functional block diagram 12k 12k 6k 6k ?n +in ssm2143 v out reference v+ v sense w w w w pin connections epoxy mini-dip (p suffix) and soic (s suffix) 1 2 3 45 6 7 8 ref ?n +in v op-482 nc v+ sense ssm2143 top view (not to scale) nc = no connect v out rev. information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents 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 analog devices. a C6 db differential line receiver ssm2143 one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 617/329-4700 fax: features high common-mode rejection dc: 90 db typ 60 hz: 90 db typ 20 khz: 85 db typ ultralow thd: 0.0006% typ @ 1 khz fast slew rate: 10 v/m s typ wide bandwidth: 7 mhz typ (g = 1/2) two gain levels available: g = 1/2 or 2 low cost general description the ssm2143 is an integrated differential amplifier intended to receive balanced line inputs in audio applications requiring a high level of immunity from common-mode noise. the device provides a typical 90 db of common-mode rejection (cmr), which is achieved by laser trimming of resistances to better than 0.005%. additional features of the device include a slew rate of 10 v/ m s and wide bandwidth. total harmonic distortion (thd) is less than 0.004% over the full audio band, even while driving low impedance loads. the ssm2143 input stage is designed to handle input signals as large as +28 dbu at g = 1/2. although primarily intended for g = 1/2 applications, a gain of 2 can be realized by reversing the +in/Cin and sense/reference connections. when configured for a gain of 1/2, the ssm2143 and ssm2142 balanced line driver provide a fully integrated, unity gain solution to driving audio signals over long cable runs. for similar performance with g = 1, see ssm2141. a 781/461-3113
rev. C2C ssm2143Cspecifications parameter symbol conditions min typ max units audio performance total harmonic distortion plus noise thd+n v in = 10 v rms, r l = 10 k w , f = 1 khz 0.0006 % signal-to-noise ratio snr 0 dbu = 0.775 v rms, 20 khz bw, rti C107.3 dbu headroom hr clip point = 1% thd+n +28.0 dbu dynamic response slew rate sr r l = 2 kw , c l = 200 pf 6 10 v/ m s small signal bandwidth bw C3 db r l = 2 kw , c l = 200 pf g = 1/2 7 mhz g = 2 3.5 mhz input input offset voltage v ios v cm = 0 v, rti, g = 2 C1.2 0.05 +1.2 mv common-mode rejection cmr v cm = 10 v, rto f = dc 70 90 db f = 60 hz 90 db f = 20 khz 85 db f = 400 khz 60 db power supply rejection psr v s = 6 v to 18 v 90 110 db input voltage range ivr common mode 15 v differential 28 v output output voltage swing v o r l = 2 k w 13 14 v minimum resistive load drive 2k w maximum capacitive load drive 300 pf short circuit current limit i sc +45, C20 ma gain gain accuracy C0.1 0.03 0.1 % reference input input resistance 18 k w voltage range 10 v power supply supply voltage range v s 6 18 v supply current i sy v cm = 0 v, r l = 2.7 4.0 ma specifications subject to change without notice. (v s = 6 15 v, C40 8 c t a +85 8 c, g = 1/2, unless otherwise noted. typical specifications apply at t a = +25 8 c) absolute maximum ratings supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 v common-mode input voltage . . . . . . . . . . . . . . . . . . . . 22 v differential input voltage . . . . . . . . . . . . . . . . . . . . . . . 44 v output short circuit duration . . . . . . . . . . . . . . .continuous operating temperature range . . . . . . . . . . . . C40 c to +85 c storage temperature range . . . . . . . . . . . . C65 c to +150 c junction temperature (t j ) . . . . . . . . . . . . . . . . . . . . +150 c lead temperature (soldering, 60 sec) . . . . . . . . . . . . +300 c thermal resistance 8-pin plastic dip (p): q ja = 103, q jc = 43 . . . . . . . . . c/w 8-pin soic (s): q ja = 150, q jc = 43. . . . . . . . . . . . . . c/w a
