1/10 n low noise : 3nv/ hz, 1.2pa/ hz n high output current : 200ma n very low harmonic and intermodu- lation distortion n high slew rate : 40v/ m s n specified for 25 w load description the ts612 is a dual operational amplifier featur- ing a high output current (200ma min.), large gain-bandwidth product (130mhz) and capable of driving a 25 w load with a 160ma output current at 6v power supply. this device is particularly intended for applications where multiple carriers must be amplified simulta- neously with very low intermodulation products. the ts612 is housed in so20 batwing plastic package for a very low thermal resistance. it is also available in tssop14 plastic package. this tiny package comes very interesting for surface saving. the ts612 is fitted out with power down function in order to decrease the consumption. application n upstream line driver for asymmetric digital subscriber line (adsl) (nt). order code d= small outline package (so) - also available in tape & reel (dt) p =thin skrink small outline package - only available in tape & reel (pt) pin connections (top view) part number temperature range package dp ts612id -40, +85 c ? ts612ipt -40, +85 c ? d so20 batwing (plastic micropackage) pt tssop14 (plastic micropackage) vcc+ 1 invertinginput 1 non-invertinginput1 vcc+ 2 vcc- vcc - power down 2 non-invertinginput 2 invertinginput2 gnd vcc - vcc- vcc - vcc - vcc- vcc - power down 1 vcc- output1 output 2 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 _ + _ + so20batwing - top view thermal heat tabs connectedto -vcc thermal heat tabs connectedto -vcc tssop14 - top v iew non-inverting input 2 power down 2 non-invertinginput 1 inverting input 1 vcc+1 output 1 vcc+2 nc vcc- 1 2 3 4 5 6 14 13 12 11 10 inverting input 2 o utput 2 nc power down 1 9 8 7 _ + gnd _ + ts612 dual wide band operational amplifier with high output current may 2001
ts612 2/10 absolute maximum ratings operating conditions electrical characteristics v cc = 6volts, t amb =25 c (unless otherwise specified) symbol parameter value unit v cc supply voltage 1) 7v v id differential input voltage 2) 2v v in input voltage range 3) 6v t oper operating free air temperature range ts612id, ts612ipt -40 to + 85 c t std storage temperature -65 to +150 c t j maximum junction temperature 150 c output short circuit duration 4) so20-batwing r thjc thermal resistance junction to case 25 c/w r thja thermal resistance junction to ambient area 45 c/w p max. maximum power dissipation (@25 c) 2.7 w tssop14 r thjc thermal resistance junction to case 32 c/w r thja thermal resistance junction to ambient area 110 c/w p max. maximum power dissipation (@25 c) 1.1 w 1. all voltages values, except differential voltage are with respect to network terminal. 2. differential voltages are non-inverting input terminal with respect to the inverting input terminal. 3. the magnitude of input and output voltages must never exceed v cc +0.3v. 4. an output current limitation protects the circuit from transient currents. short-circuits can cause excessive heating. destructive dissipation can result from short circuit on amplifiers. symbol parameter value unit v cc supply voltage 2.5 to 6v v icm common mode input voltage (v cc - )+2to(v cc + )-1 v symbol parameter test conditi on min. typ. max unit dc performance v io input offset voltage t amb -6 -1 6 mv t min. ts612 3/10 dynamic performance and output characteristics v oh high level output voltage i out = 160ma r l connected to gnd 4 4.5 v v ol low level output voltage i out = 160ma r l connected to gnd -4.5 -4 v a vd large signal voltage gain v out = 7v peak r l =25 w ,t amb 6500 11000 v/v t min. ts612 4/10 power down mode v cc = 6volts, t amb =25 c power down equivalent shematic ouput impedance in power down mode in power down mode the output of the driver is in ohigh impedanceo state. it is really the case for the static mode. regarding the dynamic mode, the im- pedance decreases due to a capacitive effect of the collector-substrat and base collector junction. the impedance behaviour comes capacitive, typi- cally: 1.4m w // 33pf. intermodulation distortion the curves shown below are the measurements results of a single operator wired as an adder with a gain of 15db. the operational amplifier is supplied by a symmet- ric 6v and is loaded with 25 w . two synthesizers (rhode & schwartz sme) gen- erate two frequencies (tones) (70 & 80khz or 180 & 280khz). an hp3585 spectrum analyzer measures the spu- rious level at different frequencies. the curves are traced for different output levels (the value in the x ax is the value of each tone). the output levels of the two tones are the same. the generators and spectrum analyzer are phase locked to enhance measurement precision. 