Simple circuit limits amplifie
to enable an audio amplifier to accommodate both loud and soft-spoken voices without clipping the loud waveforms, you can implement a nonlinear transfer function by adding a few components to a standard application circuit.
amplifying the human voice presents tough challenges. one of the toughest is providing enough amplification to make a soft-spoken person understood while allowing sufficient headroom for people who speak loudly. if the amplification is too high, a loud voice or noise causes clipping of the audio waveform, which makes the subsequent signal unintelligible and harsh to the ears.
one response to this dilemma is to limit the signal with a nonlinear transfer function (figure 1), implemented by adding a few components to a standard application circuit. when a positive or negative peak of the audio input exceeds the turn-on voltage for one of the back-to-back diodes (d1), the diode conducts and attenuates any further increase in the signal amplitude. resistors r1 and r2 add a series impedance that prevents excessive loading of the audio source.
figure 1. a small-signal diode network limits an amplifier's output voltage.
during normal operation, the incoming audio sees little attenuation by the diode network, and the high input impedance of u1 max9700a) prevents attenuation due to the higher source impedance. as input amplitudes increase the transfer function shifts, as shown in a plot of output amplitude vs. input amplitude (figure 2). as you can see, the output tracks the input for low-level signals, and above input levels of 0.5vrms the circuit gain decreases. gain compression is independent of the peak output voltage, as illustrated by the responses for various supply voltages.
figure 2. signal attenuation by the diode network in figure 1 prevents output clipping by causing a nonlinear transfer of the higher-amplitude inputs. note that 3.3v with clamp and 5v with clamp have the same response and are therefore superimposed. also, 2.5v and 3.3v show compression due to swing limits, even though no clamp is present.
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Simple circuit limits amplifie
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amplifying the human voice presents tough challenges. one of the toughest is providing enough amplification to make a soft-spoken person understood while allowing sufficient headroom for people who speak loudly. if the amplification is too high, a loud voice or noise causes clipping of the audio waveform, which makes the subsequent signal unintelligible and harsh to the ears.
one response to this dilemma is to limit the signal with a nonlinear transfer function (figure 1), implemented by adding a few components to a standard application circuit. when a positive or negative peak of the audio input exceeds the turn-on voltage for one of the back-to-back diodes (d1), the diode conducts and attenuates any further increase in the signal amplitude. resistors r1 and r2 add a series impedance that prevents excessive loading of the audio source.
figure 1. a small-signal diode network limits an amplifier's output voltage.
during normal operation, the incoming audio sees little attenuation by the diode network, and the high input impedance of u1 max9700a) prevents attenuation due to the higher source impedance. as input amplitudes increase the transfer function shifts, as shown in a plot of output amplitude vs. input amplitude (figure 2). as you can see, the output tracks the input for low-level signals, and above input levels of 0.5vrms the circuit gain decreases. gain compression is independent of the peak output voltage, as illustrated by the responses for various supply voltages.
figure 2. signal attenuation by the diode network in figure 1 prevents output clipping by causing a nonlinear transfer of the higher-amplitude inputs. note that 3.3v with clamp and 5v with clamp have the same response and are therefore superimposed. also, 2.5v and 3.3v show compression due to swing limits, even though no clamp is present.
江波龙的FORESEE车规级eMMC的优势到底是什么
挤下苹果，美国超威半导体成台积电7纳米最大客户
基于SCM701的电力数据采集终端设计
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Simple circuit limits amplifie
中国智能手机市场趋势报告
飞利浦OLED电视评测 高水准的音画质让人印象深刻
联发科将成为营收破百亿美元的芯片巨头
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大族数控获2020年度深圳市科学技术奖
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iPhone11上市两周热度高 占据美国消费iPhone销量20%
美国Acuity Brands与两家企业签署战略合作协议，制造UV消毒解决方案
下游头部电池企业产能需求大增，正在引发上游锂盐价格上涨
锐龙R1000系列新增两款新品 均为双核心四线程主打超低功耗
半导体设备进口是否受限制？中芯国际回应：不方便透露
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