ICs for Telephone AN6426NK Hands-free Speech Network IC ■ Overview Unit : mm The AN6426NK incorporates both speech network and hands-free functions. Its well designed block configuration allows realization of a hands-free telephone with a minimal number of components. 1 0.5±0.1 0.9±0.25 42 36.8±0.3 ■ Features • Incorporates all the functions required of a hands-free telephone. • Incorporates all the functions required of a handset. • Complies with AC and DC impedance requirements. • Provides a wide dynamic range. • A noise detecting circuit prevents inadvertent transmission. • Operation on an external power supply is available. • Each mode can be easily controlled. • A built-in loudspeaker amplifier can operated either on line voltage or an external power supply. 21 22 13.7±0.3 0.96±0.25 4.5±0.25 4.76±0.25 +0.1 0.3 – 0.05 15.3±0.25 3 to 15° SDIP package with 42 pins (SDIP042-P-0600A) ■ Block Diagram VL 38 39 19 14 15 37 – Vrl +MA2 AP Buffer 41 VCC1 42 Send 36 VCC2 34 Power Regulator 29 Power Regulator GND 6 5 35 Power Regulator Matrix Circuit 40 Vrl + 12 MA1 – 1 33 32 VB TATT VB T Log 18 + 16 – – + + 31 Matrix Circuit 13 30 Vr1 VCC1 20 – 17 21 24 28 VB R Log 22 Attenator Control Comp 23 27 AGC Vrl Rec Pre 11 Vr1 – AP 10 – Rec.2 + Rec.1 + Buffer 9 7 8 – S.Amp + Vr1 2 3 VB Vr2 RATT 26 4 25 1 ICs for Telephone AN6426NK ■ Pin Descriptions Pin No. Symbol 1 GND Ground 22 AC 2 AGC Loudspeaker amp. time constant 23 RAC Receiver att. control 3 SAO Loudspeaker amp. output 24 RVR To receiver rheostat 4 SAI Loudspeaker amp. input 25 RAO Receiver att. output 5 Vr2 Reference voltage (2) 26 RAI Receiver att. input 6 VPO Loudspeaker amp. power supply 27 RLO Receiver LOG amp. output 7 RO1 Receiver output (1) 28 RLI Receiver LOG amp. input 8 RO2 Receiver output (2) 29 VCC2 Supply voltage (2) 9 RBO Receiver buffer output 30 Mute (R) Receiver mute 10 RPO Receiver preamp. output 31 HSu/SPu HS/HF switching 11 RPI Receiver preamp. input 32 Mute (S) Transmitter mute 2 Description Pin No. Symbol Description Att. control 12 MAI1 MIC amp. input (1) 33 APC Auto. PAD control 13 MAO1 MIC amp. output (1) 34 Vr1 Reference voltage (1) 14 TL1 Transmitter LOG amp. input 35 VB Reference voltage 15 TLO Transmitter LOG amp. output 36 VCC Supply voltage (1) 16 ND1 Noise detection time constant (1) 37 MAO2 MIC amp. input (2) 17 ND2 Noise detection time constant (2) 38 MAO2 MIC amp. output (2) 18 TAI Transmitter att. input 39 TSI 19 TAO Transmitter att. output 40 20 ATC Att. timing control 41 S0 Transmitter output 21 TAC Transmitter att. control 42 VL Line voltage Transmitter signal input MFI MF MF signal input ICs for Telephone AN6426NK ■ Absolute Maximum Ratings (Ta=25˚C) Symbol Rating Supply voltage Parameter VL 14.4 Unit V Supply current IL 120 mA mW Power dissipation (Ta = 60˚C) PD 1700 Operating ambient temperature Topr –20 to + 60 ˚C Storage temperature Tstg –55 to +150 ˚C Note) The IC must be used under the condition PD>VCC × ICC. ■ Recommended Operating Range (Ta=25˚C) Parameter Operating supply voltage