3rd order intermodulation (2 tones : 70khz and 80khz) 2nd order intermodulation spurious measurement @ 100khz (2 tones : 180khz and 280khz) 3rd order intermodulation (2 tones : 180khz and 280khz) symbol parameter min. typ. max unit v pdw thershold voltage for power down mode v low level 0 0.8 high level 2 3.3 icc pdw power down mode current consumption 75 m a r pdw power down mode ouput impedance 1.4 mw c pdw power down mode output capacitance 33 pf standby control operator status pin (1) operator 1 pin (7) operator 2 operator 1 operator 2 v high level v low level standby active v high level v high level standby standby v low level v low level active active v low level v high level active standby + _ . . .. v cc - v cc + power down ouput . 1 1,5 2 2,5 3 3,5 4 4,5 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 im3 (dbc) vout peak (v) 230khz 220khz 90khz 60khz vout peak (v) 1,5 2 2,5 3 3,5 4 4,5 -70 -65 -60 -55 im2 (dbc) 1 1,5 2 2,5 3 3,5 4 4,5 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 im3 (dbc) vout peak (v) 80khz 640khz 380khz 740khz
ts612 5/10 closed loop gain and phase vs. frequency gain=+2, vcc= 6v, rl=25 w closed loop gain and phase vs. frequency gain=+11, vcc= 6v, rl=25 w maximum output swing vcc= 6v, rl=25 w closed loop gain and phase vs. frequency gain=+6, vcc= 6v, rl=25 w equivalent input voltage noise gain=+100, vcc= 6v, no load channel separation (xtalk) vs. frequency xtalk=20log(v2/v1), vcc= 6v, rl=25 w -30 -20 -10 0 10 gain (db) -200 -100 0 100 200 phase (degrees) 10khz 100khz 1mhz 10mhz 100mhz frequency gain phase -30 -20 -10 0 10 20 30 gain (db) -200 -100 0 100 200 phase (degrees) 10khz 100khz 1mhz 10mhz 100mhz frequency gain phase 0 246810 time ( m s) -5 -4 -3 -2 -1 0 1 2 3 4 5 swing (v) output input -20 -15 -10 -5 0 5 10 15 20 gain (db) -200 -100 0 100 200 phase (degrees) 10khz 100khz 1mhz 10mhz 100mhz frequency gain phase 100hz 1khz 10khz 100khz 1mhz 0 5 10 15 20 en (nv/vhz) _ + 100 10k frequency -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 xtalk (db) 10khz 100khz 1mhz 10mhz frequency 100w + _ 1 k w 49.9w v1 vin 100w + _ 1 k w 49.9w v2 25w 25w
6/10 adsl concept asymmetric digital subscriber line (adsl), is a new modem technology, which converts the exist- ing twisted-pair telephone lines into access paths for multimedia and high speed data communica- tions. adsl transmits more than 8 mbps to a subscriber, and can reach 1mbps from the subscriber to the central office. adsl can literally transform the ac- tual public information network by bringing mov- ies, television, video catalogs, remote cd-roms, lans, and the internet into homes. an adsl modem is connected to a twisted-pair telephone line, creating three information chan- nels: a high speed downstream channel (up to 1.1mhz) depending on the implementation of the adsl architecture, a medium speed upstream channel (up to 130khz) and a pots (plain old telephone service), split off from the modem by filters. the line interface - adsl remote terminal (rt): the figure1 shows a typical analog line interface used for adsl. the upstream and downstream signals are separated from the telephone line by using an hybrid circuit and a line transformer. on this note, the accent will be made on the emission path. the ts612 is used as a dual line driver for the up- stream signal. for the remote terminal it is required to create an adsl modem easy to plug in a pc. in such an ap- plication, the driver should be implemented with a +12 volts single power supply. this +12v supply is available on pci connector of purchase. the figure 2 shows a single +12v supply circuit that uses the ts612 as a remote terminal trans- mitter in differential mode. the driver is biased with a mid supply (nominaly +6v), in order to maintain the dc component of the signal at +6v. this allows the maximum dy- namic range between 0 and +12 v. several op- tions are possible to provide this bias supply (such as a virtual