BL34118

BL34118 Voice Switched Speakerphone Circuit BL34118 The BL34118 Voice Switched Speakerphone Circuit incorporates the necessary amplifiers, attenuators, level detectors, and control algorithm to form the heart of a high quality hands-free speakerphone system. Included are a microphone amplifier with adjustable gain and MUTE control, Transmit and Receive attenuators which operate in a complementary manner, level detectors at both input and output of both attenuators, and background noise monitors for both the transmit and receive channels. A Dial Tone Detector prevents the dial tone from being attenuated by the Receive background noise monitor circuit. Also included are two line driver amplifiers, which can be used to form a hybrid network in conjunction with an external coupling transformer. A high-pass filter can be used to filter out 60Hz noise in the receive channel, or for other functions. A chip Disable pin permits powering down the entire circuit to conserve power on long loops where loop current is at a minimum. The BL34118 may be operated from a power supply, or it can be powered from the telephone line, requiring typically 5.0 mA. The BL34118 can be interfaced directly to Tip and Ring (through a coupling transformer) for stand-alone operation, or it can be used in conjunction with a handset speech network and/or other features of a feature phone. Improved Attenuator Gain Range: 52 dB Between Transmit and Receive Low Voltage Operation for Line-Powered Applications (3.0 – 6.5V) 4-Point Signal Sensing for Improved Sensitivity Background Noise Monitors for Both Transmit and Receive Paths Microphone Amplifier Gain Set by External Resistors – Mute Function Included Chip Disable for Active/Standby Operation On Board Filter Pinned-Out for User Defined Function Dial Tone Detector to Inhibit Receive Idle Mode During Dial Tone Presence Standard 28-Pin Plastic DIP Package and SOIC Package Available Compatible with BL34119 Speaker Amplifier PIN CONNECTIONS( Top View ) FO FI CD Vcc HTO+ HTOHTI TXO TXI MCO MCI MUT VLC CT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND CPR RLI1 RLO1 TLO1 TLI1 RXO RXI RLI2 RLO2 TLO2 TLI2 CPT VB http://www.belling.com.cn -1- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 PIN DESCRPTION Pin 1 2 3 Name FO FI CD Description Filter output. Output impedance is less than 50 ohms. Filter input. Input impedance is greater than 1.0 Mohm. Chip Disable. A logic low (2.0V) disables the IC to conserve power. Input impedance is nominally 90 kΩ. 4 VCC A supply voltage of +2.8 to +6.5 volts is required, at AGC circuit reduces the receive attenuator gain by ≈ 5.0 mA. As Vcc falls from 3.5 to 2.8 volts, an ≈ 25 db (when in the receive mode). 5 HTO+ Output of the second hybrid amplifier. The gain is internally set at –1.0 to provide a differential output, in conjunction with HTO-, to the hybrid transformer. 6 7 8 9 10 11 12 HTOHTI TXO TXI MCO MCI MUT Output of the first hybrid amplifier. The gain of the amp is set by external resistors. Input and summing node for the first hybrid amplifier. DC level is Output of the transmit attenuator. DC level is approximately VB. Input to the transmit attenuator. Max. signal level is 350 mVrms. Input impedance is ≈ VB. ≈ 10 kΩ. Output of the microphone amplifier. The gain of the amplifier is set by external resistors. Input and summing node of the microphone amplifier. DC level is ≈ VB. Mute input. A logic low (2.0V) mutes the microphone amplifier without affecting the rest of the circuit. Input impedance is nominally 90 kΩ. 13 VLC Volume control input. When VLC = VB, the receive attenuator is at maximum gain when in the receive mode. When VLC = 0.3VB, the receive gain is down 35 dB. Does not affect the transmit mode. 14 15 CT VB An RC at this pin sets the response time for the circuit to switch modes. An output voltage ≈ Vcc/2. This voltage is a system as ground, and biases the volume control. A filter cap is required. 16 17 18 CPT TLI2 TLO2 An RC at this pin sets the time constant for the transmit background monitor. Input to the transmit level detector on the mike/speaker side. Output of the transmit level detector on the mike/speaker side, and input to the transmit background monitor. 19 20 21 RLO2 RLI2 RXI Output of the receive level detector on the mike/speaker side. Input to the receive level detector on the mike/speaker side. Input to the receive attenuator and dial tone detector. Max input level is 350 mVrms. Input impedance is 22 23 24 25 26 27 28 RXO TLI1 TLO1 RLO1 RLI1 CPR GND ≈ 10 k Ω . Output of the receive attenuator. DC level is approximately VB. Input to the transmit level detector on the line side. Output of the transmit level detector on the line side. Output of the receive level detector on the line side, and input to the receive background monitor. Input to the receive level detector on the line side. An RC at this pin sets the time constant for the receive background monitor. Ground pin for the entire IC. http://www.belling.com.cn -2- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 BLOCK DIAGRAM Microphone Tx Attenuator ZB Tip Mute Background Noise Monitor AGC Level Detectors Attenuator Control Level Detectors Background Noise Monitor -1.0 Ring Vcc Bias Speaker Rx Attenuator Power Amplifier Volume Control Dial Tone Detector Chip Disable Filter ABSOLUTE MAXIMUM RATINGS Parameter Supply Voltage (Pin 4) Voltage at CD (Pin 3), MUT (Pin 12) Voltage at VLC (Pin 13) Voltage at TXI (Pin 9), RXI (Pin21), FI (Pin 2) Storage Temperature Range Value -1.0, +7.0 -1.0, Vcc + 1.0 -1.0, Vcc + 0.5 -0.5, Vcc + 0.5 -65 to +150 Units Vdc Vdc Vdc Vdc ºC RECOMMENDED OPERATING LIMITS Parameter Supply Voltage (Pin 4) CD Input (Pin 3), MUT Input (Pin 12) IVB (Pin 13) VLC ( Pin 13) Attenuator Input Signal Voltage (Pins 9, 21) Microphone Amplifier, Hybrid Amplifier Gain Load Current @ RXO, TXO (Pins 8, 22) @ MCO (Pin 10) @ HTO-, HTO+ (Pins 6, 5) Ambient Operating Temperature Range Min 3.5 0 0.3xVB 0 0 0 0 0 -20 Typ - Max 6.5 Vcc 500 VB 350 40 Units Vdc Vdc µA Vdc mVrms dB mA ± 2.0 ± 1.0 ± 5.0 +60 °C http://www.belling.com.cn -3- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 ELECTRICAL CHARACTERISTICS (TA=+25°C, Vcc=5.0V, CD ≤ 0.8V, unless noted) Parameter Power Supply Vcc Supply Current (Vcc=6.5V, CD=0.8V) (Vcc=6.5V,CD= 2.0V) CD Input Resistance (Vcc=VCD=6.5V) CD Input Voltage – High _ Low VB Output Voltage (Vcc = 3.5V) (Vcc = 5.0V) VB Output Resistance (IVB = 1.0 mA) VB Power Supply Rejection Ratio (CVB = 220 uF, f = 1.0kHz) ROVB PSRR RCD VCDH VCDL VB Icc 50 2.0 0 1.8 5.5 600 90 1. 