utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 1 qw-r108-014,a low voltage versatile telephone transmission circuit with dialler interface description the utc TEA1110A is a bipolar integrated circuit that performs all speech and line interface functions required in fully electronic telephone sets. it performs electronic switching between speech and dialling. the ic operates at a line voltage down to 1.6 v dc (with reduced performance) to facilitate the use of telephone sets connected in parallel. features *low dc line voltage; operates down to 1.6 v (excluding voltage drop over external polarity guard) *voltage regulator with adjustable dc voltage *provides a supply for external circuits *symmetrical high impedance inputs (64k ? ) for dynamic, magnetic or piezo-electric microphones *asymmetrical high impedance input (32k ? ) for electric microphones *dtmf input with confidence tone *mute input for pulse or dtmf dialling *receiving amplifier for dynamic, magnetic or piezo-electric earpieces *agc line loss compensation for microphone and earpiece amplifiers. dip-14 sop-14 applications * line powered telephone sets, cordless telephones, fax machines, answering machines. pin configuration 1 2 3 4 5 6 78 9 10 11 12 13 14 ln slpe reg n.c. dtmf mute ir vcc gar qr vee mic+ mic- agc
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 2 qw-r108-014,a pin description symbol pin no. pad no. description ln 1 1 positive line terminal slpe 2 2 slope (dc resistance) adjustment reg 3 3 line voltage regulator decoupling n.c. 4 4 not connected dtmf 5 5 dual-tone multi-frequency input mute 6 6 mute input to select speech or dialing mode (active low) ir 7 7 receiving amplifier input agc 8 8 automatic gain control/line loss compensation mic- 9 9 inverting microphone amplifier input mic+ 10 10 non-inverting microphone amplifier input vee 11 11 negative line terminal qr 12 12 earpiece amplifier output gar 13 13 earpiece amplifier gain adjustment vcc 14 14 supply voltage for internal circuit bonding pad locations coordinates symbol pad no. x y ln 1 -791 -82 slpe 2 -767.5 -460 rge 3 -445 -460 n.c. 4 -157.5 -460 dtmf 5 467 -460 mute 6 780.5 -459 ir 7 774.5 -205.5 agc 8 774.5 241 mic- 9 629.5 461 mic+ 10 375 461 v ee 11 -121.5 461 qr 12 -536.5 461 gar 13 -791 471 vcc 14 -791 227.5 unit: m
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 3 qw-r108-014,a absolute maximum ratings parameter symbol ratings unit positive continuous line voltage v ee -0.4 ~ 12 v repetitive line voltage during switch-on or line interruption v ln v ee -0.4 ~ 13.2 v maximum voltage on all pins v n (max) v ee -0.4 ~v cc +0.4 v maximum line current (r slpe =20 ) i iine 140 ma total power dissipation (ta=75 ) dip-14 sop-14 ptot 588 384 mw storage temperature tstg -40~+125 ambient temperature ta -25~+75 maximum junction temperature tj 125 electric characteristics (i line =15ma, v ee =0v, r slpe =20 , agc pin connected to vee, z line =600 , f=1khz, ta=25 , unless otherwise specified) parameter symbol conditions min typ max unit supplies (pins vln, vcc, slpe and reg) stabilized voltage between ln and slpe v ref 3.1 3.35 3.6 v i line = 1 ma 1.6 v i line = 4 ma 2.3 v i line = 15 ma 3.35 3.65 3.95 v dc line voltage v ln i line = 140 ma 6.9 v dc line voltage with an external resistor rva v ln(exr) r va(slpe-reg) = 27k 4.4 v dc line voltage variation with temperature referred to 25 c ? v ln(t) 30 mv internal current consumption i cc v cc = 2.9 v 1.1 1.4 ma supply voltage for peripherals vcc ip=0ma 2.9 v equivalent supply voltage resistance rccint ip=0.5ma 550 620 microphone amplifier (pins mic+ and mic-) voltage gain from mic+/mic- to ln gvtx v mic = 4 mv (rms) 42.7 43.7 44.7 db gain variation with frequency referred to 1 khz ? g vtx(f) f = 300 to 3400 hz 0.2 db gain variation with temperature referred to 25 ? g vtx(t) ta = -25 to +75 c 0.3 db common mode rejection ratio cmrr 80 db iline = 15 ma; thd = 2% 1.4 1.7 v maximum sending signal(rms value) v ln(max) (rms) iline = 4 ma, thd = 10% 0.8 v noise output voltage at pin ln, pins mic+/mic- shorted through 200 v notx -78.5 dbmp receiving amplifier (pins ir, qr and gar) voltage gain from ir to qr gvrx vir = 4 mv (rms) 32 33 34 db
