1 l tc1320 d u e s c r ip t i o s f ea t u re appl e t alk t ransceiver n single chip provides complete localtalk /appletalk port n low power: i cc = 1.2ma typ n shutdown pin reduces i cc to 30 m a typ n drivers maintain high impedance in three-state or with power off n 30ns driver propagation delay typ n 5ns driver skew typ n thermal shutdown protection n drivers are short-circuit protected the ltc1320 is an rs422/rs562 line transceiver de- signed to operate on localtalk networks. it provides one differential rs422 driver, one single-ended rs562 driver, two single-ended rs562 receivers, and one differential rs422 receiver. the ltc1320 draws only 1.2ma quies- cent current when active and 30 m a in shutdown, making it ideal for use in battery-powered devices and other systems where power consumption is a primary concern. the ltc1320 drivers are specified to drive 2v into 100 w . additionally, the driver outputs three-state when disabled, during shutdown, or when the power is off; they maintain high impedance even with output common-mode volt- ages beyond the power supply rails. both the driver outputs and receiver inputs are protected against esd damage to beyond 5kv. the ltc1320 is available in the 18-pin sol package. u s a o pp l ic at i n localtalk peripherals n notebook/palmtop computers n battery-powered systems typical localtalk connection output waveforms 2v/div 2v/div 5v/div 5v/div data in signals on line data out (remote receiver) 50ns/div u a o pp l ic at i ty p i ca l 17 22 w 100pf 22 w 16 22 w 22 w 11 10 1 3 8 18 5v 5 v 91 4 ltc1320 #1 ltc1320 ta01 100pf 120 w localtalk transformer data in 5 4 22 w 22 w 22 w 100pf 22 w 100pf 1k 1k data out shutdown tx enable rx enable appletalk and localtalk are registered trademarks of apple computer, inc. for information purposes only obsolete: contact linear technology for potential replacement
2 ltc1320 a u g w a w u w a r b s o lu t exi t i s supply voltage (v dd ) ................................................ 7v supply voltage (v ss ) .............................................. C 7v input voltage (logic inputs) ......... C 0.3v to v dd + 0.3v input voltage (receiver inputs) ............................ 15v driver output voltage (forced) ............................. 15v output short-circuit duration ......................... indefinite operating temperature range ................... 0 c ot 70 c storage temperature range ................ C 65 c to 150 c lead temperature (soldering, 10 sec)................ 300 c wu u package / o rder i for atio order part number ltc1320cs symbol parameter conditions min typ max units v od differential driver output voltage no load l 8.0 v r l = 100 w (figure 1) l 2.0 v change in magnitude of driver r l = 100 w (figure 1) 0.2 v differential output voltage v oc driver common-mode output voltage r l = 100 w (figure 1) 3 v output common-mode range sd = 5v or power off l 10 v single-ended driver output voltage no load l 4.0 v r l = 400 w l 3.4 v input high voltage all logic input pins l 2.0 v input low voltage all logic input pins l 0.8 v input current all logic input pins l 1 20 m a three-state output current sd = 5v or power off, C 10v < v o < 10v l 2 100 m a driver short-circuit current C 5v < v o < 5v l 35 350 500 ma receiver input resistance C 7v < v in < 7v l 12 k w v oh receiver output high voltage i o = C 4ma l 3.5 v v ol receiver output low voltage i o = 4ma l 0.4 v receiver output short-circuit current 0v < v o < 5v l 785ma receiver output three-state current 0v < v o < 5v l 2 100 m a differential receiver threshold voltage C 7v < v cm < 7v l C 200 200 mv differential receiver input hysteresis C 7v < v cm < 7v 70 mv single-ended receiver input low voltage l 0.8 v single-ended receiver input high voltage l 2v i dd supply current no load, sd = 0v l 1.2 3.0 ma no load, sd = 5v l 30 350 m a i ss supply current no load, sd = 5v l 2 350 m a dc electrical characteristics v s = 5v 5%, t a = 0 c to 70 c (notes 2, 3) 1
2
3
4
5
6
7
8
9 top view 18
17
16
15
14
13
12
11
10
txd
txi
txden
sd
rxen
rxo
rxo
rxdo
gnd v dd
txd
txd +
txo
v ss
rxi
rxi
rxd
rxd + s package
18-lead plastic sol ltc1320 ?po01 t jmax = 150 c, q ja = 100 c/w consult factory for industrial and military grade parts.
