U4056B1 preliminary information telefunken semiconductors rev. a1, 06-may-96 1 (10) low-voltage electronic speech circuit with dialer interface description the electronic speech circuit, U4056B1, is a linear inte- grated circuit for use in telephones and other line fed terminal equipment. it replaces the common speech circuit with carbon microphone, hybrid transformer, sidetone equivalent and ear protection rectifiers. a low-cost electrodynamic transducer is used as an earphone. it contains all components necessary for ampli- fication of signals and adaption to the line. features the microphone hybrid transformer is replaced by an electronic circuit asymmetrical input for electret microphone high performance through the use of dynamic transducers as the earphone (non-linear distortion ) optional automatic equalization of sending and receiving reference equivalent up to 5 km subscriber line length dtmf interface with muting supply voltage for dialer high range of line feeding current input resistance independent of line current and sidetone suppression circuit built-in ear protection by earphone voltage limiter high life expectancy due to reduced power consumption on the chip benefits operation possible from 5 ma U4056B1 : high level mute figure 1. block diagram and pin connection
U4056B1 telefunken semiconductors rev. a1, 06-may-96 preliminary information 2 (10) pin description pin symbol function 1, 2 h1 and h2 the push-pull complementary outputs of the receive amplifier: dynamic transducers with a minimum impedance of 100 can be directly driven by these outputs. 3 gnd ground 4 sidetone st the output of the sidetone can- cellation signal, requires a balanced impedance of eight to ten times the subscriber's line impedance to be connected to pin 13. 5 ck2 input to the line output driver amplifier. transmit a.g.c. is applied to this stage. 6 ck1 the transmit pre-amp output respective of the dtmf output which is normally capacitively coupled to pin 5. 7 mic in this input is intended to be capacitively coupled to a fet- buffered electret microphone 8 dtmf in the dtmf input has an internal resistor connected to ground. it provides the load resistor for the emitter of a cmos dtmf generator. this input is only active when mute (pin 9) is pulled high. 9 mute the mute input must be pulled at least to 1.5 v (mute) to mute the mic amp. and audio amp. and enable dtmf in. 10 v+ regulated output voltage of 2.7 v for biasing a dtmf generator activated by mute pin symbol function 11 v m regulated output voltage of 1.2 v suitable for low-voltage electret microphone 12 rec in the receive amplifier input. the receiving amplification is regu- lated by an a.g.c. 13 v l positive supply voltage input to the device. this input should be connected to the positive output of the polarity guard. the current through this pin is modulated by the transmit signal. 14 r dc an external resistor (2 w) is required from this pin to gnd to control the dc input impedance of the circuit. it has a nominal value of 56 for low-voltage operation. values up to 100 may be used to increase the available transmit output voltage swing at the expense of low- voltage operation. 15 v i this internal voltage bias line must be connected to v l via an external resistor r b , which dominates the ac input impedance of the circuit and should be 620 for an 600 input impedance or 910 for a 900 input impedance. 16 r agc the range of transmit and receive gain variations between short and long loops may be adjusted by connecting a resistor, r ex1 , from this pin to pin 3 (gnd). this pin can be left open to set a.g.c. out of action.