ground using an operational amplifier), such as a two-resistance divider which is the cheapest solution. a high resistance value is re- quired to limit the current consumption. on the other hand, the current must be high enough to bias the inverting input of the ts612. if we consid- er this bias current (5 m a) as the 1% of the current through the resistance divider (500 m a) to keep a stable mid supply, two 47k w resistances can be used. the input provides two high pass filters with a break frequency of about 1.6khz which is neces- sary to remove the dc component of the input sig- nal. to avoid dc current flowing in the primary of the transformer, an output capacitor is used. figure 1 : typical adsl line interface impedance matching twisted-pair telephone line hybrid circuit digital treatment lp filter ts612id line driver reception (analog) emission (analog) digital to analog analog to digital high output current reception circuits upstream downstream figure 2 : ts612 as a differential line driver with a +12v single supply r1 r3 r2 vi vi vo vo gnd +12v 25 w 100w 1:2 hybrid & transformer gnd +12v 47k 47k 10 m 10 0n 100n 100n 1k 1k 12.5 12.5 10n 1 m +12v + _ + _ gnd typical application : ts612 as driver for adsl line interfaces a single supply implementation with passive or active impedance matching by c. prugne
ts612 7/10 the 1 m f capacitance provides a path for low fre- quencies, the 10nf capacitance provides a path for high end of the spectrum. in differential mode the ts612 is able to deliver a typical amplitude signal of 18v peak to peak. the dynamic line impedance is 100 w . the typical value of the amplitude signal required on the line is up to 12.4v peak to peak. by using a 1:2 trans- former ratio the reflected impedance back to the primary will be a quarter (25 w ) and therefore the amplitude of the signal required with this imped- ance will be the half (6.2 v peak to peak). assum- ing the 25 w series resistance (12.5 w for both out- puts) necessary for impedance matching, the out- put signal amplitude required is 12.4 v peak to peak. this value is acceptable for the ts612. in this case the load impedance is 25 w for each driv- er. for the adsl upstream path, a lowpass filter is absolutely necessary to cutoff the higher frequen- cies from the dac analog output. in this simple non-inverting amplification configuration, it will be easy to implement a sallen-key lowpass filter by using the ts612. for adsl over pots, a maxi- mum frequency of 135khz is reached. for adsl over isdn, the maximum frequency will be 276khz. increasing the line level by using an active impedance matching with passive matching, the output signal ampli- tude of the driver must be twice the amplitude on the load. to go beyond this limitation an active maching impedance can be used. with this tech- nique it is possible to keep good impedance matching with an amplitude on the load higher than the half of the ouput driver amplitude. this concept is shown in figure3 for a differential line. component calculation: let us consider the equivalent circuit for a single ended configuration, figure4. let us consider the unloaded system. assuming the currents through r1, r2 and r3 as respectively: as vo equals vo without load, the gain in this case becomes : the gain, for the loaded system will be (1): as shown in figure5, this system is an ideal gener- ator with a synthesized impedance as the internal impedance of the system. from this, the output voltage becomes: with ro the synthesized impedance and iout the output current. on the other hand vo can be ex- pressed as: by identification of both equations (2) and (3), the synthesized impedance is, with rs1=rs2=rs: figure 3 : ts612 as a differential line driver with an active impedance matching r1 r4 r2 vi vi vo vo 25 w 100w 1:2 hybrid & transformer gnd +12v 47k 47k 10 m 100n 100n 100n 1k 1k 12.5 12.5 10n 1 m r3 r5 vo vo gnd +12v +12v + _ + _ gnd figure 4 : single ended equivalent circuit 1/2 r1 r2 r3 + _ vi vo rs1 -1 vo 1/2 rl 2 vi r 1 -------- - vi vo () r 2 -------------------------- and vi vo + () r 3 ----------------------- - , g vo noload () vi ------------------------------- 1 2 r 2 r 1 ---------- - r 2 r 3 ------ - ++ 1 r 2 r 3 ------ - ---------------------------------- - == gl vo withload () vi ------------------------------------ 1 2 -- - 1 2 r 2 r 1 ---------- - r 2 r 3 ------ - ++ 1 r 2 r 3 ------ - ---------------------------------- - 1 () , == vo vig () roiout () = 2 () , vo vi 1 2 r 2 r 1 ---------- - r 2 r 3 ------- ++ ?? ?? 1 r 2 r 3 ------ - ---------------------------------------------- - rs 1 iout 1 r 2 r 3 ------ - --------------------- 3 () , = ro rs 1 r 2 r 3 ------ - ---------------- - 4 () , =