ssm2143 rev. C3C 10 90 100 0% 50mv 1 m s figure 1. s mall-signal transient response (v in = 200 mv, g = 1/2, r l = 2 k w , v s = 15 v, t a = +25 c) figure 3. thd+n vs. frequency (v s = 15 v, v in = 10 v rms, with 80 khz filter) figure 5. dynamic intermodulation distortion, dim-100 (v s = 15 v, r l = 100 k w ) 10 90 100 0% 5v 5 m s figure 2. l arge signal tran sient response (v in = +24 dbu, g = 1/2, r l = 2 k w v s = 15 v, t a = +25 c) figure 4. headroom (v s = 15 v, r l = 10 k w , with 80 khz filter) load resistance ? w 100 10k 1k 100k 1.0 0.0001 0.1 0.001 0.01 thd+n ? % figure 6. thd+n vs. load (v s = 15 v, v in = 10 v rms, with 1 khz sine, 80 khz filter) a
ssm2143 rev. C4C closed-loop gain ?db v s = ?5v t a = +25? frequency ?hz 10m 1k 100 100k 10k 1m 40 0 ?0 30 10 20 ?0 ?0 figure 8. closed-loop gain vs. frequency, 100 hz to 10 mhz 1m 1k 100 100k 10k frequency ?hz t a = +25? v s = ?5v 120 0 60 20 40 100 80 common-mode rejection ?db figure 10. common-mode rejection vs. frequency 1m 1k 100 100k 10k frequency ?hz 0 t a = +25? v s = ?5v output impedance ? w 2 10 6 4 8 figure 12. closed-loop output impedance vs. frequency figure 7. closed-loop gain vs. frequency, 20 hz to 20 khz (gain of 1/2 normalized to 0 db) ?80 180 ?0 ?35 0 ?5 45 90 135 phase ?degrees frequency ?hz 1k 100 100k 10k 1m 10m t a = +25? r l = 2k w v s = ?5v figure 9. closed-loop phase vs. frequency 140 0 60 20 40 120 80 100 power supply rejection ?db frequency ?hz 10 100 1m 100k 1k 10k ?srr +psrr t a = +25? v s = ?5v figure 11. power supply rejection vs. frequency v s = 15v t a = +25 c a
ssm2143 rev. C5C *the photographs in figure 17 through figure 19 were taken at v s = 15 v and t a = +25 c, using an external amplifier with a gain of 1000. frequency ?hz 1k 100k 10k 1m 10m v s = ?5v t a = +25? r l = 2k w g = 1/2 6 0 3 1 2 5 4 output voltage swing ? v rms figure 13. output voltage swing vs. frequency t = +25 c a supply voltage 0 20 5 15 10 40 0 30 10 20 output voltage swing ?v p? figure 15. output voltage swing vs. supply voltage 10 90 100 0% 5mv 1s 0.5m v 0v ?.5 m v figure 17. low frequency voltage noise from 0.1 hz to 10 hz* load resistance ? w 10 1k 100 10k output voltage swing ?v rms 0v 7.5v 2.5v 12.5v 5.0v 10.0v v = 15v t = +25 c s a figure 14. output voltage swing vs. load resistance t a = +25? v s = ?5v frequency ?hz 1 100 10 1k 10k 120 0 60 20 40 100 80 voltage noise density ?nv/ hz figure 16. voltage noise density vs. frequency 10 90 100 0% 5mv 10ms 5 m v 0v ? m v figure 18. voltage noise from 0 khz to 1 khz* a
ssm2143 rev. C6C *the photographs in figure 17 through figure 19 were taken at v s = 15 v and t a = +25 c, using an external amplifier with a gain of 1000. slew rate ?v/ m s 4 16 10 6 8 14 12 temperature ? c 75 25 50 ?0 ?5 100 0 r = 2k w v = 15v l s figure 20. slew rate vs. temperature temperature ? c 75 25 50 ?0 ?5 100 0 input offset voltage ? m v 400 0 300 100 200 v = 15v s figure 22. input offset voltage vs. temperature supply voltage ?v 0 ?0 ? ?5 ?0 supply current? ma 4.0 1.0 2.5 1.5 2.0 3.5 3.0 t a = +25? figure 24. supply current vs. supply voltage 10 90 100 0% 5mv 1ms 5 m v 0v ? m v figure 19. voltage noise from 0 khz to 10 khz* temperature ? c 75 25 50 ?0 ?5 100 0 gain error ?% 0.10 0 0.06 0.02 0.04 0.08 v = 10v v = 15v r = 0w s s in figure 21. gain error vs. temperature temperature ? c 75 25 50 ?0 ?5 100 0 v = 15v s 5 0 3 1 2 4 supply current ?ma figure 23. supply current vs. temperature a
ssm2143 rev. C7C applications information the ssm2143 is designed as a balanced differential line re- ceiver. it uses a high speed, low noise audio amplifier with four precision thin-film resistors to maintain excel lent common-mode rejection and ultralow thd. figure 25 shows the basic differen- tial receiver application where the ssm2143 yields a gain of 1/2. the pl acement of the input and feedback resistors can be switched to achieve a gain of +2, as shown in figure 26. for either circuit configuration, the ssm2143 can also be used un- balanced by grounding one of the inputs. in applications requir- ing a gain of +1, use the ssm2141. 