Modulated gain audio control and zipper noise suppression techniques using modulated gain
    1.
    发明授权
    Modulated gain audio control and zipper noise suppression techniques using modulated gain 有权
    使用调制增益的调制增益音频控制和拉链噪声抑制技术

    公开(公告)号:US08249275B1

    公开(公告)日:2012-08-21

    申请号:US12493054

    申请日:2009-06-26

    IPC分类号: H04B15/00

    摘要: A modulated gain audio control and zipper noise suppression techniques provide reduction in audible artifacts caused by discrete-valued gain changes. The gain of a signal is controlled by modulating between multiple gain values for corresponding time durations, so that a resulting average gain is controlled according to the average of the multiple gain values as weighted by their corresponding time durations. The modulation frequency is above the bandwidth of the signal. Transitions between gain levels are performed by changing the relative proportion of the durations to slowly change the gain according to a transition profile, which may be linear or non-linear. The modulation employed may be pulse-width modulation, or another modulation pattern such as a delta-sigma modulation pattern.

    摘要翻译: 调制增益音频控制和拉链噪声抑制技术提供了由离散值增益变化引起的声音伪像的减少。 通过在相应的持续时间的多个增益值之间进行调制来控制信号的增益,从而根据由相应的持续时间加权的多个增益值的平均值来控制所得到的平均增益。 调制频率高于信号的带宽。 通过改变持续时间的相对比例来实现增益水平之间的转换,以根据可以是线性或非线性的转移轮廓来缓慢地改变增益。 所采用的调制可以是脉冲宽度调制,或者诸如Δ-Σ调制模式的另一种调制模式。

    Discrete-time delta-sigma modulator with improved anti-aliasing at lower quantization rates
    2.
    发明授权
    Discrete-time delta-sigma modulator with improved anti-aliasing at lower quantization rates 有权
    离散时间Δ-Σ调制器,在较低量化速率下具有改进的抗锯齿

    公开(公告)号:US08130127B1

    公开(公告)日:2012-03-06

    申请号:US12827522

    申请日:2010-06-30

    IPC分类号: H03M3/00

    CPC分类号: H03M3/322 H03M3/452

    摘要: A discrete time delta-sigma modulator circuit, which may be used to implement an analog-to-digital converter (ADC) provides improved anti-aliasing performance when lower quantization rates are selected, by maintaining the clocking rate of a first stage in the delta-sigma modulator loop filter at a rate higher than would ordinarily be selected for a lower quantization rate. To accomplish the anti-aliasing improvement, the ratio between the quantization rate and the clocking rate of the first integrator is reduced at the lower quantization rate, resulting in a first true alias image at a multiple of the quantization rate, permitting anti-aliasing filters to more effectively attenuate the alias image, and attenuating the images spaced at the quantization rate via the averaging operation of the first integrator.

    摘要翻译: 可用于实现模数转换器(ADC)的离散时间Δ-Σ调制器电路通过将第一级的时钟速率保持在三角形(delta)中来提供较低量化速率时提供的改进的抗混叠性能 Σ调制器环路滤波器的速率高于通常为较低量化速率选择的速率。 为了实现抗锯齿改进,第一积分器的量化速率与时钟速率之间的比例以较低的量化速率降低,从而产生了以量化速率倍数的第一真实混叠图像,从而允许抗混叠滤波器 以更有效地衰减别名图像,并且通过第一积分器的平均化操作来衰减以量化速率间隔的图像。

    Audio amplifier offset reduction using digital input/output comparisons
    3.
    发明授权
    Audio amplifier offset reduction using digital input/output comparisons 有权
    使用数字输入/输出比较的音频放大器偏移量减少

    公开(公告)号:US08525710B1

    公开(公告)日:2013-09-03

    申请号:US12750973

    申请日:2010-03-31

    IPC分类号: H03M1/06 H03M1/66 H03F99/00

    摘要: An offset correction circuit removes DC offset from an analog audio output signal by comparing transitions of digital audio values to which the analog output signal is related to the output of a monitor that monitors the analog output signal. The monitor may be a zero-crossing detector and the transitions of the digital signal that are compared may be transitions of the most-significant bit (MSB) of the digital audio values. A filtering algorithm or filter circuit may be used to average a result of the comparison of the transitions, so that the offset is slowly and accurately removed. A chopped or autozero comparator may be used to further reduce error in the offset determination.

    摘要翻译: 偏移校正电路通过比较模拟输出信号与监视模拟输出信号的监视器的输出相关的数字音频值的转换,从模拟音频输出信号中去除DC偏移。 监视器可以是过零检测器,并且被比较的数字信号的转变可以是数字音频值的最高有效位(MSB)的转换。 可以使用滤波算法或滤波器电路来平均转换的比较的结果,使得偏移被缓慢且精确地去除。 可以使用斩波或自动调零比较器来进一步减少偏移确定中的误差。

    Modulated audio amplifier output enable control
    4.
    发明授权
    Modulated audio amplifier output enable control 有权
    调制音频放大器输出使能控制

    公开(公告)号:US07990212B1

    公开(公告)日:2011-08-02

    申请号:US12641524

    申请日:2009-12-18

    IPC分类号: H03F1/14

    CPC分类号: H03F1/305 H03G3/348

    摘要: A modulated amplifier output enable control eliminates audible pops when enabling and disabling an audio amplifier output stage. The output of the audio amplifier is transitioned between an enabled state and a disabled state using a modulated control signal that enables and disables the output of the audio amplifier. Durations of the enabled state vs. the disabled state of the amplifier are adjusted to cause a transition between a fully disabled state and a fully enabled state of the audio amplifier so that the transition between the disabled state and the enabled state of the amplifier output is inaudible.

    摘要翻译: 调制放大器输出使能控制可在启用和禁用音频放大器输出级时消除可听见的声音。 音频放大器的输出使用调制控制信号在使能状态和禁用状态之间转换,该调制控制信号使能和禁止音频放大器的输出。 调整使能状态与放大器的禁用状态的持续时间,以使得音频放大器的完全禁止状态和完全启用状态之间的转变,使得禁用状态和放大器输出的使能状态之间的转换是 听不见