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公开(公告)号：US08965010B2
公开(公告)日：2015-02-24
申请号：US11175784
申请日：2005-07-05
CPC分类号： H03F1/305 , H03F3/3022 , H03F3/72 , H03F2203/7227 , H03F2203/7231
摘要： An amplifier (50) for voice or audio signals, and particularly for headset applications, uses a low gm amplifier (54) for initially charging an output node (OUT) at the beginning of a power-on phase. After charging the output node, a main amplifier (56) is enabled to amplify the voice or audio signal. At power-down, a sample-and-hold circuit (58) drives an output transistor to discharge an AC coupling capacitor (20). Thus, spikes at the output node are eliminated and an external filtering capacitor is not needed.
摘要翻译： 用于语音或音频信号的放大器（50），特别是用于耳机应用的放大器（50）使用低gm放大器（54）来在开机阶段开始时对输出节点（OUT）充电。 在对输出节点充电之后，使主放大器（56）能够放大声音或音频信号。 在断电时，采样和保持电路（58）驱动输出晶体管以对AC耦合电容器（20）进行放电。 因此，消除了输出节点处的峰值，并且不需要外部滤波电容器。
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公开(公告)号：US08472644B2
公开(公告)日：2013-06-25
申请号：US12792717
申请日：2010-06-02
申请人： Yi-Shang Chen , Chun-Hao Hsu
发明人： Yi-Shang Chen , Chun-Hao Hsu
IPC分类号： H03F21/00
CPC分类号： H03F3/2173 , H03F1/0205
摘要： A high efficiency audio amplifier is disclosed. The high efficiency audio amplifier includes an input end for receiving an input audio signal, an output end for outputting an output audio signal, a signal generator coupled to the input end for determining a frequency of an oscillating signal according to the distribution of the input audio signal and a reference voltage, and generating the oscillating signal accordingly, a waveform transformer coupled to the input end and the signal generator for comparing the input audio signal with the oscillating signal to generate a pulse width modulation (PWM) signal, a pre-drive circuit for generating a pre-drive signal according to the PWM signal, an output stage coupled to the pre-drive circuit for generating an output signal, and a filter coupled to the output stage for filtering the output signal to generate the output audio signal to the output end.
摘要翻译： 公开了一种高效率音频放大器。 高效率音频放大器包括用于接收输入音频信号的输入端，用于输出输出音频信号的输出端，耦合到输入端的信号发生器，用于根据输入音频的分布确定振荡信号的频率 信号和参考电压，并且相应地产生振荡信号，耦合到输入端的波形变换器和信号发生器，用于将输入音频信号与振荡信号进行比较以产生脉宽调制（PWM）信号，预驱动 用于根据PWM信号产生预驱动信号的电路，耦合到预驱动电路以产生输出信号的输出级，以及耦合到输出级的滤波器，用于对输出信号进行滤波以产生输出音频信号 输出端。
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公开(公告)号：US08457330B2
公开(公告)日：2013-06-04
申请号：US12211663
申请日：2008-09-16
申请人： John W. Curran , Edward V. Applegate , Joseph Kosich , Richard H. Fetterly , Anthony W. Russo, II , Brian E. Bizjak
发明人： John W. Curran , Edward V. Applegate , Joseph Kosich , Richard H. Fetterly , Anthony W. Russo, II , Brian E. Bizjak
IPC分类号： H03F21/00
CPC分类号： G08B7/066 , G08B3/10 , H04R27/00 , H04R29/007
摘要： The present invention is an apparatus and a concomitant method for boosting the audio signal generated by at least one notification appliance in a supervised emergency voice evacuation system.
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公开(公告)号：US08054129B2
公开(公告)日：2011-11-08
申请号：US12317613
申请日：2008-12-23
申请人： Toshio Maejima
发明人： Toshio Maejima
IPC分类号： H03F21/00
CPC分类号： H03F3/217 , H03F2200/66
摘要： A class D amplifier includes: an amplifier that generates a digital signal for driving a load based on an input signal; an attenuator that attenuates the input signal according to an attenuation command signal; and a clip prevention controller that outputs the attenuation command signal to intermittently attenuate the input signal when the digital signal is brought into a clip state or a near-clip state.