3 ltc1320 switchi g characteristics u symbol parameter conditions min typ max units t plh, hl differential driver propagation delay r l = 100 w , c l = 100pf (figures 2, 8) l 40 120 ns t skew differential driver output to output r l = 100 w , c l = 100pf (figures 2, 8) l 10 50 ns t r, f differential driver rise/fall time r l = 100 w , c l = 100pf (figures 2, 8) l 15 80 ns t enh, l driver enable to output active c l = 100pf (figures 3, 4, 10) l 50 150 ns t h, ldis driver output active to disable c l = 15pf (figures 3, 4, 10) l 50 150 ns t plh, hl single-ended driver propagation delay r l = 450 w , c l = 100pf (figures 5, 11) l 40 120 ns t r, f single-ended driver rise/fall time r l = 450 w , c l = 100pf (figures 5, 12) l 15 80 ns t plh, hl receiver propagation delay c l = 15pf (figures 13, 14) l 60 160 ns t enh, l receiver enable to output active c l = 100pf (figures 6, 7, 15) l 30 100 ns t h, ldis receiver output active to disable c l = 15pf (figures 6, 7, 15) l 30 100 ns v s = 5v 5%, t a = 0 c to 70 c (notes 2, 3) note 2: all currents into device pins are positive; all currents out of device pins are negative. all voltages are referenced to ground unless otherwise specified. note 3: all typicals are given at v s = 5v, t a = 25 c. the l denotes specifications which apply over the full operating temperature range. note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. differential output swing vs load current output swing vs load current output current (ma) 0 differential output swing (v) 6 8 10 80 ltc1320 ?g02 4 2 0 20 40 60 100 supply current vs temperature cc hara terist ics uw a t y p i ca lper f o r c e pi fu ctio s u uu txd (pin 1): rs422 differential driver input (ttl compat- ible). txi (pin 2): rs562 single-ended driver input (ttl com- patible. txden (pin 3): rs422 differential driver output enable (ttl compatible). a high level on this pin forces the rs422 driver into three-state; a low level enables the driver. this input does not affect the rs562 single-ended driver. sd (pin 4): shutdown input (ttl compatible). when this pin is high, the chip is shut down: all driver outputs three- state and the supply current drops to 30 m a. a low on this pin allows normal operation. output current (ma) 0 output swing (v) 1 3 5 80 ltc1320 ?g01 ? ? ? 20 40 60 100 0 2 4 ? ? output high output low temperature (?) 0 0 supply current (ma) 0.004 1.0 1.1 1.2 10 20 30 40 ltc1320 ?g03 50 60 70 0.002 i dd i ss
4 ltc1320 rxen (pin 5): receiver enable (ttl compatible). a high level on this pin disables the receivers and three-states the logic outputs; a low level allows normal operation. to prevent erratic behavior at the receiver outputs during shutdown, rxen should be pulled high along with sd. rxo (pin 6): inverting rs562 single-ended receiver output. rxo (pin 7): noninverting rs562 single-ended receiver output. rxdo (pin 8): rs422 differential receiver output. gnd (pin 9): ground pin. rxd + (pin 10): rs422 differential receiver noninverting input. when this pin is 3 200mv above rxd C , rxdo will be high; when this pin is 3 200mv below rxd C , rxdo will be low. rxd C (pin 11): rs422 differential receiver inverting input. pi fu ctio s u uu test circuits rxi (pin 12): noninverting rs562 receiver input. this input controls the rxo output; it has no effect on the rxo output. rxi (pin 13): inverting rs562 receiver input. this input controls the rxo output; it has no effect on the rxo output. v ss (pin 14): negative supply. C 4.75 3 v ss 3 C 5.25v. the voltage on this pin must never exceed ground on power up or power-down. txo (pin 15): rs562 single-ended driver output. txd + (pin 16): rs422 differential driver noninverting output. txd C (pin 17): rs422 differential driver inverting output. v dd (pin 18): positive supply. 4.75v v dd 5.25v. output
