UNISONIC TECHNOLOGIES CO., LTD TEA1110A LINEAR INTEGRATED CIRCUIT LOW VOLTAGE VERSATILE TELEPHONE TRANSMISSION CIRCUIT WITH DIALLER INTERFACE SOP-14 DESCRIPTION The UTC TEA1110A is a versatile telephone transmission circuit providing full speech and line interface functions in electronic telephone sets. This device works at a line voltage which can be as low as 1.6V DC (with reduced performance) to enable parallel connection of telephone sets. It also realizes electronic switching between speeches and dialling. The UTC TEA1110A is ideal for applications, such as line powered telephone sets, cordless telephones, and fax machines, answering machines. DIP-14 FEATURES * Low DC line voltage; operates down to 1.6V (excluding voltage drop over external polarity guard) * Voltage regulator with adjustable DC voltage * Provides a supply for external circuits * Symmetrical high impedance inputs (64kΩ) for dynamic, magnetic or piezo-electric microphones * Asymmetrical high impedance input (32kΩ) for electric microphones * DTMF input with confidence tone * MUTE input for pulse or DTMF dialling * Receiving amplifier for dynamic, magnetic or piezo-electric earpieces * AGC line loss compensation for microphone and earpiece amplifiers. ORDERING INFORMATION Ordering Number Lead Free Halogen Free TEA1110AL-D14-T TEA1110AG-D14-T TEA1110AL-S14-R TEA1110AG-S14-R www.unisonic.com.tw Copyright © 2010 Unisonic Technologies Co., Ltd Package Packing DIP-14 SOP-14 Tube Tape Reel 1 of 9 QW-R108-014,C TEA1110A LINEAR INTEGRATED CIRCUIT PIN CONFIGURATION 14 VCC LN 1 SLPE 2 13 GAR REG 3 12 QR NC 4 11 VEE DTMF 5 10 MIC+ MUTE 6 9 MIC- IR 7 8 AGC PIN DESCRIPTION PIN NO. 1 2 3 4 5 PAD NO. 1 2 3 4 5 SYMBOL LN SLPE REG NC DTMF DESCRIPTION Positive line terminal Slope (DC resistance) adjustment Line voltage regulator decoupling Not connected Dual-tone multi-frequency input 6 6 MUTE Mute input to select speech or dialing mode (active LOW) 7 8 9 10 11 12 13 14 7 8 9 10 11 12 13 14 IR AGC MICMIC+ VEE QR GAR VCC Receiving amplifier input Automatic gain control/line loss compensation Inverting microphone amplifier input Non-inverting microphone amplifier input Negative line terminal Earpiece amplifier output Earpiece amplifier gain adjustment Supply voltage for internal circuit UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL RATINGS UNIT Positive Continuous Line Voltage VEE-0.4 ~ 12 V VLN Repetitive Line Voltage During Switch-on or V VEE-0.4 ~ 13.2 Line Interruption Maximum Voltage On All Pins VN(MAX) VEE -0.4 ~VCC+0.4 V Maximum Line Current (RSLPE=20Ω) ILINE 140 mA DIP-14 588 mW Power Dissipation (Ta=75°C) PD SOP-14 384 mW Junction Temperature TJ 125 °C Ambient Temperature TOPR -25~+75 °C Storage Temperature TSTG -40~+125 °C Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. THERMAL DATA PARAMETER Junction to Ambient SYMBOL DIP-14 SOP-14 θJA RATINGS 85 130 UNIT °C/W °C/W Note: Mounted on epoxy board ELECTRIC CHARACTERISTICS (Ta=25°C, unless otherwise specified) (ILINE=15mA, VEE=0V, RSLPE=20Ω, AGC pin connected to VEE, ZLINE=600Ω,f=1kHz) PARAMETER SYMBOL CONDITIONS Supplies (pins VLN, VCC, SLPE and REG) MIN TYP MAX UNIT Stabilized Voltage Between LN and SLPE 3.1 3.35 3.35 1.6 2.3 3.65 DC Line Voltage VREF VLN DC line voltage with an external resistor VLN(exR) RVA DC line voltage variation with VLN(T) temperature referred to 25 °C internal current consumption ICC Supply voltage for peripherals VCC Equivalent supply voltage resistance RCCint Microphone amplifier (pins MIC+ and MIC-) Voltage gain from MIC+/MIC- to LN GVTX Gain variation with frequency referred to GVTX(F) 1kHz Gain variation with temperature referred