摘要翻译： D类放大器包括：放大器，其基于输入信号产生用于驱动负载的数字信号; 衰减器，其根据衰减命令信号衰减输入信号; 以及剪辑防止控制器，当数字信号进入剪辑状态或接近剪辑状态时，输出衰减命令信号来间断地衰减输入信号。
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公开(公告)号：US07969242B2
公开(公告)日：2011-06-28
申请号：US12324020
申请日：2008-11-26
IPC分类号： H03F21/00
CPC分类号： H03F3/2173
摘要： An apparatus and method for communications are disclosed. The apparatus may include an a quantizer having three levels, and a switching power amplifier configured to drive a load having first and second terminals, wherein the switching power amplifier is further configured to switch the first and second terminals between first and second power rails only if the output from the quantizer is at one of the three levels.
摘要翻译： 公开了一种用于通信的装置和方法。 该装置可以包括具有三个电平的量化器和被配置为驱动具有第一和第二端子的负载的开关功率放大器，其中开关功率放大器还被配置为仅在第一和第二电力轨之间切换第一和第二端子 量化器的输出处于三个级别之一。
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126.发明授权Over-current sensing during narrow gate drive operation of class D output stages 有权D类输出级窄栅极驱动运行时的过电流检测公开(公告)号：US07705673B2
公开(公告)日：2010-04-27
申请号：US11970289
申请日：2008-01-07
申请人： James Teng , Qiong M. Li , Cetin Kaya
发明人： James Teng , Qiong M. Li , Cetin Kaya
IPC分类号： H03F21/00
CPC分类号： H03F3/2173 , H03F1/523 , H03F2200/03 , H03F2200/351
摘要： Two transistors of a class D output stage are driven by complementary, variable duty cycle signals PWM+ and PWM−. When the pulse width of the PWM+ signal becomes too narrow for reliable operation of prior art over-current protection circuits sensing the drain to source voltage of FET1 driven by PWM+, a Narrow Pulse Detector generates a signal indicative of this narrow pulse condition. A Negative Current Sense circuit measures the drain to source voltage across FET2 during the much longer conduction time of FET2 driven by PWM−. Because of the energy stored in the series inductor coupled to the output of the class D stage, a negative current flows through this FET2 during its conduction time. The resulting drain to source voltage of FET2 is measured and compared to a threshold. If the voltage indicative of current is over the threshold, and the Narrow Pulse Detector output indicates a narrow pulse condition, then an inhibit signal is generated which reduces current. A second Negative Current Sense circuit is utilized to similarly detect over-current conditions when the pulse width of PWM− becomes too narrow for reliable operation of prior art over-current protection circuits, thus protecting both FETs in the class D output stage from excessive current.
摘要翻译： D类输出级的两个晶体管由互补的可变占空比信号PWM +和PWM-驱动。 当PWM +信号的脉冲宽度变得太窄，以便于感测由PWM +驱动的FET1的漏极 - 源极电压的现有技术的过电流保护电路的可靠操作时，窄脉冲检测器产生指示该窄脉冲条件的信号。 在由PWM驱动的FET2的更长的导通时间内，负电流检测电路测量FET2两端的漏源电压。 由于存储在串联电感器中的能量耦合到D级的输出端，所以在其导通时间期间，负电流流过该FET2。 测量FET2的所得到的源极到源极电压并将其与阈值进行比较。 如果指示电流的电压超过阈值，并且窄脉冲检测器输出指示窄脉冲条件，则产生减少电流的禁止信号。 使用第二负电流检测电路来类似地检测当PWM的脉冲宽度变得太窄以致于现有技术的过电流保护电路的可靠操作时的过电流状况，从而保护D类输出级中的两个FET免受过大的电流 。
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公开(公告)号：US07668321B2
公开(公告)日：2010-02-23
申请号：US10672534
申请日：2003-09-26
申请人： Greg A. Hupp
发明人： Greg A. Hupp
IPC分类号： H03F21/00
CPC分类号： H03F1/52 , G06F3/162 , H03G3/001 , H03G3/3089
摘要： A power foldback circuit to automatically control the power of an audio amplifier by using the volume inputs to a pre-amp source which drives the audio amplifier. In an embodiment, a Universal Serial Bus (USB) on a personal computer is used to drive the audio speakers. In this circuit an audio digital to analog converter (DAC) with a USB interface receives a digitally encoded audio signal from a personal computer (PC). The USB DAC outputs an analog audio signal to a audio amplifier circuit. A supervisory circuit monitors the power used by the audio amplifier and through a volume control circuit lowers the volume control into the USB DAC to prevent the entire circuit from drawing more than the allowed power supplied by the USB connection to the PC.