3 2.1 400 54 8.0 800 Vcc 0.8 2.4 Ω dB mA µA kΩ Vdc Vdc Vdc Symbol Min Typ Max Units ATTENUATORS (TA = +25°C) Receive Attenuator Gain (f = 1.0 kHz, VLC = VB) Rx Mode, RXI = 150 mVrms (Vcc = 5.0V) Rx Mode, RXI = 150 mVrms (Vcc = 3.5V) Gain Change – Vcc = 3.5V versus Vcc = 5.0V AGC Gain Change – Vcc = 2.8V versus Vcc = 5.0V Idle Mode, RXI = 150 mVrms Range (Rx to Tx mode) Volume Control Range (Rx Mode, 0.3VB < VLC < VB) RXO DC Voltage (Rx Mode) ∆RXO DC Voltage (Rx to Tx Mode) RXO High Voltage (Iout = - 1.0mA RXI = VB + 1.5V) RXO Low Voltage ( Iout = - 1.0 mA, RXI = VB – 1.0, Output measured with respect to VB) RXI Input Resistance (RXI < 350 mVrms) Transmit Attenuator Gain (f = 1.0 kHz) Tx Mode, TXI = 150 mVrms Idle Mode, TXI = 150 mVrms Range (Tx to Rx Mode) TXO DC Voltage (Tx Mode) ∆TXO DC Voltage (Tx to Rx Mode) TXO High Voltage (Iout = -1.0 mA TXI = VB +1.5V) TXO Low Voltage (Iout = +1.0 mA, TXI = VB – 1.0V, Output measured with respect to VB) TXI Input Resistance (TXI < 350 mVrms) Gain Tracking ( GRX + GTX, @ Tx, Idle, Rx) RTXI GTR 7.0 10 14 kΩ dB GTX GTXI ∆GTXI VTXO ∆VTXO VTXOH VTXOL +4.0 -22 49 3.7 +6.0 -20 52 VB +8.0 -17 54 Vdc mV Vdc Vdc RRXI 7.0 10 14 kΩ dB GRX GRX ∆GRX1 ∆GRX2 GRXI ∆GRX3 VCR VRXO ∆VRXO VRXOH VRXOL +4.0 +4.0 -0.5 -22 49 27 3.7 +6.0 +6.0 0 -25 -20 52 35 VB +8.0 +8.0 +0.5 -15 -17 54 dB Vdc mV Vdc Vdc dB ± 10 -1.5 ± 150 -1.0 ± 30 -1.5 ± 150 -1.0 ± 0.1 http://www.belling.com.cn -4- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 ATTENUATOR CONTROL (TA = +25°C) CT Voltage ( Pin 14 – VB) Rx Mode (VLC = VB) Idle Mode Tx Mode CT Source Current (switching to Rx mode) CT Sink Current (switching to Tx mode) CT Slow Idle Current CT Fast Idle Internal Resistance VLC Input Current Dial Tone Detector Threshold ICTR ICTT ICTS RFI IVLC VDT VCT -85 +40 1.5 10 +240 0 -240 -60 +60 0 2.0 -60 15 -40 +85 3.6 20 µA µA µA kΩ nA mV mV MICROPHONE AMPLIFIER (TA = +25°C, VMUT ≤ 0.8V, AVCL = 31 dB unless otherwise noted) Output Offset (VMCO – VB, Feedback R = 180 kΩ) Open Loop Gain (f < 100 Hz) Gain Bandwidth Output High Voltage (Iout = -1.0mA, Vcc = 5.0V) Output Low Voltage (Iout = +1.0mA) Input Bias Current (@ MCI) Muting (∆Gain) (f = 1.0KHz, VMUT = 2.0 V) (300 Hz < f < 10 kHz) MUT Input Resistance ( Vcc = VMUT = 6.5V) MUT Input – High MUT Input – Low Distortion ( 300 Hz < f < 10 kHz) RMUT VMUTH VMUTL THDM MCOVOS AVOLM GBW M VMCOH VMCOL IBM GMT -50 70 3.7 -55 50 2.0 0 0 80 1.0 -40 -68 90 0.15 +50 200 Vcc 0.8 kΩ Vdc Vdc % mVdc dB MHz Vdc mVdc nA dB HYBRID AMPLIFIER (TA = +25°C) HTO- Offset (VHTO- - VB, Feedback R = 51 kΩ) HTO- to HTO+ Offset (Feedback R = 51 kΩ) Open Loop Gain ( HTI to HTO-, f < 100 Hz) Gain Bandwidth Closed Loop Gain ( HTO- to HTO+) Input Bias Current ( @ HTI) HTO- High Voltage ( Iout = -5.0 mA) HTO- Low Voltage ( Iout = +5.0 mA) HTO+ High Voltage ( Iout = -5.0 mA) HTO+ Low Voltage ( Iout = +5.0 mA) Distortion ( 300 Hz < f < 10 kHz, See Figure 1) HVOS HBVOS AVOLH GBW H AVCLH IBH VHT-H VHT-L VHT+H VTH+L THDH -20 -30 60 -0.35 3.7 3.7 0 0 80 1.0 0 -30 0.3 +20 +30 +0.35 250 450 mVdc mVdc dB MHz dB nA Vdc mVdc Vdc mVdc % http://www.belling.com.cn -5- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 LEVEL DETECTORS AND BACKGROUND NOISE MONITORS (TA = +25°C) Transmit-Receive Switching Threshold ( Ratio of Current at RLI1 + RLI2 to 20 uA at TLI1 + TLI2 to switch from Tx to Rx) Source Current at RLO1, RLO2, TLO1, TLO2 Sink Current at RLO1, RLO2, TLO1, TLO2 CPR, CPT Output Resistance ( Iout = 1.5 mA) CPR, CPT Leakage Current ILSO ILSK RCP ICPLK -2.0 4.0 35 -0.2 mA µA Ω µA ITH 0.8 1.0 1.2 FILTER (TA = +25°C) Voltage Offset at FO (VFO – VB, 220 kΩ from VB to FI) FO Sink Current FI Bias Current FOVOS IFO IFI -200 150 -90 260 -50 0 400 mV µA nA SYSTEM DISTORTION (TA = +25°C) Rx Mode ( From FI to RXO, FO connected to RXI) Tx Mode ( From MCI to HTO-/HTO+, includes Tx attenuator) THDR THDT 0.5 0.8 3.0 3.0 % % 1. All currents into a devices pin are positive, those out of a pin are negative, Algebraic convention rather than magnitude is used to define limits. 