1 ltc1385 1385fb 3.3v low power eia/tia-562 transceiver operates from a single 3.3v supply low supply current: i cc = 200 a i cc = 35 a in driver disable mode i cc = 0.2 a in shutdown mode esd protection over 10kv uses small capacitors: 0.1 f operates to 120kbaud output overvoltage does not force current back into supplies eia/tia-562 i/o lines can be forced to 25v without damage pin compatible with lt1180a available in 20-lead ssop,18-lead pdip and 18-lead so packages the ltc 1385 is an ultra-low power, 2-driver/2-receiver eia / tia-562 transceiver which operates from a single 3.3v supply. the charge pump requires only four space- saving 0.1 f capacitors. the transceiver operates in one of three modes: normal, driver disable or shutdown. in the normal mode, i cc is only 200 a in the unloaded condition. in the driver disable mode, the charge pump is turned off, the driver outputs are forced into three-state, both receivers are kept active, and i cc drops to 35 a. in the shutdown mode, everything is turned off and i cc drops to 0.2 a. the ltc1385 is fully compliant with all data rate and overvoltage eia / tia-562 specifications. the transceiver can operate up to 120kbaud with a 1000pf, 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 quiescent and shutdown supply current vs temperature 2-drivers/2-receivers with shutdown and driver disable temperature ( c) quiescent current ( a) 600 500 400 300 200 100 0 20 40 60 ltc1385 ?ta02 80 0 1.2 1.0 0.8 0.6 0.4 0.2 0 shutdown current ( a) quiescent current shutdown current test condition: v cc = 3.3v ?0 features descriptio u applicatio s u typical applicatio u , ltc and lt are registered trademarks of linear technology corporation. ltc1385 ? ta01 0.1 f 0.1 f 0.1 f 0.1 f ltc1385 driver disable logic input logic input logic output logic output on/off 562 output v cc = 3.3v 562 output 562 input 562 input 5k 5k 300k v cc 300k v cc
2 ltc1385 1385fb supply voltage (v cc ) ................................................ 5v input voltage driver ....................................... 0.3v to v cc + 0.3v receiver ............................................... 25v to 25v digital input ............................... 0.3v to v cc + 0.3v output voltage driver .................................................... 25v to 25v receiver .................................... 0.3v to v cc + 0.3v short-circuit duration v + ................................................................... 30 sec v ................................................................... 30 sec driver output .............................................. indefinite receiver output .......................................... indefinite operating temperature range ltc1385c ............................................. 0 c to 70 c ltc1385i ........................................... 40 c to 85 c storage temperature range ................ 65 c to 150 c lead temperature (soldering, 10 sec)................. 300 c parameter conditions min typ max units any driver output voltage swing 3k to gnd positive 3.7 4.5 v negative 3.7 4.5 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 = v cc 5 a v in = 0v ?0 40 a output short-circuit current v out = 0v 10 ma output leakage current shutdown or driver disable or v cc = 0v (note 3,4), 10 500 a v out = 20v absolute axi u rati gs w ww u dc electrical characteristics the denotes specifications which apply over the full operating temperature range. v cc = 3.3v, c1 = c2 = c3 = c4 = 0.1 f, v on/off = v cc , driver disable = v cc , unless noted. ltc1385cg ltc1385ig order part number order part number ltc1385cn ltc1385csw ltc1385in ltc1385isw consult ltc marketing for parts specified with wider operating temperature ranges. t jmax = 125 c, ja = 135 c/w 1 2 3 4 5 6 7 8 9 10 top view g package 20-lead ssop 20 19 18 17 16 15 14 13 12 11 c1 + v + c1 c2 + c2 v tr2 out rx2 in nc on/off vcc gnd tr1 out rx1 in rx1 out tr1 in tr2 in rx2 out nc driver disable t jmax = 125 c, ja = 85 c/w 1 2 3 4 5 6 7 8 9 top view sw package 18-lead plastic so 18 17 16 15 14 13 12 11 10 c1 + v + c1 c2 + c2 v tr2 out rx2 in on/off v cc gnd tr1 out rx1 in rx1 out tr1 in tr2 in rx2 out n package 18-lead pdip driver disable package/order i for atio uu w
