SAA1094 ETC

Document overview

  • Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 1

Technical content

INTEGRATED CIRCUITS FOR TELEPHONE APPLICATIONS a SAA1094-2 Tone Ringer IC (14-Pin Plastic Package TO-116) This integrated CMOS circuit replaces the customary electromechani- — —_—_ ——- —_ — SAA 1094-2 - cal telephone ringer and calls the subscriber by a melodic tone se- Ti | quence, using a small magnetic or piezoceramic sound transducer. cama | Divider 5:1 TZ The tone ringer circuit, together with its transducer is powered by the Osctilator site| ringing current from the exchange. This makes it compatible with the { 13 conventional telephone network and, furthermore, no battery or mains oY 1; connections are needed. P| ; — > 3 ging _ Ringing ; | Generator Generator > 12 Functional Description i | . The tone ringer circuit normally derives the power required for its ope- Differentiator |_| ration from the ringing AC supplied by the exchange via lines a and b. | oe ng Switch | Together with the loop resistance, the 1 1 F isolating capacitor and a . 2.2 kQ resistor, the ringing generator in the exchange operates as an | Pulse Shaper | , alternating-current source. The 2.2 kQ resistor is needed to ensure a Frequency [| ° minimum impedance. The supplied alternating current is fed to pins 5 | Se Detection and 7 of the SAA1094-2 and is rectified by means of an integrated TT bridge circuit in the SAA1094-2. The rectified current charges the | Cas b electrolytic capacitor at pins 4 and 6. The direct voltage produced * = >e| Voltage | across this capacitor mainly depends on the loop resistance and on Monitoring the ringing frequency and is limited to the operating voltage Vz of the | | Zener diode integrated in the SAA1094-2. Tone ringing is switched on LT TT) EO T when the DC voltage across C, has reached the value of about 6 V. The ° switch-off threshold at decreasing supply voltage is about 3 V. SAA1094-2 Biock Diagram a TEA1045 Telephone Subset Amplifier (18-Pin Plastic Package) Features Re Au TEA 1045 Te f Fea fe a — Automatic compensation of line losses by using a gain-controlled (3s, send Sew Gan-Cortroted | Suput “Kar ! @) amplifier San | Preamplifier Mae Send Ampttier | Amplifier | S unitary — Very accurate (+2 dB) send, receive and VF (voice frequency) gains Dee f | > > > > =, feptenal] to achieve optimum system performance et sicetone Rod | — Low supply current obtained entirely from a small proportion of the Cecunt l line current 2! \\/S Rilene IH oof | — Cancellation circuit to achieve required reduction in sidetone Response | eT | — Balanced microphone input circuit for reduced sidetone yt! << < | Ea — Operation can be achieved if the subsets are paralleled HF sponse | te — Stabilised D.C. output for powering external VF oscillator pot Receive < < l, — Send, VF and receive gains can be preset externally by choice of wee | ee oc os | : resistors 7 Reference | os — Both low and high frequency characteristics (usually roll off’s) of the Lj nee Y send gain can be separately adjusted by external capacitors rn | « | 13 carmece Transducer be : — Control of quiescent operating point on curve relating D.C. line Set hecave Gain Tam +3.75¥ | selephone Line i - current with amplifier gain -" — Low send and receive noise TEA1045 Block Diagram and Application Circuit — Mute facility for send and receive amplifiers during dialling a

Description

The TEA1045 is a bipolar integrated circuit specially designed for use The overall characteristics of the TEA1045 are very well defined and in a telephone subset to amplify the output from the handset micro- controlled. Both send and receive gains within the integrated circuit phone to the telephone line and to amplify the incoming speech on have only a small overall spread of 4 dB (26% about nominal). With the line to the earpiece transducer. The microphone and earpiece line impedance and set-gain resistors closely controlled the per- transducers can be of the same type and construction. formance of the subset is well defined in the system. a ZSYO,7 Silicon Click Suppressor (DO-35 Package) Monolithic integrated analog circuit with symmetric V/l-characteristic for use as voltage limiter, e.g. as click suppressor in telephone subsets. es Type Maximum Ratings Characteristics at T, = 25°C Operating Surge Power Junction Forward Dynamic Residual Attenuation Current Current Dissipation Temperature Voltage Drop Resistance at Re = Ry = 600 Q, f = 0.2...4 kHz at at at at at Voltage Level at the Generator Ta = 25°C t= 100 us Ta =25°C lip] = 100 mA Jie] = 2 ma, -4N -0,5N ON - = 1kHz ~ ; + Ip MA + lesum A Prot MW °C |Ve| V rp G2 DWN DN DN