U4056B1 preliminary information telefunken semiconductors rev. a1, 06-may-96 3 (10) pin description in figure 2. absolute maximum ratings reference point pin 3, unless otherwise specified parameters symbol value unit line current i l 200 ma dc line voltage, t p = 3 ms, pin 13 v l 20 v power dissipation, i l = 100 ma p tot 560 mw junction temperature t j 150 c ambient temperature range t amb 28 to + 80 c storage temperature range t stg 55 to +150 c thermal resistance parameters symbol value unit junction ambient r thja 85 k/w
U4056B1 telefunken semiconductors rev. a1, 06-may-96 preliminary information 4 (10) electrical characteristics reference point pin 3, cable equivalent = l = 1 km, ? 0.5 mm, r' = 184 w , c' = 37 nf, f = 1300 hz, 0 db m = 775 mv rms, r ex2 = 56 w / 2 w, t exch = 48 v, r ex2 = 500 w , t amb = 25 c, unless otherwise specified. parameters test conditions / pins symbol min. typ. max. unit line voltage i l = 5 ma i l = 20 ma i l = 30 ma i l = 73 ma see figure 3 v l 1.3 2.7 3.6 7.5 1.7 3.0 4.0 8.5 2.1 3.3 4.5 9.5 v transmit and sidestone see figure 4 and 6 input resistance pin 7 3 23 28 33 k w gain i l = 30 ma 30 i l 73 ma g s g s 32 6 34 36 db noise at line weighted psophometrically i l = 73 ma n o 72 dbmp sidetone reduction 0 l 5 km g str 10 15 20 db dtmf amplifier input resistance pin 8 - 3 r d 8 10 13 k w dtmf gain i l = 30 ma 31 ma i l 73 ma g d g d 8 10 6 12 9 db db volume range d 5% i l = 30 ma v 0 0.9 1 v rms receiving amplifier see figure 5 input resistance pin 12 - 3 r i 40 50 60 k w receiving amplifier gain r hh = 300 w, i l = 30 ma r hh = 300 w 30 i l 73 ma g r g r 1 3 6 5 db receiving noise at earphone weighted psophometrically i l =73 ma, r hh = 300 w n i 80 dbmp gain change when muted i l 30 ma, r hh = 300 w g rm 15 20 26 db output saturation threshold i l 20 ma, r hh = 300 w v 0 1 1.5 v pp mute input mute-input current pin 9 = 1.5 v i m 10 20 30 m a mute off input voltage v m off 0.3 v mute on input voltage v m on 1.5 v supply voltage see figure 3 output voltage i l 20 ma mute switched off switched on pin 10 v+ 3 2.5 2.9 6.1 3.1 v output current i l 20 ma mute switched off switched on v+ = 2.5 v pin 10 i+ 1.0 30 1.2 ma output voltage i l 20 ma pin 11 v m 1.1 1.2 1.4 v output current i l 20 ma pin 11 i m 300 400 600 m a
U4056B1 preliminary information telefunken semiconductors rev. a1, 06-may-96 5 (10) figure 3. line and supply voltage characteristics
U4056B1 telefunken semiconductors rev. a1, 06-may-96 preliminary information 6 (10) ( ) g = 20 lg s g : sending gain at 0 km s v : line voltage in mute condition v l lm v lm ( ) str = 20 lg v l v str ( ) g = 20 lg sm v l v lm figure 4. transmitting amplification and sidetone reduction
U4056B1 preliminary information telefunken semiconductors rev. a1, 06-may-96 7 (10) ( ) g = 20 lg r v r v l ( ) g = 20 lg rm v r v rm g : sending gain at 0 km r v : receiving voltage when muted rm figure 5. receiving amplifier
U4056B1 telefunken semiconductors rev. a1, 06-may-96 preliminary information 8 (10) ( ) g = 20 lg d v l v dtmf g : dtmf gain at 0 km d figure 6. dtmf amplifier
U4056B1 preliminary information telefunken semiconductors rev. a1, 06-may-96 9 (10) ordering information extended type number package remarks U4056B1 dip16 dimensions in mm package: dip16
U4056B1 telefunken semiconductors rev. a1, 06-may-96 preliminary information 10 (10) ozone depleting substances policy statement it is the policy of temic telefunken microelectronic gmbh to 1. meet all present and future national and international statutory requirements. 2. regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. it is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances ( odss). the montreal protocol ( 1987) and its london amendments ( 1990) intend to severely restrict the use of odss and forbid their use within the next ten years. various national and international initiatives are pressing for an earlier ban on these substances. temic telefunken microelectronic gmbh semiconductor division has been able to use its policy of continuous improvements to eliminate the use of odss listed in the following documents. 1. annex a, b and list of transitional substances of the montreal protocol and the london amendments respectively 2 . class i and ii ozone depleting substances in the clean air act amendments of 1990 by the environmental protection agency ( epa ) in the usa 3. council decision 88/540/eec and 91/690/eec annex a, b and c ( transitional substances ) respectively. temic can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. we reserve the right to make changes to improve technical design and may do so without further notice . parameters can vary in different applications. all operating parameters must be validated for each customer application by the customer. should the buyer use temic products for any unintended or unauthorized application, the buyer shall indemnify temic against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. temic telefunken microelectronic gmbh, p.o.b. 3535, d-74025 heilbronn, germany telephone: 49 ( 0 ) 7131 67 2831, fax number: 49 ( 0 ) 7131 67 2423
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