U4082B ATMEL Corporation, U4082B Datasheet
U4082B
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U4082B Summary of contents
Page 1
... Low-Voltage Voice-Switched IC for Hands-Free Operation Description The low-voltage voice-switched speakerphone circuit, U4082B, incorporates the wide range of functions listed below. Versatility of the device is further enhanced by giving access to internal circuit points. The block diagram (figure 1) shows amplifiers, level detectors, transmit and receive attenuators operating in complementary func- ...
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... U4082B 2 (22) Figure 2. Block diagram with external circuit Rev. A2, 12-Feb-01 ...
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... RLO1 26 RLI1 . 27 CPR GND B U4082B Function Transmit attenuator input. Maximum sig- nal level is 350 mVrms. Input impedance is approximately 10 kW Microphone amplifier output. Gain is set by external resistors. Microphone amplifier input. Bias voltage is approximately Mute input. A logic low (< 0.8 V) sets normal operation. A logic high (> mutes the microphone amplifier without affecting the rest of the circuit ...
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... The U4082B provides the necessary level detectors, attenuators, and switching control for a properly operating speakerphone. The detection sensitivity and timing are externally controllable. Additionally, the ...
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... This output is sensed by the attenuator control block. Background noise monitor 4 mA – – (18) – (C1) Comparator 24 (19 Figure 4. Level detectors U4082B V S (CPT) CPR (16) 100 kW 27 – (C3) To attenuator control block 93 7741 e 5 (22) ...
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... U4082B The 36-mV offset at the comparator’s input keeps the comparator from changing state unless the speech level exceeds the background noise by approximately 4.0 dB. The time constant of the external RC (approximately 4.7 seconds) determines the response time to background noise variations. Volume Control The volume control input at VCI (Pin 13) is sensed as a voltage w ...
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... A diagram of the C operates as follows 7744 e Figure 6. C U4082B circuitry is shown in figure 6, and T – To attenuators + 4 Attenuator C1 ... C4 control Volume control Dial tone detector AGC Attenuator control block circuit T 7 (22) ...
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... The connections to the coupling transformer are shown in figure 1. Balancing network is necessary to match the line – with an impedance. S Filter The operation of the filter circuit is determined by the external components. The circuit within the U4082B from pins buffer with a high input impedance V (> 1 MW) and a low output impedance (< 50 W). The ...
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... The input impedance typically 90 kW, has a threshold of approximately 1.5 V, and the voltage at this pin must be kept within the range of ground and V (see figure 18 not used, the pin should S be grounded. U4082B 0. ...
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... U4082B Absolute Maximum Ratings Reference point Pin 28 unless otherwise specified. amb Parameters Supply voltage Voltages Storage temperature range Junction temperature Ambient temperature range Power dissipation amb Maximum thermal resistance Junction ambient Operation Recommendation Parameters Test Conditions / Pins Supply voltage CD input MUTE input ...
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... RECO DV RECO + 1 RECOH – RECOL +1 TOH V TOL –1 Idle U4082B Min. Typ. Max. Unit 5.5 8 600.0 800.0 50.0 90 0.0 0.8 1.3 V 1.8 2.1 2.4 W 400.0 54.0 dB +4.0 +6.0 +8.0 dB –0.5 0.0 +0.5 –25.0 –15.0 –22.0 –20.0 –17.0 dB 49.0 52.0 54 ...
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... U4082B Electrical Characteristics (continued 0.8 V, unless otherwise specified amb S Parameters Attenuator control C voltage Pin 14 – mode, V Idle mode T mode C source current R mode T C sink current T mode T C slow idle current T C fast idle internal T resistance VCI input current Dial tone detector threshold Microphone amplifier V < ...
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... Figure 10. Hybrid amplifier distortion test Typical Value @ 255C 5.0 mA 400 2 +6.0 dB –46.0 dB 10.0 kW 15.0 mV "60.0 mA 0.0 mV 1.0 4.0 mA 0.0 dB U4082B Min. Typ. Max. 0.8 1.0 1.2 –2.0 4.0 35 –0.2 –200.0 –90 0.0 150.0 260 400.0 –50.0 0.5 3.0 0.8 3.0 ...
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... U4082B 10 0 – attenuator – 20 – 30 – 40 – 50 – 320 – 160 0 V – V (mV 7767 e Figure 11. Attenuator gain versus VCT (Pin 14) 500 400 300 200 100 0 0 – 20 – 40 – (mA 7768 e Figure 12. Level detector DC transfer characteristics 300 0.1 mF 250 ...
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... S 2.0 1.5 1 7776 e Figure 20 CDv 0. 0.3 93 7778 e Figure 21. V U4082B 120 100 1000 3 0.5 1.0 1.5 2.0 2.5 –I (mA) (Load Current) B output characteristics B = 1000 500 mF 200 mF 100 mF ...
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... U4082B Design Guidelines Switching Time The switching time of the U4082B circuit is determined by C (Pin 14, refer to figure 5), and secondarily by the T capacitors at the level detector outputs (RLO1, RLO2, TLO1, TLO2). See figure 2. The time to switch from idle to receive or transmit mode is determined by the capacitor at C internal current sources ...
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... RECO; – the gain of the speaker amplifier, measured SA from RECO to the differential output of the U4083B (typically 22 V/V or 26.8 dB); – the acoustic coupling, measured from the AC speaker differential voltage to the microphone output voltage. U4082B MICO HTO–, HTO Hybrid amp ...
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... U4082B I) Transmit gain The transmit gain, from the microphone output (V Tip and Ring, is determined by the output characteristics of the microphone, and the desired transmit level. For example, a typical electret microphone will produce approximately 0.35 mVrms under normal speech conditions. To achieve 100 mVrms at Tip/Ring, an overall gain of 285 V/V is necessary ...
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... D The M T coupling (G found using the following equation Using the component values of figure 2 in equation 14 yields a maximum sidetone of 0 dB. Experience has shown, however, that a minimum of 6.0 dB loss is preferable. U4082B Figure 25. Switching thresholds the actual performance of the line helps define the maximum acoustic ...
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... Transmit/Receive Detection Priority Although the U4082B was designed to have idle mode such that the attenuators are halfway between their full on and full off positions, idle mode can be biased towards the transmit or the receive side ...
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... Package Information Package SO28 Dimensions in mm 18.05 17.80 0.4 1.27 16. Rev. A2, 12-Feb-01 U4082B 9.15 8.65 7.5 7.3 2.35 0.25 0.10 10.50 10.20 15 technical drawings according to DIN specifications 14 0.25 13033 21 (22) ...
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... U4082B Ozone Depleting Substances Policy Statement It is the policy of Atmel Germany 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 ...