ts612 8/10 figure 5 : equivalent schematic. ro is the synthesized impedance unlike the level vo required for a passive imped- ance, vo will be smaller than 2vo in our case. let us write vo =kvo with k the matching factor vary- ing between 1 and 2. assuming that the current through r3 is negligeable, it comes the following resistance divider: after choosing the k factor, rs will equal to 1/2rl(k-1). a good impedance matching assumes: from (4) and (5) it becomes: by fixing an arbitrary value for r2, (6) gives: finally, the values of r2 and r3 allow us to extract r1 from (1), and it comes: with gl the required gain. capabilities the table below shows the calculated compo- nents for different values of k. in this case r2=1000 w and the gain=16db. the last column displays the maximum amplitude level on the line regarding the ts612 maximum output capabilities (18vpp diff.) and a 1:2 line transformer ratio. power consumption in communication conditions: passive impedance matching transformer turns ratio: 2 power supply: 12v maximun level required on the line: 12.4vpp maximum output level of the driver: 12.4vpp crest factor: 5.3 (vp/vrms) power supply: 12v the ts612 power consumption during emission on 900 and 4550 meter twisted pair telephone lines: 450mw gl (gain for the loaded system) gl is fixed for the application requirements gl=vo/vi=0.5(1+2r2/r1+r2/r3)/(1-r2/r3) r1 2r2/[2(1-r2/r3)gl-1-r2/r3] r2 (=r4) abritrary fixed r3 (=r5) r2/(1-rs/0.5rl) rs 0.5rl(k-1) ro vi.gi iout 1/2 rl ro kvorl rl 2 rs 1 + --------------------------- = ro 1 2 -- - rl 5 () , = r 2 r 3 ------- 1 2 rs rl --------- - 6 () , = r 3 r 2 1 2 rs rl --------- - ------------------- = r 1 2 r 2 21 r 2 r 3 ------- ?? ?? gl 1 r 2 r 3 ------ - --------------------------------------------------------- 7 () , = active matching k r1 ( w ) r3 ( w ) rs ( w ) ts612 output level to get 12.4vpp on the line (vpp diff) maximum line level (vpp diff) 1.3 820 1500 3.9 8 27.5 1.4 490 1600 5.1 8.7 25.7 1.5 360 2200 6.2 9.3 25.3 1.6 270 2400 7.5 9.9 23.7 1.7 240 3300 9.1 10.5 22.3 passive matching 12.4 18
ts612 9/10 package mechanical data 20 pins - plastic micropackage (so) dim. millimeters inches min. typ. max. min. typ. max. a 2.65 0.104 a1 0.1 0.3 0.004 0.012 a2 2.45 0.096 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.013 c 0.5 0.020 c1 45 (typ.) d 12.6 13.0 0.496 0.512 e 10 10.65 0.394 0.419 e 1.27 0.050 e3 11.43 0.450 f 7.4 7.6 0.291 0.299 l 0.5 1.27 0.020 0.050 m 0.75 0.030 s8 (max.)
ts612 10/10 package mechanical data 14 pins - thin shrink small outline package (tssop) dim. millimeters inches min. typ. max. min. typ. max. a 1.20 0.05 a1 0.05 0.15 0.01 0.006 a2 0.80 1.00 1.05 0.031 0.039 0.041 b 0.19 0.30 0.007 0.15 c 0.09 0.20 0.003 0.012 d 4.90 5.00 5.10 0.192 0.196 0.20 e 6.40 0.252 e1 4.30 4.40 4.50 0.169 0.173 0.177 e 0.65 0.025 k0 8 0 8 l 0.50 0.60 0.75 0.09 0.0236 0.030 c e1 k l e e b d pin 1 identification 1 7 8 14 seating plane c aaa c 0,25 mm .010 inch gage plane l1 a a2 a1 information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibil ity for the consequences of use of such information nor for any infring ement of patents or other righ ts of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specifications mentioned in this publication are subject to change witho ut notice. this publ ication supersedes and replaces all information previously supplied. stmicroelectronics products are not authorized for use as critical components in life suppo rt devices or systems withou t express written approval of stmicroelectronics. ? the st logo is a registered trademark of stmicroelectronics ? 2001 stmicroelectronics - printed in italy - all rights reserved stmicroelectronics group of companies australia - brazil - china - finland - france - germany - hong kong - india - italy - japan - malaysia - malta - morocco singapore - spain - sweden - switzerland - united kingdom ? http://www. st.com
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