3 ltc1385 1385fb parameter conditions min typ max units 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 10v v in 10v 3 5 7 k ? output voltage output low, i out = 1.6ma (v cc = 3.3v) 0.2 0.4 v output high, i out = 160 a (v cc = 3.3v) 3.0 3.2 v output short-circuit current sinking current, v out = v cc ? 20 ma sourcing current, v out = 0v 2 7 ma output leakage current shutdown (note 4), 0v v out v cc 110 a power supply generator v + output voltage i out = 0ma 5.7 v i out = 5ma 5.5 v v output voltage i out = 0ma 5.3 v i out = 5ma 5.0 v supply rise time shutdown or driver disable to turn-on 0.2 ms power supply v cc supply current no load (note 2), 0 c to 70 c 0.2 0.5 ma no load (note 2), 40 c to 85 c 0.35 1.0 ma supply leakage current (v cc ) shutdown (note 4) 0.2 10 a driver disable (note 3) 35 50 a digital input threshold low 1.4 0.8 v digital input threshold high 2.0 1.4 v dc electrical characteristics ac characteristics parameter conditions min typ max units slew rate r l = 3k, c l = 51pf 8 30 v/ s r l = 3k, c l = 1000pf 3 5 v/ s driver propagation delay t hld (figure 1) 2 3.5 s (ttl to eia / tia-562) t lhd (figure 1) 2 3.5 s receiver propagation delay t hlr (figure 2) 0.3 0.8 s (eia / tia-562 to ttl) t lhr (figure 2) 0.2 0.8 s 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. note 3: measurements made in the driver disable mode are performed with v driver disable = gnd and v on/off = v cc . note 4: measurements made in the shutdown mode are performed with v on/off = 0v. the denotes specifications which apply over the full operating temperature range. v cc = 3.3v, c1 = c2 = c3 = c4 = 0.1 f, unless noted. the denotes specifications which apply over the full operating temperature range. v cc = 3.3v, c1 = c2 = c3 = c4 = 0.1 f, v on/off = v cc , driver disable = v cc , unless noted.
4 ltc1385 1385fb data rate (kbaud) 0 supply current (ma) 60 ltc1385 ?tpc03 10 5 20 40 80 0 20 15 100 120 140 v cc = 3.3v r l = 3k c l = 2500pf all drivers active supply current vs data rate temperature ( c) 0 0 supply current (ma) 0.5 1.5 2.0 2.5 40 4.5 ltc1385 ? tpc04 1.0 20 10 50 60 30 70 3.0 3.5 4.0 2 drivers loaded r l = 3k 1 driver loaded r l = 3k v cc supply current vs temperature temperature ( c) 0 ? driver output voltage (v) ? ? ? 0 5 2 20 40 50 ltc1385 ?tpc01 ? 3 4 1 10 30 60 70 output high v cc = 3.3v output low v cc = 3.3v all drivers with load r l = 3k driver output voltage vs temperature temperature (?c) 0 threshold voltage (v) 1.8 2.0 2.2 30 v th + v th 50 ltc1385 ? tpc02 1.6 1.4 10 20 40 60 70 1.2 1.0 receiver input thresholds vs temperature driver leakage in shutdown vs temperature temperature ( c) 0 leakage current ( a) 60 45 40 35 30 25 20 15 10 5 0 ltc1385 ? tpc05 20 70 10 30 40 50 v out = 20v v out = 20v driver short-circuit current vs temperature temperature ( c) 0 0 short-circuit current (ma) 2 6 8 10 20 18 ltc1385 ? tpc06 4 10 30 i sc i sc + 40 60 50 70 12 14 16 receiver short-circuit current vs temperature temperature ( c) 0 0 short-circuit current (ma) 5 15 20 25 20 45 ltc1385 ? tpc06 10 10 30 i sc 40 60 50 70 30 35 40 i sc + driver output waveforms receiver output waveform driver output r l = 3k c l = 1000pf input driver output r l = 3k ltc1385 ?tpc08 ltc1385 ?tpc09 receiver output c l = 51pf input typical perfor a ce characteristics uw
5 ltc1385 1385fb v cc : 3.3v input supply pin. this pin should be decoupled with a 0.1 f ceramic capacitor. gnd: ground pin. on/off: ttl/cmos compatible shutdown pin. a logic low puts the device in the shutdown mode independent of the driver disable pin. the supply current drops to 0.2 a and all driver and receiver outputs are forced into three-state. driver disable: ttl/cmos compatible input pin. with the on/off pin held high, a logic low forces the part into the driver disable mode with the charge pump turned off and the driver outputs forced into three-state. both receiv- ers remain active and the supply current drops to 35 a. a logic high forces the part into the normal mode. v + : positive supply output (eia/tia-562 drivers). v + ? 2v cc ?1v. this pin requires an external capacitor c = 0.1 f for charge storage. the capacitor may be tied to ground or v cc . with multiple devices, the v + and v pins may share a common capacitor. for a large number of devices, increasing the size of the shared common storage capacitors is recommended to reduce ripple. v : negative supply output (eia/tia-562 drivers). v ? (2v cc ?1.3v). 