range Symbol Range VL 3V to 12V ■ Electrical Characteristics (Ta=25˚C) Parameter Symbol Condition min typ max Unit Power Supply DC line voltage (1) VL (1) Voltage at Pin42 with IL=20mA 3.6 4.2 5.2 V DC line voltage (2) VL (2) Voltage at Pin42 with IL=120mA 9.0 11.0 12.0 V Int. supply voltage (1) VCC (1) Voltage at Pin36 with IL=20mA 1.8 2.3 2.8 V Int. supply voltage (2) VCC (2) Voltage at Pin36 with IL=120mA 6.0 7.0 9.0 V Int. regulated voltage (1) VB (1) Voltage at Pin35 with IL=20mA 0.95 1.10 1.35 V Int. regulated voltage (2) VB (2) Voltage at Pin35 with IL=120mA 1.10 1.20 1.45 V ni=–60dBm 36 39 42 dB nO=4dBm fi=1kHz, 7, 8 ni=–25dBm fi=1kHz, 7, 8 nO=5dBm Gain difference with 7, 8 ni=–60dBm as IL changes between 30 and 80mA 4 7 10 dBm 3 6 9 dB 5 8 11 dBm –8 –6 –4 dB HSU Receiver input pin output pin Rec. gain GR 11 Max. rec. level VR 11 MF rec. gain GMR 40 MF max. rec. level VMR 40 AP (R) characteristics DGR 11 Trans. gain GS 37 42 ni=–25dBm 26 29 32 dB Max. trans. level VS 37 42 nO=2.5dBm 2.5 5.5 8.5 dBm MF trans. gain GMS 40 42 22 25 28 dB MF max. trans. level VMS 40 42 1 4 7 dBm AP (S) characteristics DGS 37 42 –6 –4 0 dB Att. rec. gain GARR 26 25 –6.5 –3.5 – 0.5 dB Att. trans. gain GART 26 25 –38 –33 –28 dB Loudspeaker amp. (1) VOSP (1) 4 3 –10 –5 dBm Loudspeaker amp. (2) VOSP (2) 4 3 –4 1 dBm Loudspeaker amp. (3) VOSP (3) 4 3 0 4 dBm VV 26 25 –28 –25 7, 8 7, 8 HSU Transmitter fi=1kHz, ni=–25dBm fi=1kHz, nO=1dBm Gain difference with ni=–25dBm as IL changes between 30 and 80mA SPU Receiver Rheostat characteristics (1) ni=–20dBm ni=–20dBm, I20=14µA T12–T11 Value VPO=3V, THD=5% VPO=5V, THD=5% VPO=7V, THD=5% V24=V35, ni=–20dBm, IL=60mA –22 dBm 3 ICs for Telephone AN6426NK ■ Electrical Characteristics (cont.) (Ta=25˚C) Parameter Symbol Condition Rheostat characteristics (2) DGV 26 LOG amp. linearity LR IL=60mA, Ii=–1µA to –300µA SPU Transmitter min V24=0V, ni=–20dBm, IL=60mA 25 typ max –17 –27 –22 GMAI 12 13 MIC amp. max. output VMAI 12 13 Trans. gain GTS 39 42 Max. trans. level VTS 39 42 Att. trans. gain GATT 18 19 DGATR 18 19 VId 18 19 Att. rec. gain Idling ni=–60dBm IL=60mA IL=60mA THD=5% ni=–25dBm IL=60mA IL=60mA THD=10% ni=–20dBm IL=60mA ni=–20dBm IL=60mA ni=–20dBm IL=60mA IL=60mA Ii= –1µA to –300µA Note) Unless otherwise specified, fi=1kHz, IL=30mA(HSU), 60mA (SPU). LOG amp. linearity 40 50 32 35 38 dB 1 4 7 dBm 17 20 23 dB 4 7 10 dBm –2.5 0.5 3.5 dB –34 –29 –24 dB –18 –15 –12 dB 40 50 dB LT dB ■ Application Circuit MFIN DPin D.B. R21 100kΩ R29 ZNR 100kΩ 390V Q2 C18°0.1µF Q6 R23 SW C26 + R18 a 680Ω R24A 100kΩ 220µF R21 2.2kΩ 12kΩ R16 R20 0.068µF C17 C28 S3 2.2 C25 43kΩ 33 0.039µF + MΩ + C24 220 + + S2 a b + µF 0.001 C19 220 6.8 µF 1µF µF µF C21 a b kΩ C23 b R28 20kB C22 47µF R19 33Ω R28A R15 C20 C33 D4 C34 0.1 4.7 C18 10 µF R17 µF 10 D5 20Ω 2.2 + µF µF 5.1 1µF kΩ Z R14 R13 kΩ R22 27 22kΩ kΩ R27 R26 330Ω 3.3kΩ R132 1MΩ R31 680Ω R36 100kΩ D3 b MIC(HSU) R25 3.9kΩ Q1 L2 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 14 15 16 17 18 19 20 21 AN6426NK 2 4 5 6 7 C3 + 220 µF C2 10 µF Q3 220 kΩ R1 R35 10Ω C30 C31 + 1000µF + 100µF + 100µF C32 C1 10µF + 8 9 3300 pF C7 C5 0.033µF + C4 100µF 1kΩ 1kΩ R24 10kΩ D1 R2 R3 GND 100mA 3 C6 0.033µF 1 D6 AC Adaptor a 10 11 12 CS(HSU) Note) The circuit a applies when a ceramic receiver is used. When a dynamic receiver is used, the following circuits apply. 