1v. this pin requires an external capacitor c = 0.1 f for charge storage. the capacitor may be tied to ground or 5v. downloaded from: http:///
5 ltc1349 1349fa uu u pi fu ctio s driver in: rs232 driver input pins. inputs are ttl/ cmos compatible. inputs should not be allowed to float.tie unused inputs to v cc . driver out: driver outputs at rs232 voltage levels. outputs are in a high impedance state when in shutdownmode or v cc = 0v. the driver outputs are protected against esd to 10kv for human body model discharges. rx in: receiver inputs. these pins can be forced to 25v without damage. the receiver inputs are protected againstesd to 10kv for human body model discharges. each receiver provides 0.4v of hysteresis for noise immunity.rx out: receiver outputs with ttl/cmos voltage lev- els. receiver 1, 2 and 3 outputs are in a high impedancestate when in shutdown mode to allow data line sharing. receivers 4 and 5 are kept alive in shutdown. switchi g ti e wavefor s uw w figure 1. driver propagation delay timing figure 2. receiver propagation delay timing 1.4v 0v v cc 0v v + v C 0v driver input driver output 1.4v t hld t lhd ltc1349 ? f01 0.8v v cc 0v 2.4v rx input rx output 1.3v t hlr 1.7v t lhr ltc1349 ? f02 v cc 0v test circuits driver timing test load receiver timing test load driver driver input 3k 51pf driver output ltc1349 ? ta03 rx rx input 51pf rx output ltc1349 ? ta04 downloaded from: http:///
6 ltc1349 1349fa test circuits esd test circuit ltc1349 ? tc v cc c1 0.1 f ltc1349 12 3 4 5 6 7 8 9 1011 12 13 14 2827 26 25 24 23 22 21 20 19 18 17 16 15 c30.1 f v C v + c2 0.1 f c40.1 f rs232 line pins protected to 10kv driver 1 inrx1 out driver 2 in rx2 out rx3 out rx4 out driver 3 in rx5 out gnd nc nc driver 1 out rx1 in driver 2 out rx2 inrx3 in rx4 in driver 3 out rx5 in on/off nc downloaded from: http:///
7 ltc1349 1349fa u package descriptio nw28 1002 .505 C .560* (12.827 C 14.224) 1.467* (36.957) max 12 3 4 5 6 7 8 9 10 27 19 20 21 22 24 23 25 26 28 11 12 13 14 15 16 17 18 .008 C .015 (0.203 C 0.381) .625 +.035C.015 +0.889 C0.381 15.87 () .600 C .625 (15.240 C 15.875) .070 (1.778) typ .015 (0.381) min .120 (3.175) min .150 .005 (3.810 0.127) .018 .003 (0.457 0.076) .035 C .080 (0.889 C 2.032) .045 C .065 (1.143 C 1.651) note:1. dimensions are inches millimeters *these dimensions do not include mold flash or protrusions. mold flash or protrusions shall not exceed .010 inch (0.254mm) .100 (2.54) bsc information furnished by linear technology corporation is believed to be accurate and reliable.however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. g28 ssop 0802 0.09 C 0.25 (.0035 C .010) 0 C 8 0.55 C 0.95 (.022 C .037) 5.00 C 5.60** (.197 C .221) 7.40 C 8.20 (.291 C .323) 1234 5 6 7 8910 11 12 1413 9.90 C 10.50* (.390 C .413) 2526 22 21 20 19 18 17 16 15 2324 2728 2.0 (.079) 0.05 (.002) 0.65 (.0256) bsc 0.22 C 0.38 (.009 C .015) millimeters (inches) dimensions do not include mold flash. mold flash shall not exceed .152mm (.006") per side dimensions do not include interlead flash. interlead flash shall not exceed .254mm (.010") per side * ** note:1. controlling dimension: millimeters 2. dimensions are in 3. drawing not to scale 0.42 0.03 0.65 bsc 5.3 C 5.7 7.8 C 8.2 recommended solder pad layout 1.25 0.12 g package 28-lead plastic ssop (5.3mm) (reference ltc dwg # 05-08-1640) nw package 28-lead pdip (wide .600 inch) (reference ltc dwg # 05-08-1520) downloaded from: http:///
8 ltc1349 1349fa ? l inear technology corporation 1993 lw/tp 1102 1k rev a ? printed in usa s28 (wide) 0502 0 C 8 typ note 3 .009 C .013 (0.229 C 0.330) .016 C .050 (0.406 C 1.270) .291 C .299 (7.391 C 7.595) note 4 45 .010 C .029 (0.254 C 0.737) .037 C .045 (0.940 C 1.143) .004 C .012 (0.102 C 0.305) .093 C .104 (2.362 C 2.642) .050 (1.270) bsc .014 C .019 (0.356 C 0.482) typ note 3 .697 C .712 (17.70 C 18.08) note 4 1 23 4 5 6 78 .394 C .419 (10.007 C 10.643) 910 25 26 11 12 22 21 20 19 18 17 16 15 23 24 14 n/2 13 27 28 n .420 min .325 .005 recommended solder pad layout .045 .005 n 123 n/2 .050 bsc .030 .005 typ .005 (0.127) rad min inches (millimeters) note:1. dimensions in 2. drawing not to scale 3. pin 1 ident, notch on top and cavities on the bottom of packages are the manufacturing options. the part may be supplied with or without any of the options 4. these dimensions do not include mold flash or protrusions. mold flash or protrusions shall not exceed .006" (0.15mm) linear technology corporation 1 630 mccarthy blvd., milpitas, ca 95035-7487 (408) 432-1900 fax : (408) 434-0507 www . linear.com u package descriptio related parts part number description comments lt ? 1137a 5v, 3 driver, 5 receiver rs232 transceiver 15kv esd per iec 1000-4 ltc1327 3.3v, 3 driver, 5 receiver rs562 transceiver 300 a supply current, 0.2 a in shutdown ltc1337 5v, 3 driver, 5 receiver rs232 transceiver 300 a supply current, 1 a in shutdown ltc1348 3.3v to 5v, 3 driver, 5 receiver rs232 transceiver true rs232 on 3.3v, 5 receivers active in shutdown sw package 28-lead plastic small outline (wide .300 inch) (reference ltc dwg # 05-08-1620) downloaded from: http:///
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