GVTX(T) to 25°C Common mode rejection ratio CMRR Maximum sending signal VLN(MAX) (RMS value) (rms) Noise output voltage at pin LN, pins VNOTX MIC+/MIC- shorted through 200Ω ILINE =1mA ILINE =4mA ILINE =15mA ILINE =140mA V 3.95 6.9 V V V V RVA(SLPE-REG) = 27kΩ 4.4 V Ta = -25 ~ +75 °C ±30 mV VCC = 2.9 V IP=0mA IP=0.5mA 1.3 2.9 550 1.48 620 mA V Ω 43.7 44.7 dB VMIC =4mV (RMS) 42.7 f =300~3400 Hz ±0.2 dB Ta =-25~+75 °C ±0.3 dB ILINE =15mA; THD=2% ILINE =4mA, THD=10% 80 1.7 0.8 dB V V -78.5 dBmp UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3.6 1.4 3 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT ELECTRIC CHARACTERISTICS(Cont.) PARAMETER SYMBOL CONDITIONS MIN Receiving amplifier (pins IR, QR and GAR) Voltage gain from IR to QR GVRX VIR = 4mV (RMS) 32 Gain variation with frequency referred to GVRX(F) f = 300~3400 Hz 1kHz Gain variation with temperature referred GVRX(T) Ta = -25 ~ +75 °C to 25°C external resistor connected between Gain voltage reduction range GVRXR GAR and QR IP =0mA sine wave drive RL = 50Ω, THD =2% Maximum receiving signal VO(rms) (RMS value) IP = 0mA sine wave drive RL =450 Ω, THD =2% Noise output voltage at pin R GVRX =33dB, IR open-circuit, VNORX(rms) (RMS value) RL =150Ω Automatic gain control (pin AGC) Gain control range for microphone and receiving amplifiers with respect to GVTRX ILINE = 85mA ILINE=15mA Highest line current for maximum gain ISTART Lowest line current for minimum gain ISTOP DTMF amplifier (pin DTMF) VDTMF = 20mV (RMS) Voltage gain from DTMF to LN GVDTMF 24.1 MUTE = LOW Gain variation with frequency referred to 1kHz Gain variation with temperature referred to25°C Voltage gain from DTMF to QR (confidence tone) Mute function (pin MUTE) 34 dB ±0.2 dB ±0.3 dB 14 0.25 dB V 0.35 -87 dBVp 5.9 dB 23 56 mA mA 25.3 26.5 dB ±0.2 dB GVDTMF(T) Ta = -25 ~ +75 °C ±0.4 dB -15 dB GVCT VIL HIGH level input voltage VIH VDTMF = 20mV (RMS) RL = 150 Ω IMUTE GVTRXM VEE +0.3 VCC +0.4 VEE -0.4 VEE +1.5 MUTE = LOW UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 33 GVDTMF(F) f = 300~3400Hz LOW level input voltage Input current Gain reduction for microphone and receiving amplifiers TYP MAX UNIT V V 1.5 μA 80 dB 4 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT APPLICATION INFORMATION CIRCUIT Typical application of the UTC TEA1110A in sets with Pulse Dialling or Flash facilities RCC Rprotect 10Ω BZX79C10 4× BAS11 a/b Telephone line VDR 95V + 619 Rast1 130KΩ CIR LN IR QR C GAR Rast2 100pF 3.92kΩ Rast3 390Ω Zbal signal from dial and control circuits DTMF MUTE AGC VEE MIC SLPE REG RSLPE 20Ω supply for peripheral circuits UTC TEA1110A GAR 1 nF + Vcc MIC + CGARS CVCC 100μF +C Rpd4 REG 4.7μF BC558 Rpd5 470kΩ 470kΩ Rpd6 BSN254 b/a BF473 Rpd1 BC547 68kΩ PD input 470kΩ BC547 RLIMIT 3.9Ω UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw BZX79C10 Rpd2 470kΩ Rpd3 1MΩ 5 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT FUNCTIONAL DESCRIPTION Supply (pins LN, SLPE, VCC and REG) The UTC TEA1110A and its peripheral circuit derive the power supply from telephone line (see Fig.1). The IC generates a stabilized reference voltage (VREF) between pins LN and SLPE. The voltage at pin SLPE is proportional to the line current. VREF is temperature compensated and can be adjusted by means of an external resistor (RVA). VREF is set to 3.35 V, which can be increased by connecting RVA between pins REG and SLPE (see Fig.2) and be decreased by connecting RVA between pins REG and LN. The voltage at pin REG is used by the internal regulator to generate VREF and is decoupled by, which is connected to VEE. This CREG capacitor converted into an equivalent inductance (see