U4087B Low Voltage Voice Switch Interface Circuit for Hands-free Operation in Telephone Description The voice switch interface circuit U4087B is a linear integrated circuit for improvement of handsfree performance of U4090B system. Additionally, the U4087B provides a back- ground noise monitor which makes the circuit insensitive to room noise. The Block diagram shows level detectors, back ground noise monitor. The U4087B provides an optimized interface to U4090B, the necessary level detectors and switching control for a properly operating speakerphone. The detection sensitivity and timing are externally controllable. Due to low voltage operation it can be operated via power supply management of U4090B requiring 1.0 mA typ. Features Benefits D D D D D Low voltage operation: 3.0 to 7.0 V D Fast channel switching allows quasi duplex operation Four point signal sensing D Low current consumption Monitoring system for background noise level Case: SO 16 Chip Disable for active/standby operation Block Diagram TLO2 CPT 16 TLI2 15 VB 14 7 Noise detector Logic = VM CD GND 13 6 5 – + Logic 9 DIRE DIRA RLO2 TLI1 – + Discharge C.T. Generator Logic 8 1 TS Charge RLI2 2 Bias Logic + – TLO1 12 CT Logic 10 11 TLDR TLDT 4 RLI1 3 RLO1 12610 Figure 1. Block diagram with external circuit TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 1 (8) Preliminary Information SAO MICO C9 47 nF C 10 100 nF 8.2 k W R4 3.6 k W R5 RLI2 TLI2 9 15 mF Logic Logic TLO2 15 C2 2 (8) Preliminary Information mF C8 2.2 16 mF 4.7 mF CT C7 Charge DIRA TS RLO2 – + 7 VB 12 14 300 k W R1 8 + – = Noise detector CPT 15 C2 VB 6 TLDR DIRE 2.2 mF RLO1 TLDT Logic Logic 3 C6 – + 2 TLO1 mF C3 2.2 11 Discharge 5 GND TLDT TLDR 10 C.T. Generator Logic Bias 13 GND CD CD VM VM 12611 4 1 RLI1 TLI1 100 nF 47 nF 30 k W C 5 R3 5.1 k W C 4 R2 RECO ST U4087B Figure 2. Application for hands-free operation TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 R29 R18 Preliminary Information 95 9679 R15 R14 C14 C15 24 22 12 26 TLDT 27 28 42 2 29 C16 33 8 21 31 7 10 R8 R4 11 C4 14 C5 13 C6 R13 23 R12 25 35 R11 40 Earpiece 36 VM C12 VM R9 C13 R 10 41 39 U4090B C11 STN 38 STIN 2 (Option) 37 C10 18 LOGTX VL 43 19 15 16 20 17 32 9 6 44 R3 4 3 to STIN 13 V R2 C3 34 1 C1 C2 5 30 C21 Micro– phone R26 R1 TLDR C24 C25 R16 R17 Loud speaker R22 VM R24 HF–Mic R23 C23 DTMF R25 VM R7 BC177 R21 VB R6 VM to m C C8 L1 Q1 C9 R5 Micro– controller 28 V hook switch Ring VMP C7 Tip U4087B Figure 3. Application for handsfree operation 3 (8) U4087B Typical Value of External Components C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 L1 R1 R2 100 nF 4.7 nF 10 mF 220 mF 47 mF 470 mF 820 nF 100 mF 100 nF 150 nF 68 nF 33 nF 10 mF 100 nF 1 mF 47 mF 10 mF 10 mF 68 nF 68 nF 1 mF 100 nF 6.8 nF 10 nF 100 nF 2.2 mH 27 kW 20 kW R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R31 4 (8) Preliminary Information > 68 kW 10 W 1.5 kW 62 kW 680 kW 22 kW 330 W 3 kW 62 kW 30 kW 62 kW 120 kW 47 kW 1 kW 1.2 W 30 kW 6.8 kW 6.8 kW 15 kW 330 kW 220 kW 68 kW 2 kW 3.3 kW 18 kW 2 kW 56 kW TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 U4087B Pin Description Pin 1 2 3 4 5 6 Symbol TLI1 TLO1 RLO1 RLI1 GND CD 7 8 9 10 11 12 VB RLO2 RLI2 TLDR TLDT CT 13 14 15 16 VM CPT TLI2 TLO2 Function Transmit level detector input on the line side Transmit level detector output on the line side Receive level detector output on the line side Receive level detector input on the line side Ground Chip Disable A logic low (< 0.8 V) sets normal operation. A logic high (> 2.0 V) disables the IC to conserve power. Input impedance is nominally 90 kW. Supply voltage 2.8 to 7.0 V, approx. @ 1 mA Receive level detector output on the microphone/speaker side Receive level detector input on the microphone/speaker side Positive control output for U4090B Negative control output for U4090B Response time An RC at this pin sets the response time for the circuit to switch modes It is a system ac ground, supplied by U4090B, VM VB/2 An RC at this pin sets the time constant for the transmit background monitor Transmit level detector input on the microphone/speaker side Transmit level detector output on the microphone/speaker side, and input to the transmit background monitor X Absolute Maximum Ratings Reference point Pin 1, Tamb = 25°C, unless otherwise specified Parameters Supply voltage Voltages: Unit V Tstg Tj Tamb Value – 0.3 to + 12 – 0.3 to 6 – 0.3 to (VB + 0.3) – 55 to + 150 125 – 20 to + 60 SO 16 Ptot 750 mW SO 16 RthJA 110 K/W Pin 7 Pin 6 Pin 13 Storage temperature range Junction temperature Ambient temperature range Power dissipation Tamb = 60 °C Maximum thermal resistance Junction ambient Symbol VB V °C °C °C Operation Recommendation Parameters Supply voltage CD input Pin 6 Ambient temperature range TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 Test conditions / Pin Pin 7 Symbol VB Tamb Min. 3.0 0 – 20 Typ. – – – Max. 7.0 VB + 60 Unit V V °C 5 (8) Preliminary Information U4087B Electrical Characteristics Tamb = + 25°C, VS = 5.0 V, CD Parameters Power supply Supply current CD input resistance CD input voltage Attenuator control CT voltage v 0.8 V unless otherwise specified , Test conditions / Pin VB = 6.5 V, CD = 0.8 V VB = 6.5 V, CD = 2.0 V VB = VCD = 6.5 V – High – Low Symbol IB RCD VCDH VCDL Pin 12 – VM R mode Idle mode T mode R mode T mode CT source current CT sink current CT idle current Level detectors and background noise monitor Source current at RLO1, RLO2, TLO1, TLO2 Sink current at RLO1, RLO2, TLO1, TLO2 CPT output resistance IO = 1.0 mA CPT leakage current Min. 50.0 2.0 0.0 Typ. Max. Unit 1.0 60.0 90.0 2.0 150.0 mA mA kW V VB 0.8 VCT ICTR ICTT ICTS – 85.0 + 40.0 + 240.0 0.0 – 240.0 – 60.0 + 60.0 0.0 mV – 40.0 + 85.0 mA mA mA ILSO – 2.0 mA ILSK 4.0 mA RCP ICPLK 100 – 0.2 W mA Ordering Information Type U4087B-FP Package SO16 6 (8) Preliminary Information TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 U4087B Dimensions in mm Package: SO16 94 8875 TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96 7 (8) Preliminary Information U4087B 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 8 (8) Preliminary Information TELEFUNKEN Semiconductors Rev. A1, 09-Sep-96