ts34118 Taiwan Semiconductor Company, Ltd. (TSC), ts34118 Datasheet
ts34118
Related parts for ts34118
ts34118 Summary of contents
Page 1
... Chip Disable pin permits powering down the entire circuit to conserve power on long loops where loop current minimum. The TS34118 may be operated from a power supply can be powered from the telephone line, requiring typically 5.0mA. The TS34118 can be interfaced directly to Tip and Ring (through a coupling transformer) for stand-alone ...
Page 2
... RXI input resistance (RXI<350mVrms) Transmit attenuator gain (f=1.0KHz) Tx model , TXI=150mVrms Idle model, TXI=150mVrms Range ( model) TXO DC voltage (Tx model) ûTXO DC voltage ( model) TXO High voltage (Iout=-1.0mA TXI=V TXO Low voltage (Iout=+1.0mA TXI=V Output measured with respect TS34118 Min. Typ. 3 0.3xV -- B ...
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... Source current at RLO1, RLO2, TLO1, TLO2 Sink current at RLO1, RLO2, TLO1, TLO2 CPR, CPT output resistance (Iout=1.5mA) CPR, CPT leakage current Filter (T =+25:) A Voltage offset 220K from sink current FI bias current TS34118 =+25, Vcc=5.0V, CD” 0.8V, unless noted) A Symbol R TXI ...
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... 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+) TS34118 =+25, Vcc=5.0V, CD” 0.8V, unless noted) A Symbol THD R THD T Typical Value @25: 5 ...
Page 5
... Input to the receive level detector on the line side. 27 CPR this pin sets the time constant for the receive background monitor. 28 GND Ground pin for the entire IC. TS34118 Description B. , the receive attenuator is at maximum gain when in the B , the receive gain is down 35dB. Does not affect the transmit B ...
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... Typical Application Circuit Figure 1. Hybrid Amplifier Distortion Test TS34118 Figure 2. TS34118 Block Diagram 6-20 2004/09 rev. B ...
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... The TS341118 provides the necessary level detectors, attenuators, and switching control for a properly operating speakerphone. The detection sensitivity and timing are externally controllable. Additionally, the TS34118 provides background nodule monitor’s which make the circuit insensitive to room and line noise, hybrid amplifier, and other associated functions, please refer to the Block Diagram (Figure 2) when reading the following sections ...
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... Attenuator Control Block. Likewise, outputs RLO2 and TLO2 feed a second comparator which also goes to the Attenuator Control Block. The touch table for the effects of the level detectors on the Control Block is given in the section describing the Control Block. TS34118 , the circuit is in the receive mode (receive attenuator ...
Page 9
... The purpose of this circuit is to prevent the dial tone (which would be considered as continuous noise) from fading away as the circuit would have the tendency to switch to the idle mode. By disabling the receive idle mode, the dial tone remains at the normally expected full level. TS34118 . As VLC is reduced below V , the gain of the receive attenuator is reduced (see ...
Page 10
... In general, the fast idle mode will occur infrequently. TS34118 Output C4 ...
Page 11
... Figure 7). The mute input has a threshold of §1.5 volts, and the voltage at this pin must be kept within the range of ground and Vcc (see Figure 17). If the mute function is not used, the pin should be grounded. TS34118 11-20 , while the inverting input and B 2004/09 rev ...
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... Filter The operation of the filter circuit is determined by the external components. The circuit within the TS34118, from pins buffer with a high input impedance (>1.0M:), and a low output impedance (<50:). The configuration of the external components determines whether the circuit is a high-pass filter (as shown in Figure 2), a low-pass filter band-pass filter ...
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... Vcc . not used, the pin should be grounded. Switching Time The switching time of the TS34118 circuit is dominated by the components at C secondarily by the capacitors at the level detector outputs (RLO1, RLO2, TLO1, TLO2). The time to switch to receive or to transmit from idle is determined by the capacitor at C current sources (refer to Figure 6). The switching time is: û ...
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... It is desirable to have the majority f that gain in the microphone amplifier for three reasons: 1) The low level signals from the microphone should be amplifier as soon as possible to minimize signal/noise problems. TS34118 = 120K , the time constant is §600ms, giving a switching time of § 1.8 seconds tip and Ring, is determined by the output characteristics of the ...
Page 15
... Where V is the microphone voltage. Since the switching threshold occurs when I1=I3, combining the above two M equations yields: > × TS34118 (Equation 1) +G <0 (Equation =-40dB, the required acoustic coupling can º » (Equation 4) ¼ ...
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... idle, where the gain of the two attenuators is –20dB (0.1V/V), Equations 6 and 10 yield the same result: V =0.024V (Equation 12 Equations 7, 11 and 12 define the thresholds for switching, and are represented in the following graph: TS34118 º HA (Equation 8) » ¼ 2 (Equation ...
Page 17
... RC’s impedance should be kept within the range of 2.0K-15K in the voice band (due to the typical signal levels present) to obtain the best performance from the level detectors. The specific R and C at each location will determine the frequency response of that level detector. TS34118 Figure 11. Switching Threshold line represents the transmit to receive ...
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... Transmit / Receive Detection Priority Although the TS34118 was designed to have an idle mode such that the attenuators are halfway between their full on and full off positions, the idle mode can be biased towards the transmit or the receive side. With this done, gaining control of the circuit from idle will be easier for that side towards which it is biased since that path will have less attenuation at idle ...
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... RFI may enter the circuit through Tip and Ring, through the microphone wiring to the microphone amplifier, or through any of the PC board trances. The most sensitive pins on the TS34118 are the inputs to the level detectors (RLI1, RLI2, TLI1, TLI2) since, when there is no speech present, the inputs are high impedance and these op amps are in a near open loop condition ...
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... SOP-28 Mechanical Drawing DIP-28 Mechanical Drawing TS34118 SOP-28 DIMENSION MILLIMETERS DIM MIN A 17.70 B 7.41 C 10.15 D 2.37 E 1.27BSC F 0.40REF G 0.10 H 0.60 I 0.25BSC J 0.254TYP K 0.5 DIP-28 DIMENSION MILLIMETERS DIM MIN A 36.95 B 13.76 C 3.81 D 0.38 E 2.54TYP F 0.45TYP G 1.27TYP H 0.119 14.986 K 0.254NOM L 16.00 20-20 INCHES MAX MIN MAX 18.00 0.697 0.709 7.59 0.292 0.299 10 ...