AS2504 | DigiCamel IC Datasheet

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AS2504 AMSCO | Alldatasheet

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Manufacturer or author: htr
PDF pages: 12

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Austria Mikro Systeme International AG Cordless telephone, answering machine line interface Key Features Analogue line interface and speech circuit for a/b terminals on a 28-pin CMOS-IC 2 balanced transmit inputs 3 unbalanced transmit inputs 2 buffered single ended receive outputs (RL>150Ω) 1 auxiliary single ended receive output (RL>10kΩ) Low noise (max. -72dBmp) Soft clipping to avoid harsh distortion Operating range from 15mA to 100mA (down to 5mA with reduced performance) Line loss compensation selectable by pin option Real and complex impedance selectable by external components Side tone adaptation selectable by external components Digital controls input for mode selection Rx volume control General Description AS2504 is a CMOS integrated circuit that incorporates DC and AC line adaptation (DC- mask and synthesised AC-impedance of 1000Ω) as well as a speech circuit with softclipping, line loss compensation and Rx- volume control. It shall act as an a/b-line powered or auxiliarily powered device, which is controlled by a CPU. Application Cordless base stations, answering machines, a/b-line or auxiliary powered telephone sets. Package Available in 28 pin SOIC Block Diagram

Pin # Symbol Function LS Line Current Sense Input Input for sensing the line current LI Line Input Input used for power extraction and line current sensing RI Receive Input Input for ac-separated receive signal STB Side Tone Balance Input Input for side tone cancellation network CS Current Shunt Control Output N-channel open drain output to control the external high power shunt transistor for synthesising AC- and DC-impedance, modulation of line voltage and shorting the line during make periods of pulse dialling CI Complex Impedance Input Input pin for the capacitor to program a complex impedance MASK MASK Input pin to set circuit into power down mode during e.g. LD-dialling. During MASK=HIGH, CS-pin is internally shorted to ground. LLC Line Loss Compensation Select Pin 45mA-75mA —> VDD 20mA-50mA —> AGND None —> VSS VDD Voltage Drain Drain Positive Power Supply, for external circuitry t.m. 4.0mA@IL=20mA and 4.0mA@IL=20mA VSS Voltage Source Source Negative Power Supply AGND Analogue Ground Special ground for the internal amplifiers Microphone Input 1 Differential input for the microphone (electret) Microphone Input 2 Differential input for the microphone (electret) Microphone Input 3 Differential input for the microphone (electret) Microphone Input 4 Differential input for the microphone (electret) ATI1 Auxiliary Transmit Input 1 RI >= 25kΩ ATI2 Auxiliary Transmit Input 2 RI >= 100kΩ

Pin # Symbol Function ATI3 Auxiliary Transmit Input 3 RI >= 100kΩ ROH1 Receive Output to Handset 1 Output for driving a dynamic earpiece with an impedance from 150Ω to 300Ω (max. 0.7Vp) ROH2 Receive Output to Handset 2 Output for driving a dynamic earpiece with an impedance from 150Ω to 300Ω (max. 1.4Vp) ARO1 Auxiliary Receive Output 1 RL > 10kΩ (max. 1.4Vp) VOL VOLume Input pin for increasing (= connect to VIN >= VDD-0.3V) or decreasing (= connect to VIN <= VSS+0.3V) the Rx volume. The idle state is between VSS+1.4V < VIN < VDD-1.4V. Max rise time 50ns, max fall time 50ns, min pulse width 1us HSS HandSet or HeadSet / bit Digital input to select the ROH1 or ROH2 signal output path RX0 Receive 0 / bit Digital input to select a signal path AUX0 Auxiliary 0 / bit Digital input to select a signal path AUX1 Auxiliary 1 / bit Digital input to select a signal path TX0 Transmit 0 / bit Digital input to select a signal path TX1 Transmit 1 / bit Digital input to select a signal path