7 C5 0.033µF 8 + 10µF CS (HSU) C6 C6 0.033µF 13 C9 1µF 820 C14 R4 pF R6 C11 390 22 220 1µ Ω kΩ kΩ F R8 C27 R10 820Ω 22µF 100 C15 + kΩ 2.2µF R7 R5 1kΩ + C12 + R11 + C8 C10 1µ 220 0.1µF 1µF F R9 kΩ 2.2 MΩ R37 2.2kΩ SP(SPU) 4 dBm Input pins Output pins MIC amp. gain L1 Unit MIC(SPU) + R10 5.1 kΩ SW6 C16 2.2 µF R12 22kΩ ICs for Telephone AN6426NK ■ Pin Descriptions 1. Hand Set Communications Block (HSu) [ Transmitter System] Microphone amplifier Input : pin3 (minus input), Output : Pin38 (collector output) The gain and frequency characteristics are determined by the external resistors R19 (6.8kΩ)and R20 (43kΩ), and capacitors C24 (0.068µF)and C25 (1,000pF). R21 (2.2kΩ)is a resistor for the power supply for ECM. 37 38 Transmitter selector switch Input : Pin39 (speech), Pin40 (MF, holding tone) The switch changes over transmitter input for hand set communications, transmitter input for hand-free communications, and MF (Multi Frequency) input. The input impedance at the Pin39 is 3.9kΩ and DC is VR (Pin34) C33 (4.7µF) is a DC preventive capacitor. R22 (33kΩ) is to adjust the input to the log amplifier. which is to detect the transmission level. It attenuates the amplifier input to 3.9/(3.9+R22 (33kΩ) The input impedance at the Pin40 is 3.35kΩ and DC is VR. C34 is input through 10µF. 39 33 [Receiver System] Receiver preamplifier Input : Pin11(minus input), Output : Pin10 (collector output) The gain and frequency characteristics are determined by the external resistors R5 (1kΩ)and R4 (22kΩ), and capacitors C8 (0.1µF)and C7 (3,300pF) 11 10 Receiver selector switch Input : Pin10, Pin40 The switch changes over receiver input for hand set communications and MF input. Receiver automatic pad Control : Pin33 Common with transmitter automatic pad Receiver buffer amplifier Output : Pin9 Outputs a receiver signal for hand-free communications at low inpedance. 40 9 Transmitter automatic pad Control : Pin33 Varies the transmitter/receiver gain by the value of the current supplied to the IC. A variable point can be moved by R18 (100kΩ). Increasing R18 causes AP to start operation at a higher line current. 5 ICs for Telephone AN6426NK ■ Pin Descriptions (cont.) Receiver output Output : Pin7, Pin8 Drives the ceramic receiver directly. The gain depends on an internal resistance and is about 23dB. The frequency characteristic control capacitors C5 (0.033µF) and C6 (0.033µF), and output level control resistors R2(1kΩ)and R3 (1kΩ)are attached. 