Section “Set impedance”) realizes the set impedance conversion from its DC value (RSLPE) to its AC value (RCC in the audio-frequency range). In the following formula, the most appropriate value for RSLPE is 20 Ω. The changing of RSLPE will affect the DC characteristics; furthermore, it can influence the microphone and DTMF gains, the gain control characteristics, the side tone level and the maximum output swing on the line. The voltage at pin LN is: VLN = VREF +RSLPE×ISLPE ISLPE = IIINE-ICC-IP-I* Where: ILINE = line current ICC = current consumption of the IC IP = supply current for peripheral circuits I* = current consumed between LN and VEE. Rline RCC Rexch + - 619Ω LN 1 lline VCC 14 IP UTC TEA1110A I* Ish + - ISLPE + CVCC Peripheral 100μF circuits from pre amp Vd Vexch ICC + 3 REG + CREG 4.7μF 2 SLPE RSLPE 20Ω 11 VEE Fig 1. Supply configuration. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT FUNCTIONAL DESCRIPTION(Cont.) Fig.2 Reference voltage adjustment by RVA 6.0 5.0 4.0 (1) (2) 3.0 104 105 RVA (Ω) 106 107 (1) Influence of RVA on VREF (2) VREF without influence of RVA The internal circuitry of the UTC TEA1110A is supplied from pin VCC which can be used to supply peripheral circuits such as dialling or control circuits. This voltage supply is derived from the line voltage by means of a resistor (RCC) and it must be decoupled by a capacitor CVCC. The VCC voltage depends on the current consumed by the IC and the peripheral circuits as shown by the formula :( RCCint is the internal equivalent resistance of the voltage supply, and Irec is the current consumed by the output stage of the earpiece amplifier)) VCC= VCC0 - RCCint × (IP-IREC) V CC0= VLN-RCC × ICC (see also Figs 3 and 4). The DC line current flowing into the set is determined by the exchange supply voltage (Vexch), the feeding bridge resistance (Rexch), the DC resistance of the telephone line (Rline) and the reference voltage (VREF). The internal reference voltage (generating VREF) would be automatically adjusted to a lower value when the line currents drop below 7.5mA. Therefore, more sets can work in parallel with DC line voltages (excluding the polarity guard) down to 1.6V (absolute minimum voltage). At currents below 7.5mA, the circuit has limited sending and receiving levels. This is called the low voltage area. 2.5 2 Rccint Vcc 1.5 + Vcco Irec 1 Ip VEE (1) (2) 0.5 PERIPHERAL CIRCUIT (1) With RVA resistor. (2) Without RVA resistorl 0 0 1 2 Vcc (V) 3 4 Fig.3 Typical current IP available from VCC for peripheral circuits at ILINE=15mA. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw Fig.4 VCC supply voltage for peripherals 7 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT FUNCTIONAL DESCRIPTION(Cont.) Set impedance The dynamic impedance is mainly determined by the RCC resistor within the audio frequency range. The equivalent impedance of the circuit is shown in Fig.5. LN Rcc 619Ω Rp LEQ Vref SLPE REG + RSLPE VEE 20Ω CREG 4.7μF LEQ=CREG × RSLPE × Rp Rp=internal resistance Rp=15.5kΩ Vcc + Cvcc 100μF Fig.5 Equivalent impedance between LN and VEE Microphone amplifier (pins MIC+ and MIC-) The UTC TEA1110A has symmetrical microphone inputs. The input impedance between pin MIC+ and pin MICis 64kΩ (2 × 32kΩ). On this microphone amplifier, automatic gain control is used for line loss compensation. Receiving amplifier (pins IR, GAR and QR) The receiving amplifier has one input (IR) and one output (QR). The input impedance between pin IR and pin VEE is 20kΩ. Connecting an external resistor RGAR between pins GAR and QR can decrease the voltage gain within 14dB from pin IR to pin QR. The two external capacitors CGAR (connected between pins GAR and QR) and CGARS (connected between GAR and VEE) ensure stability, the CGAR capacitor provides a first-order low-pass filter. The cut-off frequency corresponds to the time constant CGAR × (RGARint // RGAR). And the RGARint is the internal resistor connected between pins GAR and QR which sets a 125 kW typ gain. The condition CGARS = 10 ×CGAR is required to ensure stability. The output voltage of the receiving amplifier is for continuous wave drive specially. The maximum output swing depends on the DC line voltage, the RCC resistor, the ICC current consumption of the circuit, the IP current consumption of the peripheral circuits and the load impedance. On this receiving amplifier automatic gain control is used for line loss compensation. Automatic gain control (pin AGC) The UTC TEA1110A performs automatic line loss compensation. The automatic gain control varies both the gain of the microphone amplifier and receiving amplifier in accordance with the DC line current within 5.9 dB (which corresponds approximately to a line length of 5 km for a 0.5 mm diameter twisted-pair copper cable with a DC resistance of 176Ω/km and an average attenuation of 1.2dB/km). The IC can be used with different configurations of feeding bridge (supply voltage and bridge resistance) by the means of connecting an external resistor RAGC between pins AGC and VEE. The line currents ISTART and ISTOP can be increased by this resistor (the ratio between ISTART and ISTOP is not affected by the resistor). When pin AGC is in the open-circuit condition, the AGC function is inactive. Mute function (pin MUTE MUTE) The mute function performs the switching between the speech mode and the dialling mode. When the MUTE is in a low level, the DTMF input is active and the microphone and receiving amplifiers inputs are inactive. When the MUTE is in a high level, the microphone and receiving amplifiers inputs are active while the DTMF input is inactive. The input includes a pull-up resistor. DTMF amplifier (pin DTMF) When the DTMF amplifier is inactive, dialling tones that can be heard in the earpiece at a low level may be sent on line. The UTC TEA1110A has an asymmetrical DTMF input. The input impedance between DTMF and VEE is 20kΩ. The automatic gain control has no effect on the DTMF amplifier. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 9 QW-R108-014.C TEA1110A LINEAR INTEGRATED CIRCUIT FUNCTIONAL DESCRIPTION(Cont.) SIDETONE SUPPRESSION The UTC TEA1110A anti-side tone network consisting of RCC//Zline, Rast1, Rast2, Rast3, RSLPE and Zbal (see Fig.6) suppresses the transmitted signal in the earpiece. Maximum compensation is obtained under the following conditions: RSLPE×Rast1=RCC× (Rast2+Rast3) K= (Rast 2 × (Rast3 + RSLPE )) (Rast1× RSLPE ) Zbal= k×ZIine The scale factor k is mainly for the compatibility with a standard capacitor from the E6 or E12 range for Zbal. Zline varies considerably with the line type and the line length in practice. Therefore, the Zbal value should be set to be an average line length which gives appropriate side tone suppression with short and long lines. The suppression also depends on the accuracy of the match between Zbaland the impedance of the average line. The receiving signal is to be attenuated 32dB by the anti-side tone network from the line before it enters the receiving amplifier, and the attenuation is almost constant over the whole audio frequency range. LN R t1 as cc R Zline IR VEE Im PE SL R as t3 R R as t2 Zir SLPE Zbal Fig.6 Equivalent circuit of UTC TEA1110A anti-sidetone bridge UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 9 QW-R108-014.C