摘要翻译： 功率折返电路，通过使用驱动音频放大器的前置放大器源的音量输入来自动控制音频放大器的电源。 在一个实施例中，个人计算机上的通用串行总线（USB）用于驱动音频扬声器。 在该电路中，具有USB接口的音频数模转换器（DAC）从个人计算机（PC）接收数字编码的音频信号。 USB DAC将模拟音频信号输出到音频放大器电路。 监控电路监视音频放大器使用的功率，并通过音量控制电路将音量控制降低到USB DAC，以防止整个电路吸收超过由USB连接提供给PC的允许电力。
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公开(公告)号：US20090140900A1
公开(公告)日：2009-06-04
申请号：US12169520
申请日：2008-07-08
摘要： Disclosed are a sensor interface device and an amplifier used in a sensor system. The sensor interface device in one implementation has a first chopper configured to shift input signals of the sensor system from a baseband frequency to a first frequency, an instrumentation amplifier configured to amplify the shifted signals, a bandpass Delta-Sigma modulator configured to digitize the amplified signals, and a second chopper configured to shift the digitized signals from the a first frequency back to the baseband frequency. The instrumentation amplifier removes the DC offset generated from the first chopper and therefore all sources of DC offset are eliminated in this interface device without bandwidth limitation.
摘要翻译： 公开了一种用于传感器系统的传感器接口装置和放大器。 一个实施例中的传感器接口装置具有第一斩波器，其被配置为将传感器系统的输入信号从基带频率移位到第一频率，被配置为放大移位信号的仪表放大器，被配置为将放大的 信号，以及第二斩波器，被配置为将数字化信号从第一频率返回到基带频率。 仪表放大器消除了从第一个斩波器产生的直流偏移，因此在该接口器件中不会出现带宽限制的所有直流偏移源。
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公开(公告)号：US20090063720A1
公开(公告)日：2009-03-05
申请号：US12202361
申请日：2008-09-01
摘要： Systems and methods for controlling the capabilities of an High Definition Audio (HDA) system, wherein the system determines whether an optional component such as a plug-in card is connected to the system and then configures itself in a baseline configuration if the optional component is not connected or configures itself in a different, alternative configuration if the optional component is connected. In one embodiment, a codec of the system includes a programmable processor configured to read configuration authorization information and also read configuration information from the optional component if it is connected to the system. The processor also controls the configuration of the HDA system and the operation of the codec based on the authorization and configuration information. The system can thereby provide different features and functionality using the same hardware.
摘要翻译： 用于控制高清晰度音频（HDA）系统的能力的系统和方法，其中系统确定诸如插件卡的可选组件是否连接到系统，然后如果可选组件是 如果可选组件连接，则不连接或将其自身配置为不同的替代配置。 在一个实施例中，系统的编解码器包括可编程处理器，其被配置为读取配置授权信息，并且如果连接到系统则从可选组件读取配置信息。 处理器还根据授权和配置信息控制HDA系统的配置和编解码器的操作。 因此，该系统可以使用相同的硬件来提供不同的特征和功能。
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公开(公告)号：US07482870B2
公开(公告)日：2009-01-27
申请号：US11541999
申请日：2006-09-28
申请人： Toshio Maejima , Masayuki Iwamatsu
发明人： Toshio Maejima , Masayuki Iwamatsu
IPC分类号： H03F21/00
CPC分类号： H03F3/217 , H03F2200/66
摘要： A class D amplifier includes: an amplifier that generates a digital signal for driving a load based on an input signal; an attenuator that attenuates the input signal according to an attenuation command signal; and a clip prevention controller that outputs the attenuation command signal to intermittently attenuate the input signal when the digital signal is brought into a clip state or a near-clip state.
摘要翻译： D类放大器包括：放大器，其基于输入信号产生用于驱动负载的数字信号; 衰减器，其根据衰减命令信号衰减输入信号; 以及剪辑防止控制器，当数字信号进入剪辑状态或接近剪辑状态时，输出衰减命令信号来间断地衰减输入信号。
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