There are 3 possible modes: Idle Mode: AS2504 is disconnected from the a/b-line (= no line current) and VDD is not supplied by auxiliary power. All internal circuits are powered down. Input of digital control signals is not possible. Line Power Mode: AS2504 is connected to the a/b-line and VDD is generated by the internal power extraction. The speech circuit is powered up. The line interface circuit is functional (DC-mask and AC-impedance are synthesised). Input of digital control signals is possible. Aux. Power Mode: AS2504 is disconnected from the a/b-line (= no line current) and VDD is supplied by auxiliary power. The speech circuit is powered up. The line interface circuit is not functional (DC-mask and AC-impedance). Input of digital control signals is possible. Start-up in Line Power Mode As soon as AS2504 is supplied with line current, the external Vdd capacitor will be charged up via the LI- and VDD-pin. After the Vdd voltage has reached the operating level of 2V, the line interface circuit and the selected signal path of the speech circuit is switched on. This off-hook status is signalled to the internal logic via the LS-pin (voltage level sensitive). Start-up in Aux. Power Mode As soon as AS2504 is supplied with auxiliary power at the VDD-pin, the selected signal path of the speech circuit is switched on. The line interface circuit (DC-mask and AC-impedance) is not functional. This on-hook status is signalled to the internal logic via the LS-pin (voltage level sensitive). DC conditions The normal operating mode is from 15mA to 100mA. An operating mode with reduced performance is from 5mA to 15mA. In the line hold range from 0mA to 5mA the device is in a power down mode and the voltage at LI is reduced to a maximum of 3.5V The DC characteristic is determined by the voltage at LI-pin and a 30Ω resistor between LI- and LS-pin. It can be calculated by the following equation: VLS = VLI + ILine * 30Ω. The t.m. voltage at the LI-pin is 4.5V. The calculation leads to the following DC resistances: 330Ω to 75Ω at line currents from 15mA to 100mA. With a HIGH at the MASK-pin, the speech circuit and other parts of the device, which are not needed for operation, are in power down mode in order to save current. The CS-pin is pulled to Vss to turn the external shunt transistor fully on. This guarantees a low voltage drop (<1V) at the LI-pin during make periods of pulse dialling or flash. 2/4 wire conversion AS2504 has a built-in dual Wheatstone bridge with one common ground. This provides a maximum of independence of AC-impedance and side tone from each other. One can adapt side tone without changing the AC-impedance. AC-impedance The AC-impedance of AS2504 is set to t.m. 1000Ω. With the external capacitor at CI-pin it can be programmed complex. With an external resistor of approx. 1.5kΩ connected to the LS- pin it can be programmed to 600Ω. ZAC(syn) = 33 * 30Ω. Side Tone A good sidetone cancellation can be achieved by using the following equation: ZBAL/ZLINE = 10 Transmit path The gain of the M1/M2 —> LS is set to 37dB. The input is differential with an impedance of 20kΩ. The soft clip circuit limits the output voltage at LS to 2Vp. The attack time is 30µs/6dB and the decay time is 20ms/6dB. The gain of the M3/M4 —> LS is set to 43dB. The input is differential with an impedance of 10kΩ. The soft clip circuit limits the output voltage at LS to 2Vp. The attack time is 30µs/6dB and the decay time is 20ms/6dB.

The gain of the ATI1 —> LS is set to 6dB. The input is unbalanced with an impedance of 25kΩ. There is no softclipping. The gain of the ATI2 —> LS is set to 20dB. The input is unbalanced with an impedance of 100kΩ. There is no softclipping. Intercom path The gain of the ATI3 —> ROH1 is set to 6dB. The input is unbalanced with an impedance of 100kΩ. There is no softclipping. The gain of the ATI3 —> ROH2 is set to 12dB. The input is unbalanced with an impedance of 100kΩ. There is no softclipping. The gain of the M1/M2 —> ARO1 is set to 23dB. The input is differential with an impedance of 20kΩ. The soft clip circuit limits the output voltage at ARO1 to 0.4Vp. The attack time is 30µs/6dB and the decay time is 20ms/6dB. The gain of the M3/M4 —> ARO1 is set to 29dB. The input is differential with an impedance of 10kΩ. The soft clip circuit limits the output voltage at ARO1 to 0.4Vp. The attack time is 30µs/6dB and the decay time is 20ms/6dB. Receive path The gain of the LS —> ROH1 receive path is set to 3dB. The receive input is the differential signal of RI and STB. The soft clip circuit limits the output voltage at ROH1 to 0.7Vp. It prevents harsh distortion and acoustic shock. There is volume control and LLC for this path. The gain of the LS —> ROH2 receive path is set to 9dB. The receive input is the differential signal of RI and STB. The soft clip circuit limits the output voltage at ROH2 to 1.4Vp. It prevents harsh distortion and acoustic shock. There is volume control and LLC for this path. The gain of the LS —> ARO1 receive path is set to 3dB. The receive input is the differential signal of RI and STB. There is no softclipping, no LLC and no volume control for this path. Rx volume control The volume control is available for LS —> ROH1 and LS —> ROH2. It can be decreased by 6dB and increased by 8dB in 2dB steps from the default levels as described in the last paragraph. It remains in the pre-set position as long as VDD does not decrease less than 2.2V Line Loss Compensation The line loss compensation is a pin option. When it is activated, the transmit and receive gains for both I/O’s are decreased by 6dB at line currents from 20mA to 50mA when the LLC-pin is connected to AGND and from 45mA to 75mA when the LLC-pin is connected to VDD. The line loss compensation is deactivated when LLC-pin is connected to VSS. Digital interface The selection of the available signal paths must be set via the digital control pins. The following modes are possible: HSS: bit RX0: bit LS —> ROH1 LS —> ROH2 ATI3 —> ROH1 ATI3 —> ROH2 AUX0: bit AUX1: bit HSS: bit X MUTE M1/M2 —> ARO1 M3/M4 —> ARO1 X LS —> ARO1 X MUTE TX0: bit TX1: bit HSS: bit M1/M2 —> LS M3/M4 —> LS X ATI1 —> LS X ATI2 —> LS X MUTE

