AS2520B AMSCO [austriamicrosystems AG], AS2520B Datasheet
AS2520B
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AS2520B Summary of contents
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Preliminary Austria Mikro Systeme International AG Key Features Line/speech circuit, loudhearing, handsfree and dc/dc converter on one 28 pin CMOS chip Operating range from 13 to 100 mA (down with reduced performance) Soft clipping control eliminating harsh ...
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Preliminary Pin Description Pin # Name Type Supply Supply GND 6 STB AI 7 LLC DI 8 LSI RTH AI ...
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Preliminary VOL D/ Supply AI DI: Digital Input DO: Digital Output DI/O: Digital Input/Output Operating ...
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Preliminary Functional Description The AS252x contains all the voice circuits needed in a high feature telephone instrument, i .e.: line adaptation (ac impedance, dc characteristics, 2/4-wire conversion, power extraction) handset speech circuit loudhearing with enhanced anti-Larsen handsfree with dynamic loop ...
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Preliminary DC Conditions The normal operating range (off-hook) is from 100 mA. Operating range performance is from (parallel operation). In the normal operating range all functions are operational. In the line hold ...
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... The anti-Larsen circuit decreases the gain of the loudspeaker amplifier when a microphone signal is applied signal is applied from the microphone, the loudspeaker amplifier is at its full gain. Anti-Clipping (not AS2520B/21B) The anti-clipping circuit is activated in loudhearing and handsfree mode. The circuit prevents harsh distortion at very high signal levels. ...
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Preliminary This approach has some disadvantages. It requires a high degree of discipline, since the three state channel control gives a very distinct half duplex with a relative high switching time constant to avoid chopper effects. Furthermore, the system is ...
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Preliminary The speech compression allows a higher gain in the transmit channel, i.e. the microphone gets more sensitive at low sound pressure levels on the microphone, which enables the user to move further away from the telephone. This means that ...
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Preliminary Electrical Characteristics Absolute Maximum Ratings* Supply Voltage............................................................................................................................... -0.3 Input Current..........................................................................................................................................+/- 25 mA Input Voltage (LS) ....................................................................................................................... -0.3V Input Voltage (LI, CS, SS).............................................................................................................-0.3V Input Voltage (STB, RI).........................................................................................................-2V Digital Input Voltage .......................................................................................................... -0.3V Electrostatic Discharge ..........................................................................................................................+/- 1000V Storage Temperature Range........................................................................................................... -65 ...
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Preliminary AC Electrical Characteristics mA 800 Hz; recommended operating conditions unless otherwise specified. LINE Transmit Symbol Parameter A Gain (M1/M2 to LS) TX Gain (M3/M4 to LS) A Gain ( Variation ...
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... LPD Rev. 5.1 Condition Volume reset f = 500 Hz to 3.4 kHz Speech mode; LLC = steps, each < 0 RMS Not AS2520B/21B Unloaded Channel control; V > 0 RMS Channel control HS = high 25°C AMB 50 Hz.........20 kHz V < 0 25°C ...
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Preliminary Test Circuit Rev. 5.1 AS252x Figure 8: Test Circuit Page 12 AS2520/21/20B/21B May 1999 ...
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Preliminary Application Diagramme La Lb INPUT FOR DTMF TONE RINGER MELODIES CONTROL INPUTS (FROM µC) 1µ5 1µ5 510 510 33 n MPSA92 2.2 mH 5V1 Applications Hints Interface to Microcontroller In off-hook condition the microcontroller can be supplied from V ...
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... Austria Mikro Systeme Int. AG reserves the right to change or discontinue this product without notice. Rev. 5.1 Ordering Information Part Package Number Type AS2520 T 28 pin SOP AS2520 P 28 pin DIP AS2520B T 28 pin SOP AS2520B 28 pin DIP P AS2521 T 28 pin SOP AS2521 P 28 pin DIP AS2521B T ...