under test c l 500 w v dd v ss ltc1320 ?f03 figure 3 r l c l1 c l2 txd ltc1320 ?tcf02 txd + txd figure 2 output
under test c l v ss ltc1320 ?f04 500 w figure 4 output
under test c l ltc1320 ?f07 500 w figure 7 r l c l ltc1320 ?f05 txo txi figure 5 output
under test c l 500 w v dd ltc1320 ?f06 figure 6 r l /2 r l /2 v oc v od txd + txd ltc1320 ?f01 + figure 1
5 ltc1320 switchi g wavefor s u w t phl 1.5v 3v 0v f = 1mhz: t r < 10ns: t f < 10ns 1.5v t plh v oh v ol 1.5v 1.5v t plh 1.5v 3v 0v rxi f = 1mhz: t r < 10ns: t f < 10ns 1.5v t phl v oh v ol rxo 1.5v 1.5v rxi rxo ltc1320 ?f13 figure 13 1.5v t enl 3v 0v 1.5v 5v v ol 1.5v v oh 0v t enh 1.5v 0.5v 0.5v t ldis f = 1mhz: t r 10ns: t f 10ns output normally low output normally high rxo, rxo, rxdo rxo, rxo, rxdo ltc1320 ?f15 t hdis rxen figure 15 1.5v t enl 3v 0v txden 0v 5v v ol txd + , txd 0v v oh txd + , txd ?v t enh 1.5v 0.5v 0.5v t hdis t ldis f = 1mhz: t r 10ns: t f 10ns output normally low output normally high ltc1320 ?f10 figure 10 t plh 1.5v 3v 0v txd f = 1mhz: t r < 10ns: t f < 10ns 1.5v t phl txd txd + v o t skew t skew 1/2 v o 1/2 v o ltc1320 ?f08 figure 8 t phl 1.5v 3v 0v txi f = 1mhz: t r < 10ns: t f < 10ns 1.5v t plh v oh v ol txo 0v 0v ltc1320 ?f11 figure 11 v o ? o 90% 10% t r t f 90% 10% v diff = v(txd + ) ?v(txd ) ltc1320 ?f09 figure 9 v oh v ol 90% 10% t r t f 90% 10% ltc1320 ?f12 figure 12 t phl 0v 2.5v 2.5v (rxd ) ?(rxd + ) f = 1mhz: t r < 10ns: t f < 10ns 0v t plh v oh v ol rxdo 1.5v 1.5v ltc1320 ?f14 figure 14
6 ltc1320 u s a o pp l ic at i wu u i for atio thermal shutdown protection the ltc1320 includes a thermal shutdown circuit which protects the part against prolonged shorts at the driver outputs. if any driver output is shorted to another output or to the power supply, the current will be initially limited to 450ma max. the die temperature will rise to about 150 c, at which point the thermal shutdown circuit turns off the driver outputs. when the die cools to about 130 c, the outputs re-enable. if the shorted condition still exists, the part will heat again and the cycle will repeat. when the short is removed, the part will return to normal operation. this oscillation occurs at about 10hz and prevents the part from being damaged by excessive power dissipation. power shutdown the power shutdown feature of the ltc1320 is designed primarily for battery-powered systems. when sd (pin 4) is forced high, the part enters shutdown mode. in shut- down, the supply current drops from 1.2ma to 30 m a typ. the driver outputs are three-stated and the power to the receivers is removed. the receiver outputs are not auto- matically three-stated in shutdown, and can toggle errone- ously due to feedthrough from the inputs. this can be prevented by pulling rxen high along with sd; this will three-state the receiver outputs and prevent the genera- tion of spurious data. supply bypassing the ltc1320 requires that both v dd and v ss are well bypassed; data errors can result from inadequate bypass- ing. bypass capacitor values of 0.1 m f to 1 m f from v dd to ground and from v ss to ground are adequate. lead lengths and trace lengths between the capacitors and the chip should be short to minimize lead inductance. u s a o pp l ic at i ty p i ca l single 5v supply rs422 to rs562/rs562 to rs422 converter 17 1 18 0.1 m f 5v 914 0.1 m f driver i/o ltc1320 ?ta03 16 2 15 3 13 4 12 5 11 6 10 7 8 ltc1320 + 100 m f ltc1046
lt1054
* + 8 5 + 2 4 10 m f 2 m f 3 logic i/o 5v *ltc1046 gives 300 m a quiescent
current when ltc1320 is shut down