Electrical characteristics

Electrical charateristics are measured with the Test Circuit application. Typical mean values will not be tested. Absolute maximum ratings Positive Supply Voltage -0.3V <= VDD <= 7V Input Current ± 25mA Input Voltage (LS) -0.3V <= Vin <= 12V Input Voltage (LI, CS) -0.3V <= Vin <= 8V Input Voltage (STB, RI) -2V <= Vin <= VDD+0.3V Digital Input Voltage -0.3V <= Vin <= VDD+0.3V Electrostatic Discharge (HBM 1.5kΩ-100pF) ± 1000V Storage Temperature -65°C to +125°C Recommended operating conditions Supply Voltage (generated internally) 4V <= VDD <= 5V Operating Temperature -25°C to +70°C DC characteristics ILine=15mA w/o operation of any additional external circuitry, unless other specified Symbol Parameter Conditions Min Typ Max Units IDD Operating Current Speech Mode MASK=H, VDD=2.5V 300 mA µA VLI Line Voltage 15mA<=ILINE<=100mA 4.2 4.5 4.8 V IOL Output Current, Sink CS VOL=0.4V mA VIL Digital Input Voltage LOW Pins HSS,RX0,TX0, TX1,AUX0,AUX1 VSS

0.2 VDD

V VIH Digital Input Voltage HIGH Pins HSS,RX0,TX0, TX1,AUX0,AUX1

0.8 VDD

V

V ILine=15mA f=800Hz, unless other specified Symbol Parameter Conditions Min Typ Max Units AM1/2TX Transmit Gain M1/M2 —> LS ZAC(syn)=1000Ω +36.0 +37.5 +39.0 dB AM3/4TX Transmit Gain M3/M4 —> LS ZAC(syn)=1000Ω +42.0 +43.5 +45.0 dB AAT1X Transmit Gain ATI1 —> LS ZAC(syn)=1000Ω +5.0 +6.5 +8.0 dB AAT2X Transmit Gain ATI2 —> LS ZAC(syn)=1000Ω +19.0 +20.5 +22.0 dB ∆ATX Variation with frequency f = 500Hz … 3.4kHz ±0.8 dB THD Distortion VLS=0.25VRMS VUFC Unwanted Freq. Comp. f = 200Hz … 20kHz -60 dBm VAGC1 Soft Clip Level M1/M2 —> LS at LS 2.0 VP VAGC2 Soft Clip Level M3/M4 —> LS at LS 2.0 VP ASCO Soft Clip Overdrive M1/M2 - M3/M4 dB tattack tdecay Attack time Decay time µs/6dB ms/6d B ZIN-M1/2 Input Impedance M1/M2 kΩ ZIN-M3/4 Input Impedance M3/M4 kΩ ZIN-ATI1 Input Impedance ATI1 kΩ ZIN-ATI2 Input Impedance ATI2 100 kΩ AMUTE Mute Attenuation M1/2 - M3/4 dB VINmax Input Voltage Range M1/2 - M3/4 differential Vp VNO Noise Output Voltage LS TAMP=25°C -71 dBmp RL ∆ZAC/°C Return Loss Temp. Variation ZAC(syn)=1000Ω 0.5 dB Ω/°C

ILine=15mA f=800Hz, unless other specified Symbol Parameter Conditions Min Typ Max Units AM1/2IX Intercom Gain M1/M2 —> ARO1 +21.5 +23.0 +24.5 dB AM3/4IX Intercom Gain M3/M4 —> ARO1 +27.2 +28.7 +30.2 dB AAT3IX Intercom Gain ATI3 —> ROH1 +4.5 +6.0 +7.5 dB AAT4IX Intercom Gain ATI3 —> ROH2 +10.5 +12.0 +13.5 dB ZIN-ATI3 Input Impedance ATI3 100 kΩ Receive characteristics ILine=15mA f=800Hz, unless other specified Symbol Parameter Conditions Min Typ Max Units AHRX Receive Gain LS —> ROH1 ZAC(syn)=1000Ω +1.0 +2.5 +4.0 dB AAR1X Receive Gain LS —> ROH2 ZAC(syn)=1000Ω +7.0 +8.5 +10.0 dB AAR1X Receive Gain LS —> ARO1 ZAC(syn)=1000Ω +0.7 +2.2 +3.7 dB ∆ARX Variation with frequency f=500Hz to 3.4kHz ±0.8 dB AVOL Volume control range -6/+8 dBr THD Distortion ROH1-ROH2 VLS=0.25VRMS THD Distortion ARO1 VLS=0.25VRMS VUFC Unwanted Freq. Comp. f = 200 … 20kHz -60 dBm VAGC Soft Clip Level ROH1 0.7 VP VAGC Soft Clip Level ROH2 1.4 VP ASCO Soft Clip Overdrive ROH1/2 dB tattack tdecay Attack time Decay time µs/6dB ms/6d B VNO Noise Output Voltage ROH1/2 - ARO1 TAMP=25°C -71 dBmp ZIN-RI VINmax Input Imp. RI Input Voltage Range RI kΩ Vp