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 , and another from c2 + to c2 . to maintain charge pump efficiency, the capacitor? effective series resistance should be less than 2 ? . tr in: eia/tia-562 driver input pins. inputs are ttl/ cmos compatible. the inputs of unused drivers can be left unconnected since 300k input pull-up resistors to v cc are included on chip. to minimize power consumption, the internal driver pull-up resistors are disconnected from v cc in the shutdown mode. tr out: driver outputs at eia/tia-562 voltage levels. outputs are in a high impedance state when in the shut- down or driver disable mode 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 against esd 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. outputs are in a high impedance state when in the shutdown mode. 1.4v 0v v cc 0v v + v 0v driver input driver output 1.4v t hld t lhd 1385 f01 figure 1. driver propagation delay timing 0.8v v cc 0v 2.4v rx input rx output 1.3v t hlr 1.7v t lhr 1385 f02 v cc 0v figure 2. receiver propagation delay timing uu u pi fu ctio s switchi g ti e wavefor s uw w
6 ltc1385 1385fb driver timing test load receiver timing test load driver driver input 3k 51pf driver output 1385 f03 rx input 51pf rx output 1385 f04 rx esd test circuit test circuits 1385 f05 0.1 f 0.1 f 0.1 f 0.1 f ltc1385 driver disable 2 4 5 6 12 11 13 10 18 14 9 16 1 logic input logic input logic output logic output on/off 17 3 7 15 562 output rs562 line pins protected to 10kv v cc 562 output 562 input 562 input 5k s s s 5k s 300k v cc 300k v cc 8
7 ltc1385 1385fb 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 ta- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. u package descriptio n package 18-lead pdip (narrow .300 inch) (reference ltc dwg # 05-08-1510) g package 20-lead plastic ssop (5.3mm) (reference ltc dwg # 05-08-1640) g20 ssop 0204 0.09 ?0.25 (.0035 ?.010) 0 ?8 0.55 ?0.95 (.022 ?.037) 5.00 ?5.60** (.197 ?.221) 7.40 ?8.20 (.291 ?.323) 1234 5 6 7 8910 6.90 ?7.50* (.272 ?.295 ) 17 18 14 13 12 11 15 16 19 20 2.0 (.079) max 0.05 (.002) min 0.65 (.0256) bsc 0.22 ?0.38 (.009 ?.015) typ 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 ?5.7 7.8 ?8.2 recommended solder pad layout 1.25 0.12 n18 1002 .020 (0.508) min .120 (3.048) min .130 .005 (3.302 0.127) .065 (1.651) typ .045 ?.065 (1.143 ?1.651) .018 .003 (0.457 0.076) .005 (0.127) min .255 .015* (6.477 0.381) .900* (22.860) max 18 12 3 4 56 7 8 9 10 11 12 13 14 16 15 17 .008 ?.015 (0.203 ?0.381) .300 ?.325 (7.620 ?8.255) .325 +.035 ?015 +0.889 0.381 8.255 () 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
8 ltc1385 1385fb ? linear technology corporation 1994 lw/tp 08/04 1k rev b ? printed in usa linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7487 (408) 432-1900 fax : (408) 434-0507 www.linear.com u package descriptio sw package 18-lead plastic small outline (wide .300 inch) (reference ltc dwg # 05-08-1620) part number description comments lt1780/lt1781 5v, 2 driver, 2 receiver rs232 transceivers 15kv esd per iec 1000-4 ltc1327 3.3v, 3 driver, 5 receiver rs562 transceiver 300 a supply current, 0.2 a in shutdown ltc1348 3.3v to 5v, 3 driver, 5 receiver rs232 transceiver true rs232 on 3.3v, 5 receivers active in shutdown ltc1382 5v, 2 driver, 2 receiver rs232 transceiver 200 a supply current, 0.2 a in shutdown ltc1383 5v, 2 driver, 2 receiver rs232 transceiver 200 a supply current, narrow 16-pin so ltc1384 5v, 2 driver, 2 receiver rs232 transceiver 200 a supply current, 2 receivers active in shutdown ltc1386 3.3v, 2 driver, 2 receiver rs562 transceiver 200 a supply current, narrow 16-pin so related parts s18 (wide) 0502 note 3 .447 ?.463 (11.354 ?11.760) note 4 15 14 13 12 11 10 16 9 n/2 1 23 4 5 6 78 .394 ?.419 (10.007 ?10.643) 17 18 n .037 ?.045 (0.940 ?1.143) .004 ?.012 (0.102 ?0.305) .093 ?.104 (2.362 ?2.642) .050 (1.270) bsc .014 ?.019 (0.356 ?0.482) typ 0 ?8 typ note 3 .009 ?.013 (0.229 ?0.330) .016 ?.050 (0.406 ?1.270) .291 ?.299 (7.391 ?7.595) note 4 45 .010 ?.029 (0.254 ?0.737) .420 min .325 .005 recommended solder pad layout .045 .005 n 1 2 3 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)
|