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 4 qw-r108-014,a parameter symbol conditions min typ max unit gain variation with frequency referred to khz ? gvrx(f) 0.2 db gain variation with temperature referred to25c ? gvrx(t) ta = -25 to +75 c 0.3 db gain voltage reduction range ? g vrxr external resistor connected between gar and qr 14 db i p = 0 ma sine wave drive, r l = 150 ? , thd = 2% 0.25 v maximum receiving signal (rms value) v o(rms) i p = 0 ma sine wave drive, r l = 450 ? , thd = 2% 0.35 noise output voltage at pin r (rms value) v norx(rms) ? -87 dbvp automatic gain control (pin agc) gain control range for microphone and receiving amplifiers with respect to iiine=15ma ? gvtrx i line = 85 ma 5.9 db highest line current for maximum gain istart 23 ma lowest line current for minimum gain istop 56 ma dtmf amplifier (pin dtmf) voltage gain from dtmf to ln gvdtmf v dtmf = 20 mv (rms), mute = low 24.1 25.3 26.5 db gain variation with frequency referred to 1khz ? g vdtmf(f) f = 300 to 3400 hz 0.2 db gain variation with temperature referred to25c ? g vdtmf(t) t a = -25 to +75 c 0.4 db voltage gain from dtmf to qr (confidence tone) gvct v dtmf = 20 mv (rms), r l = 150 ? -15 db mute function (pin mute) low level input voltage v il v ee - 0.4 v ee +0.3 v high level input voltage v ih v ee +1.5 v cc +0.4 v input current i mute 1.5 a gain reduction for microphone and receiving amplifiers ? g vtrxm mute = low 80 db
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 5 qw-r108-014,a application information circuit (typical application of the utc TEA1110A in sets with pulse dialling or flash facilities) - + ir ln qr gar mic+ mic- slpe reg agc v ee vcc dtmf mute signal from dial and control circuits rcc 619 c reg 4.7 f + r slpe 20 zbal rast3 390 rast2 3.92k c ir rast1 130k rprotect 10 a/b b/a telephone line vdr 95v 4 bas11 bzx79c10 bsn254 r limit 3.9 bc547 bzx79c10 r pd1 470k r pd2 470k rpd3 1m c vcc 100 f + supply for peripheral circuits bf473 bc558 rpd4 470k rpd5 470k bc547 r pd6 68k pd input c gars c gar 100pf 1nf utc TEA1110A functional description supply (pins ln, slpe, vcc and reg) the supply for the utc TEA1110A and its peripherals is obtained from the telephone line (see fig.1). the ic generates a stabilized reference voltage (vref) between pins ln and slpe. vref is temperature compensated and can be adjusted by means of an external resistor (r va ). vref equals 3.35 v and can be increased by connecting r va between pins reg and slpe (see fig.2), or decreased by connecting rva between pins reg and ln. the voltage at pin reg is used by the internal regulator to generate vref and is decoupled by c reg , which is connected to v ee . this capacitor, converted into an equivalent inductance (see section ?set impedance?), realizes the set impedance conversion from its dc value (r slpe ) to its ac value (r cc in the audio-frequency range). the voltage at pin slpe is proportional to the line current. the voltage at pin ln is: v ln =v ref +r slpe i slpe i slpe =i iine -icc-ip-i* where: iline = line current icc = current consumption of the ic i p = supply current for peripheral circuits i* = current consum ed between ln and vee. the preferred value for r slpe is 20 ? . changing r slpe will affect more than the dc characteristics; it also influences the microphone and dtmf gains, the gain control characteristics, the sidetone level and the maximum output swing on the line.
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 6 qw-r108-014,a rcc 619 r line l line r exch v exch + i slpe slpe r slpe 20 reg c reg 4.7 f + v ee 2 3 11 + vd i sh 1 from pre amp icc i* vcc 14 ln + -+ c vcc 100 f peripheral circuits ip fig. 1 supply configuration. utc TEA1110A 6.0 3.0 5.0 4.0 10 4 10 5 10 6 10 7 (1) influence of r va on vref. (2) vref without influence of r va fig.2 reference voltage adjustment by r va vref (v) (1) (2) r va ( ) the internal circuitry of the utc TEA1110A is supplied from pin v cc . this voltage supply is derived from the line voltage by means of a resistor (r cc ) and must be decoupled by a capacitor cv cc . it may also be used to supply peripheral circuits such as dialling or control circuits. the v cc voltage depends on the current consumed by the ic and the peripheral circuits as shown by the formula: vcc=vcc 0 -rccint (ip-irec) vcc 0 =v ln -rcc i cc (see also figs 3 and 4). r ccint is the internal equivalent resistance of the volt age supply, and irec is the current consumed by the output stage of the earpiece amplifier. the dc line current flowing into the set is determined by the exchange supply voltage (vexch), the feeding bridge resistance (rexch), the dc resistance of the telephone line (rline) and the reference voltage (vref). with line currents below 7.5 ma, the internal reference voltage (generating vref) is automatically adjusted to a lower value. this means that more sets can operate in parallel with dc line voltages (excluding the polarity guard) down to an absolute minimum voltage of 1.6 v. at currents below 7.5 ma, the circuit has limited sending and receiving levels. this is called the low voltage area.