Input Imp. STB Input Volt. Range STB kΩ Vp ST Sidetone VRI<=0.25VRMS dB RL ∆ZAC/°C Return Loss Temp. Variation ZAC(syn)=1000Ω 0.5 dB Ω/°C Test circuit

The device is available in the packages outlined below (not to scale). For exact mechanical package dimensions please see AMSAG packaging information. 28-pin plastic SOIC (suffix T) Max. Body Length 18.1mm / 713mil Max. Body Width 7.6mm / 300mil Pitch 1.27mm / 50mil Pin-out 1 – M3 – 2 – M4 – 3 – CS LLC – 4 – VSS MASK – 5 – LI ATI1 – 6 – RI ATI2 – 7 – LS HSS – 8 – ROH1 RX0 – 9 – ROH2 TX0 – 10 – ARO1 TX1 – 11 – VDD AUX0 – 12 – AGND AUX1 – 13 – STB VOL – 14 – CI ATI3 – Marking YYWWAAA AS2504 Austria YY year of production WW calendar week of production AAA AMSAG assembly ID

Ordering information

Description

plastic small outline package - 28 leads (suffix T) Devices sold by Austria Mikro Systeme Int. AG are covered by the warranty and patent idemnification provisions appearing in its Term of Sale. Austria Mikro Systeme Int. AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the decribed devices from patent infringement. Austria Mikro Systeme Int. AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Austria Mikro Systeme Int. AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equiment are specifically not recommended without additional processing by Austria Mikro Systeme Int. AG for each application. Copyright © 1997-98, Austria Mikro Systeme International Int. AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria- Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished here by Austria Mikro Systeme Int. AG is believed to be correct and accurate. However, Austria Mikro Systeme Int. AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Austria Mikro Systeme Int. AG rendering of technical or other services. Headquarters Austria Mikro Systeme International Int. AG Schloß Premstätten

8141 Unterpremstätten, Austria-Europe

Tel: +43 (0)3136 500-0 Fax: +43 (0)3136 52501, 53650 email: info@vertical-global.com http://www.vertical-global.com France

124 Avenue de Paris

Tel:+33 (0)1 4374 0090 Fax: +33 (0)1 4374 2098 Germany (south) Stefan-George-Ring 19 D-81929 München Tel: +49 (0)89 993 558-0 Fax: +49 (0)89 993 558-66 Germany (nord) Am Seestern 8 D-40547 Düsseldorf Tel: +49 (0)211 536 02-0 Fax: +49 (0)211 536 02-50 Hong Kong 21/F., 1 Des Voeux Road West Sheung Wan, Hong Kong Tel: +852 2524 2738 Fax: +852 2868 4155 Italy Piazzale Lugano 9 I-20158 Milano Tel: +39 02 3932 1022 Fax: +39 02 3932 3087 Spain Parc Tecnològic del Vallès E-08290 Cerdanyola/Barcelona Tel: +34 (0)93 582 4470 Fax: +34 (0)93 582 4471 Sweden (Scandinavia) Sjöängsvägen 7 S-19272 Sollentuna Stockholm Tel: +46 (0)8 7549 395 Fax: +46 (0)8 7544 544 United Kingdom Coliseum Business Centre Watchmoor Park Camberley, Surrey England GU15 3YL Tel: +44 (0)1276 233 99 Fax: +44 (0)1276 293 53 USA Suite 460 20863 Stevens Creek Blvd. Cupertino, CA 95014 Tel: +1 408 865 1217 Fax: +1 408 865 1219 Austria Mikro Systeme Int. AG is represented by distributors in the following countries. Please contact your nearest regional sales office for the distributor’s address: China, India, Japan, Korea, Singapore, Taiwan Application support Please contact your local sales office or your distributor

Product Information

AS2504 specifications and overview.

Summary

Cordless telephone, answering machine line interface

Description

Cordless telephone, answering machine line interface

Source title AS2504 Datasheet(PDF) - ams AG

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