51 K HTOVin 0.1 10 K HTI R 1200 ohm + VB X1 Instr. Amplifier R VB To Dist. Analyzer HTO+ + FIGURE 1 – HYBRID AMPLIFIER DISTORTION TEST http://www.belling.com.cn -6- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 FIGURE 2 – ATTENUATOR GAIN versus Vct FIGURE 3 – LEVEL DETECTOR DC TRANSFER CHARACTERISTICS OUTPUT CHANGE (mV) GAIN (dB) Vct – VB (mV) FIGURE 4 – LEVEL DETECTOR AC TRANSFER CHARACTERISTICS OUTPUT CHANGE FROM 1.0kHz(mV) DC INPUT CURRENT (uA) FIGURE 5 – LEVEL DETECTOR AC TRANSFER CHARACTERISTICS versus FREQUENCY OUTPUT CHANGE (mV) INPUT SIGNAL (mVrms) FIGURE 6 – RECEIVE ATTENUATOR versus VOLUME CONTROL GAIN (dB) VLC / VB http://www.belling.com.cn -7- F, FREQUENCY (Hz) FIGURE 7 – RECEIVE ATTENUATION GAIN versus Vcc GAIN CHANGE (dB) Vcc (VOLTS) 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 FIGURE 8 – MICROPHONE AMPLIFIER AND 1 HYBRID AMPLIFIER OPEN LOOP GAIN AND PHASE INPUT CURRENT (uA) st FIGURE 9 – INPUT CHARACTERISTICS @ CD, MUT INPUT VOLTAGE (VOLTS) FIGURE 10 – SUPPLY CURRENT versus SUPPLY VOLTAGE FIGURE 11 – VB OUTPUT CHARACTERISTICS FIGURE 12 – VB POWER SUPPLY REJECTION versus FREQUENCY AND VB CAPACITOR FIGURE 13 – POWER SUPPLY REJECTION OF THE MICROPHONE AND HYBRID AMPLIFIERS http://www.belling.com.cn -8- 8/15/2006 Wrote by 2006 Total 11 Pages BL34118 FIGURE 14 – TYPICAL OUTPUT SWING versus Vcc TEMPERATURE CHARACTERISTICS Parameter Vcc Supply Current (CD = 0.8 V) Vcc Supply Current (CD = 2.0 V) VB Output Voltage (Vcc = 5.0 V) Attenuator gain (Max Gain ) Attenuator Gain (Max Attenuation) Attenuator Input Resistance (@ TXI, RXI) Dial Tone Detector Threshold CT Source, Sink Current Microphone, Hybrid Amplifier Offset Transmit-Receive Switching Threshold Sink Current at RLO1, RLO2, TLO1, TLO2 Closed Loop Gain (HTO- to HTO+) Typical Value @ 25 °C 5.0 mA 400 µA 2.1 V +6.0 dB -46 dB 10 kΩ 15 mV Typical Change –20 to +60 °C - 0.3 %/°C -0.4 %/°C +0.8 %/°C 0.0008 dB/°C 0.004 dB/°C + 0.6 %/°C +20 µV/°C -0.15 %/°C ± 60 µA 0 mV 1.0 4.0 µA 0 dB ± 4.0 µV/°C ± 0.02 %/°C -10 nA/°C 0.001 %/°C http://www.belling.com.cn -9- 8/15/2006 Wrote by 2006 Total 11 Pages http://www.belling.com.cn APPLICATION CIRCUIT ASSEMBLY PACKAGE DIMENSION Vcc 20uF VB 0.2 270pF 0.1 5.1k RHI 10k 0.1 5.1k 300 0.1 0.05 51k RHF 5.1k 180k RMF 0.1 Mike 0.02 Hook Switch 820 Tip MCI 11 MCO 10 17 TLI2 TXI 9 Tx Attenuat or TXO 8 TLI1 23 7 HTI - 6 HTO- 0.01 - Ring + Vcc Mute MUT 12 VB R R + VB VB VB Vcc VB HTO+ 5 Vcc 4 CD 3 TLO1 24 1000uF 2.0uF 100k Vcc + + AGC + - - + VB - + Total 11 Pages Wrote by 2006 2.0uF Vcc 100k 47uF TLO2 18 CPT 16 RLO2 2.0 19 uF - 10 8/15/2006 BNM Attenuator Control BNM CPR 27 RLO1 25 2.0uF 47uF Disable 1N4733 5.1V CT 14 5.0uF 120k DTD + VB VB - GND 28 Filter VB 220k 4700u F VB 15 220uF Rx Attenuat or FI +1 2 5.1k 110k 0.05 200pF RLI2 20 RXO 22 VLC 13 20k 9.1k 21 RXI 0.1 26 RLI1 0.05 10k FO 1 56k VB 10k 0.1 Volume Control 5 RL 4 BL34119 3 VB 1 8 BL34118 7 6 BL34118 Unit: inches (mm) SOP 28 http://www.belling.com.cn - 11 - 8/15/2006 Wrote by 2006 Total 11 Pages