6 3 5 1 4 2 7 6k 6k 12k 12k ?n +in ?5v 0.1? +15v 0.1? a = 2 v ssm2143 v out 6 1 2 4 5 7 12k 12k 6k 6k ?n +in ?5v 0.1? v out +15v 0.1? a = v 1 2 ssm2143 3 + figure 25. standard config- uration for gain of 1/2 cmrr the internal thin-film resistors are precisely trimmed to achieve a cmrr of 90 db. any imbalances introduced by the external circuitry will cause a significant reduction in the overall cmrr performance. for example, a 5 w source imbalance will result in a cmrr of 71 db at dc. this is also true for any reactive source impedances that may affect the cmrr over the audio frequency range. these error sources need to be minimized to maintain the excellent cmrr. to quantify the required accuracy of the thin film resistor matching, the source of cmrr error can be analyzed. a resistor mismatch can be modelled as shown in figure 27. by assuming a tolerance on one of the 12 k w resistors of d r, the equation for the common-mode gain becomes: v out v in = 6 k 6 k + 12 k 6 k 12 k +d r + 1 ? ? ? ? 6 k 12 k +d r which reduces to: v out v in = 1/3 d r 12 k +d r this gain error leads to a common-mode rejection ratio of: cmrr = | a dm | | a cm | @ 18 k dr ein +in 6k 6k 12k + d r 12k v out cmrr = 18k d r figure 27. a small mismatch in resistance results in a large common-mode error setting d r to 5 w results in the cmrr of 71 db, as stated above. to achieve the ssm2143s cmrr of 90 db, the resistor mismatch can be at most 0.57 w . in other words, to build this circuit discretely, the resistors would have to be matched to better than 0.005%! the following table shows typical resistor accuracies and the resulting cmrr for a differential amplifier. % mismatch cmrr 5% 30 db 1% 44 db 0.1% 64 db 0.005% 90 db dc output level adjust the reference node of the ssm2143 is normally connected to ground. however, it can be used to null out any dc offsets in the system or to introduce a dc reference level other than ground. as shown in figure 28, the reference node needs to be reference op27 +10v ?0v 6 1 2 3 4 5 7 12k 12k 6k 6k ?n +in ?5v 0.1? v out +15v 0.1? ssm2143 figure 28. a low impedance buffer is required to adjust the reference voltage. buffered with an op amp to maintain very low impedance to achieve high cmrr. the same reasoning as above applies such that the 6 k w resistor has to be matched to better than 0.005% or 0.3 w . the op amp maintains very low output impedance over the entire audio frequency range, as long as its bandwidth is well above 20 khz. the reference input can be adjusted over a 10 v range. the gain from the reference to the output is unity so the resulting dc output adjustment range is also 10 v. input errors the main dc input offset error specified for the ssm2143 is the input offset voltage. the input bias current and input offset current are not specified as for a normal operational amplifier. because the ssm2143 has built-in resistors, any bias current related errors are converted into offset voltage errors. thus, the offset voltage specification is a combination of the amplifiers offset voltage plus its offset current times the input impedance. figure 26. reversing the resistors results in a gain of 2 figure 29. ssm2142/ssm2143 balanced line driver/ receiver system 2 6 5 4 3 8 7 ssm2142 v in ssm2143 +18v ?8v +18v 0.1? 0.1? ?8v v out 3 7 6 4 1 2 5 all cable measurements use belden cable (500'). 1 a