16 14 28 8 17 15 27 + – 7 24 2. Hand-free Speech network Block (SPU) [Transmitter System] Microphone amplifier Input : Pin12(minus input), Output : Pin13(emitter output) The gain and frequency characteristics are determined by the external resistors R7(820Ω)and R6(47kΩ), and capacitors C10 (1µF) and C9 (820pF). R37 (2.2kΩ) is a resistor for the power supply to ECM. 13 12 Transmitter log amplifier Input : Pin14(current input), Output : Pin15 (voltage output) The input voltage is converted into a current at R8(390Ω)and C11 (0.1µF). The attack and recovery time are determined by R9 (2.2MΩ)and C12(1µF). Receiver log amplifier Input : Pin28 (current input), Output : Pin27 (voltage output) The input voltage is converted into a current at R17 (2.2kΩ)and C20 (0.1µF). The attack and recovery time are determined by R16 (2.2MΩ)and C19 (1µF). 6 Noise detector circuit Output : Pin16, Pin17 When a continuous sound (noise 9) is input, the transmitter is set to –10dB. The attack time for this operation is determined by R10 (100kΩ)and C27 (22µF), and the recovery time by R11(220kΩ)and C15 (2.2µF). To stop the noise detector circuit, ground the Pin16. Receiver VR Control : Pin24 A smoothed voltage is given by C17 (33µF). Normally, VB (Pin35) is divided and given by R15 (20kΩ). The output becomes maximum when the voltage at the Pin24 is VB, and –31dB when 0V. Transmitter attenuator Input : Pin18 (Zi=15kΩ), Output : Pin19 (emitter output) The input is of only AC component due to C14 (1µF). At transmission time, an attenuation amount is varied within a range of about 0 to –36dB by the Gilbert circuit. The Pin18 is 15kΩ and connected to the VB Pin (1.2V) ICs for Telephone AN6426NK ■ Pin Descriptions (cont.) Receiver attenuator Input : Pin26 (Zi=15kΩ), Output : Pin25 (emitter output) The input is of only AC component due to C18 (1µF). At transmission time, an attenuation amount is varied within a range of about 0 to –36dB by the Gilbert circuit. The Pin25 is 15kkΩ and connected to the VB pin (1.2V). 18 19 Attenuator timing control (TAC) Control : Pin20 Controls the transmitter/receiver attenuator switching speed with C16(2.2µF). V20–29 ≈ 0V in the transmitter mode, and V20–29 ≈ –120mV in the receiver mode. Transmitter attenuator control (TAC) Control : Pin21 Controls the transmitter attenuator gain with R12(22kΩ). Receiver attenuator control (RAC) Control : Pin23 Controls the receiver attenuator gain with R13 (22kΩ). Transmitter/receiver attenuator control (AC) Control : Pin22 Controls the transmitter/receiver attenuator gain with R14 (27kΩ). 26 25 20 [Control System] High level ; 1 to 5V, Low level ; 0 to 0.5V Controllable with the microcomputer. HSU/SPU selector switch Control : Pin30 High : HSU, Low : SPU Transmitter mute switch Control : Pin32, High : Transmission, Low : Mute (MF transmission) Receiver mute switch Control : Pin30, High : Reception, Low : Mute (MF reception) 21 22 23 Speaker amplifier Input : Pin4, Output : Pin3, AGC : Pin2 Plus input amplifier of about 34 dB and driven at 25Ω. The input is of only AC component due to C3 (10µF). The output drives the 25Ω speaker througt C2 (220µF). The attack time and recovery time for AGC is determined by C1 (10µF) and R1(220kΩ). 