lt1054 provides higher output drive 1n5817 15 11 18 0.1 m f 5v 914 ltc1320 ?ta04 6 10 13 8 16 2 17 12 3 7 4 1 ltc1320 0.1 m f 5 ?v rs562 out nc nc + rs422 out + rs562 in rs422 in txo txd + txd rxi rxo sd rxen txden rxd rxdo txi rxo txd rxd + rxi v dd v ss gnd
7 ltc1320 u s a o pp l ic at i ty p i ca l 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 circuits as described herein will not infringe on existing patent rights. 3 25k esd protection sol18 0392 note:
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. see note 0.447 ?0.463
(11.354 ?11.760) 15 14 13 12 11 10 16 9 1 23 4 5 6 78 0.394 ?0.419
(10.007 ?10.643) 17 18 0.037 ?0.045
(0.940 ?1.143) 0.004 ?0.012
(0.102 ?0.305) 0.093 ?0.104
(2.362 ?2.642) 0.050
(1.270)
typ 0.014 ?0.019
(0.356 ?0.482)
typ 0??8?typ see note 0.009 ?0.013
(0.229 ?0.330) 0.016 ?0.050
(0.406 ?1.270) 0.291 ?0.299
(7.391 ?7.595) 45 0.010 ?0.029
(0.254 ?0.737) 0.005
(0.127)
rad min s package 18-lead plastic sol switched negative supply package descriptio
u
17 1 18 0.1 m f 5v 914 ltc1320 ?ta06 ltc1320 *general semiconductor icte-22c or equivalent to outside world
protected against esd
damage to 25kv data
input/output 0.1 m f ?v 16 2 15 3 13 4 12 5 11 6 10 7 * * * * * * * txd txi sd rxo txd txd + txo rxi rxd rxd + rxi txden rxen rxo 8 rxdo gnd v ss v dd 17 1 18 0.1 m f 5v 914 driver i/o ltc1320 ?ta05 16 2 15 3 13 4 12 5 11 6 10 7 8 ltc1320 logic i/o *schottky diode prevents v ss from exceeding
gnd on power-up or power-down 1n5817* 0.1 m f ?v txd txi sd rxo rxdo txd txd + txo rxi rxd rxd + txden rxen rxo rxi
8 ltc1320 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7487 (408) 432-1900 l fax : (408) 434-0507 l telex : 499-3977 lt/gp 1192 10k rev 0 ? linear technology corporation 1992 u.s. area sales offices northeast region central region northwest region linear technology corporation linear technology corporation linear technology corporation one oxford valley chesapeake square 782 sycamore dr. 2300 e. lincoln hwy.,suite 306 229 mitchell court, suite a-25 milpitas, ca 95035 langhorne, pa 19047 addison, il 60101 phone: (408) 428-2050 phone: (215) 757-8578 phone: (708) 620-6910 fax: (408) 432-6331 fax: (215) 757-5631 fax: (708) 620-6977 southeast region southwest region linear technology corporation linear technology corporation 17060 dallas parkway 22141 ventura blvd. suite 208 suite 206 dallas, tx 75248 woodland hills, ca 91364 phone: (214) 733-3071 phone: (818) 703-0835 fax: (214) 380-5138 fax: (818) 703-0517 international sales offices france korea taiwan linear technology s.a.r.l. linear technology korea branch linear technology corporation immeuble "le quartz" namsong building, #505 rm. 801, no. 46, sec. 2 58 chemin de la justice itaewon-dong 260-199 chung shan n. rd. 92290 chatenay mallabry yongsan-ku, seoul taipei, taiwan, r.o.c. france korea phone: 886-2-521-7575 phone: 33-1-46316161 phone: 82-2-792-1617 fax: 886-2-562-2285 fax: 33-1-46314613 fax: 82-2-792-1619 germany singapore united kingdom linear techonolgy gmbh linear technology pte. ltd. linear technology (uk) ltd. untere hauptstr. 9 101 boon keng road the coliseum, riverside way d-8057 eching #02-15 kallang ind. estates camberley, surrey gu15 3yl germany singapore 1233 united kingdom phone: 49-89-319741-0 phone: 65-293-5322 phone: 44-276-677676 fax: 49-89-3194821 fax: 65-292-0398 fax: 44-276-64851 japan linear technology kk 5f yz building 4-4-12 iidabashi chiyoda-ku tokyo, 102 japan phone: 81-3-3237-7891 fax: 81-3-3237-8010 world headquarters linear technology corporation 1630 mccarthy blvd. milpitas, ca 95035-7487 phone: (408) 432-1900 fax: (408) 434-0507 10/92
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