ssm2143 rev. C8C line driver/receiver system the ssm2143 and ssm2142 provide a fully integrated line driver/ receiver system. the ssm2142 is a high performance balanced line driver ic that converts an unbalanced input into a b alanced output signal. it can drive large capacitive loads on long cables making it ideal for transmitting balanced audio signals. when com- bined with an ssm2143 on the receiving end of the cable, the sys- tem maintains high common-mode rejection and ultralow thd. the ssm2142 is designed with a gain of +2 and the ssm2143 with a gain of 1/2, providing an overall system gain of unity. the following data demonstrates the typical performance of the two parts together, measured on an audio precision at the ssm2143s output. this configuration was tested with 500 feet figure 30. thd+n vs. frequency of ssm2142/ssm2143 system (v s = 18 v, v in = 5 v rms, with 80 khz filter) figure 31. ssm2142/ssm2143 system headroomC see text(v s = 18 v, r l = 10 k w , 500' cable) figure 32. ssm2142/ssm2143 system dim-100 dynamic intermodulation distortion (v s = 18 v, r l = 10 k w ) of cable between the ics as well as no cable. the combination of the two parts results in excellent thd+n and snr and a noise floor of typically C105 db over a 20 hz to 20 khz bandwidth. a comment on ssm2142/ssm2143 system headroom is neces- sary. figure 31 shows a maximum signal handling of approximately 22 dbu, but it must be kept in mind that this is measured be- tween the ssm2142s input and ssm2143s output, which has been attenuated by one half. normally, the system would be shown as actually used in a piece of equipment, whereby the ssm2143 is at the input and ssm2142 at the output. in this case, the system could handle differential signals in excess of +24 dbu at the input and output, which is consistent with headroom requirements of most professional audio equipment. figure 33. ssm2142/ssm2143 system frequency response (v s = 18 v, v in = 0 dbv, 500' cable) 10 90 100 0% 5v 10m s figure 34. ssm2142/ssm2143 system large signal pulse response (v s = 18 v, r l = 10 k w , no cable) printed in u.s.a. 500' cable no cable 500' cable no cable a
ssm2143 rev. a C9C outline dimensions compliant to jedec standards ms-001 controlling dimensions are in inches; millimeter dimensions (in parentheses) are rounded-off inch equivalents for reference only and are not appropriate for use in design. corner leads may be configured as whole or half leads. 070606-a 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) seating plane 0.015 (0.38) min 0.210 (5.33) max 0.150 (3.81) 0.130 (3.30) 0.115 (2.92) 0.070 (1.78) 0.060 (1.52) 0.045 (1.14) 8 1 4 5 0.280 (7.11) 0.250 (6.35) 0.240 (6.10) 0.100 (2.54) bsc 0.400 (10.16) 0.365 (9.27) 0.355 (9.02) 0.060 (1.52) max 0.430 (10.92) max 0.014 (0.36) 0.010 (0.25) 0.008 (0.20) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.195 (4.95) 0.130 (3.30) 0.115 (2.92) 0.015 (0.38) gauge plane 0.005 (0.13) min figure 35. 8-lead plastic dual in-line package [pdip] narrow body (n-8) dimensions shown in inches and (millimeters) controlling dimensions are in millimeters; inch dimensions (in parentheses) are rounded-off millimeter equivalents for reference only and are not appropriate for use in design. compliant to jedec standards ms-012-aa 012407-a 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 1.75 (0.0688) 1.35 (0.0532) seating plane 0.25 (0.0098) 0.10 (0.0040) 4 1 85 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) bsc 6.20 (0.2441) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122) coplanarity 0.10 figure 36. 8-lead standard small outline package [soic_n] narrow body (r-8) dimensions shown in millimeters and (inches)
ssm2143 C10C rev. a ordering guide model 1 temperature range package description package option ssm2143pz ?40c to +85c 8-lead pdip n-8 SSM2143SZ ?40c to +85c 8-lead soic_n r-8 SSM2143SZ-reel ?40c to +85c 8-lead soic_n r-8 1 z = rohs compliant part revision history 6/11rev. 0 to rev. a updated outline dimensions ......................................................... 9 changes to ordering guide .......................................................... 10 11/91revision 0: initial version ?1991C2011 analog devices, inc. all rights reserved. trademarks and registered trademarks are the prop erty of their respective owners. d10010-0-6/11(a)
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