6 2 4 Logic Circuit 3 5 30 31 32 7 ICs for Telephone AN6426NK ■ Pin Descriptions (cont.) 3. Power Supply Block HSU voltage source (VCC1) Stabilized by the Pin36 and C22 (220µF). HSU reference voltage (Vr1) Results in VCC/2 by resistance division (20kΩ)from the Pin34 and VCC, and stabilized by C22 (220µF) Constant voltage source (VB) Results in 1.2V by the Pin35 (band gap reference). Stabilized by C23 (220µF) Ground pin (GND) Pin1 (common with the GND pin of the speaker amplifier) Speaker amplifier voltage source (VPO) Pin6. It is necessary to stabilize the power supply in order to prevent a receiver signal from leaking to the circuit.(R34, C30, D1, Q3, C31, R35, C32, Q4) An AC adapter is available. (Q5, R33, D2, S5) Speaker amplifier reference voltage (Vr2) Pin5 (VCC2/2) Stabilized by C4 (100µF) 42 6 Bandgap reference 35 34 4. Other Circuit Blocks Balance network circuit Prevents howling. (R25, R26, R24, C28, R27, R28) Telephone circuit connection circuit Determines the polarity of the telephone circuit. (DB, R30, Q1, R32, R29, Q2, R31, C29) SPU voltage source (VCC2) The Pin29 (normally connected to VCC Pin1) is stabilized by C21 (100µF). A voltage can be applied from the outside. (S4, Q6, R36, D3, S1) 29 42 36 41 1 ■ Supplementary Explanation • Electrical Characteristics Design Reference Values (Ta=25°C) Parameter Symbol Condition typ max Unit 450 610 750 Ω AC Impedance (1) Zac (1) AC Impedance (2) Zac (2) HSU IL=90mA, f=1kHz 450 610 750 Ω AC Impedance (3) Zac (3) SPU IL=20mA, f=1kHz 450 610 750 Ω Note) The above characteristics are design reference values and not guaranteed values. 8 min HSU IL=20mA, f=1kHz ICs for Telephone AN6426NK ■ Characteristics Curve Handset Receiver I/O Characteristics VL — IL 8 6 4 2 0 –10 –20 –30 IL=40mA f=1kHz –40 0 20 40 60 80 100 –50 –70 120 –60 –50 –40 –30 –20 Handset Transmitter Automatic Pad Characteristics Transmitter Output υ 4—2 (dB) 6 4 2 0 –2 –4 –6 υi=25dBm f=1kHz 0 20 40 60 80 100 120 0 Circuit Current IL (mA) 20 40 Attenuation (dB) Receiver ( υ 25) Mic in Transmitter out Trabsnutter ( υ 19) 0 20 40 60 80 100 DV (VCC—VATC) (mV) 120 ,,,,,,,,,,, ,,,,,,,,,,, ,,,,,, ,,,,,, ,,,,,,, ,,,,,,, ,,,,,,, ,,,,,,, Speaker out 0 –30 100 –30 40ms –50 –40 –30 –20 –10 (dB) 200 150 100 50 0 –50 – 0.1 –1 –10 –100 Log Amplifier Input Current (µA) PD—Ta (IC Singular) 1 VPP 20mVPP 2 VPP (1880mW) 2000 10mVPP 1000 0 120 – 60 Log Amplifier Characteristics for Hands-free Speech Network Hands-free Speech network Transmitter/Receiver Switching Receiver in –20 80 Circuit Current IL (mA) Hands-free Speech network Transmitter Receiver Switching –10 60 –20 Microphone Input υ 37 Log Amplifier Output Voltage Change Amount DVO (mV) Handset Receiver Automatic Pad Characteristics –30 –10 –50 –70 –10 Receiver Input ( υ 11) (dB) –20 0 –40 Circuit Current IL (mA) υi= 60dBm f=1kHz Receiver Output υ 7—8 (dB) 0 Power Dissipation PD (mW) Circuit Voltage VL (V) 10 10 Transmitter Output υ 42 (dB) Receiver Output υ 7—8 (dB) 10 Handset Transmitter I/O Characteristics 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) 9