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 7 qw-r108-014,a 2.5 2 0.5 0 01 2 3 4 1.5 1 ip (ma) (1) (2) fig.3 typical current ip available from vcc for peripheral circuits at i iine =15ma. vcc (v) (1) with r va resistor. (2) without r va resistorl vcc v ee rccint vcco irec peripheral circuit ip + fig.4 vcc supply voltage for peripherals set impedance in the audio frequency range, the dynamic impedance is mainly determined by the r cc resistor. the equivalent impedance of the circuit is illustrated in fig.5. rcc 619 vcc cvcc 100 f + + rp reg c reg r slpe l eq vref slpe ln v ee l eq =c reg r slpe rp rp=internal resistance rp=15.5k fig.5 equivalent impedance between ln and v ee 20 4.7 f microphone amplifier (pins mic+ and mic-) the utc TEA1110A has symmetrical microphone inputs. the input impedance between pins mic+ and mic- is 64 k ? ( 2 32 k ? ). automatic gain control is provided on this amplifier for line loss compensation. receiving amplifier (pins ir, gar and qr) the receiving amplifier has one input (ir) and one out put (qr). the input impedance between pin ir and pin v ee is 20 k ? . the voltage gain from pin ir to pin qr can be decreased by connecting an external resistor r gar between pins gar and qr; the adjustment range is 14 db. two external capacitors c gar (connected between gar and qr) and c gars (connected between gar and v ee ) ensure stability. the c gar capacitor provides a first-order low-pass filter. the cut-off frequency corresponds to the time constant c gar (r garint // r gar ). r garint is the internal resistor (connected between pins gar and qr) which sets the gain with a typical value of 125 kw. the condition c gars = 10 c gar must be fulfilled to ensure stability. the output voltage of the receiving amplifier is specified for continuous wave drive. the maximum output swing depends on the dc line voltage, the r cc resistor, the i cc current consumption of the circuit, the i p current consumption of the peripheral circuits and the load impedance.
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 8 qw-r108-014,a automatic gain control is provided on this amplifier for line loss compensation. automatic gain control (pin agc) the utc TEA1110A performs automatic line loss compensat ion. the automatic gain control varies the gain of the microphone amplifier and the gain of the receiving amplifier in accordance with the dc line current. the control range is 5.9 db (which corresponds approximately to a line length of 5 km for a 0.5 mm diameter twisted-pair copper cable with a dc resistance of 176 ? /km and an average attenuation of 1.2 db/km). the ic can be used with different configurations of feeding bridge (suppl y voltage and bridge resistance) by connecting an external resistor r agc between pins agc and v ee . this resistor enables the i start and i stop line currents to be increased (the ratio between istart and istop is not affected by the resistor). the agc function is disabled when pin agc is left open-circuit. mute function (pin mute) the mute function performs the switching between the s peech mode and the dialling m ode. when mute is low, the dtmf input is enabled and the microphone and receiving amplifiers inputs are disabled. when mute is high, the microphone and receiving amplifiers inputs are enabled while the dtmf input is disabled. a pull-up resistor is included at the input. dtmf amplifier (pin dtmf) when the dtmf amplifier is enabled, dialling tones may be sent on line. these tones can be heard in the earpiece at a low level (confidence tone). the utc TEA1110A has an asymmetrical dtmf input. the input impedance between dtmf and v ee is 20 k ? . the automatic gain control has no effect on the dtmf amplifier. sidetone suppression the utc TEA1110A anti- sidetone network comprising rcc//zline, rast1, rast2, rast3, r slpe and zbal (see fig.6 ) suppresses the transmitted signal in the earpiece. maximum compensation is obtained when the following conditions are fulfilled: r slpe rast1=rcc (rast2+rast3) (rast2 (rast3+r slpe )) k= (rast1 r slpe ) zbal= k ziine the scale factor k is chosen to meet the compatibility with a standard capacitor from the e6 or e12 range for zbal. in practice, zline varies considerably with the line type and the line length. therefore, the value of zbal should be for an average line length which gives satisfactory sidetone suppression with short and long lines. the suppression also depends on the accuracy of the match between zbaland the impedance of the average line. the anti-sidetone network for the utc TEA1110A (as shown in application information circuit) attenuates the receiving signal from the line by 32 db before it enters the receiving amplifier. the attenuation is almost constant over the whole audio frequency range. im r a st1 zbal ra st3 slpe rast2 ir rc c v ee zline r slpe ln zir fig.6 equivalent circuit of utc TEA1110A anti-sidetone bridge
utc TEA1110A linear integrated circuit utc unisonic technologies co., ltd. 9 qw-r108-014,a utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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