Deglitching circuit and method in class-D amplifier

    公开(公告)号:US10965263B2

    公开(公告)日:2021-03-30

    申请号:US16354760

    申请日:2019-03-15

    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.

    ADVANCED CURRENT LIMIT FUNCTION FOR AUDIO AMPLIFIER
    13.
    发明申请
    ADVANCED CURRENT LIMIT FUNCTION FOR AUDIO AMPLIFIER 有权
    用于音频放大器的高级电流限制功能

    公开(公告)号:US20160065148A1

    公开(公告)日:2016-03-03

    申请号:US14487313

    申请日:2014-09-16

    Abstract: A class-D audio amplifier incorporates an overcurrent protection scheme implementing two overcurrent thresholds to avoid a dynamic impedance drop. When output current reaches the first threshold as a result of an impedance drop across the speaker, the overcurrent protection circuitry limits the output current to the value of the first threshold, but does not shut down the circuit. The second threshold is used to detect an overcurrent condition to shut down the circuit. Current limiting logic of a first channel monitors the overcurrent condition of a second channel and controls the first channel output in response thereto. This permits the second channel output current to reach the second threshold if the circuit is experiencing a short-circuit condition. This scheme also allows the output current to drop below the first threshold if the overcurrent condition of the second channel is caused by an impedance drop across the output speaker.

    Abstract translation: D类音频放大器包含实现两个过流阈值的过流保护方案,以避免动态阻抗下降。 当输出电流由于扬声器上的阻抗降低而达到第一阈值时,过电流保护电路将输出电流限制在第一阈值的值,但不关闭电路。 第二个阈值用于检测过电流状态以关闭电路。 第一通道的电流限制逻辑监视第二通道的过电流状况并响应于此控制第一通道输出。 这允许第二通道输出电流达到第二阈值,如果电路正在经历短路状态。 如果第二通道的过电流状态是由输出扬声器上的阻抗下降引起的,则该方案还允许输出电流降至低于第一阈值。

    METHODS AND CIRCUITS TO REDUCE POP NOISE IN AN AUDIO DEVICE
    14.
    发明申请
    METHODS AND CIRCUITS TO REDUCE POP NOISE IN AN AUDIO DEVICE 有权
    减少音频设备中的POP噪声的方法和电路

    公开(公告)号:US20150071464A1

    公开(公告)日:2015-03-12

    申请号:US14478531

    申请日:2014-09-05

    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.

    Abstract translation: D类放大器接收和放大差分模拟信号,然后差分模拟信号被差分地积分。 两个脉冲宽度调制器产生对应于差分集成模拟信号的脉冲信号,两个功率单元产生输出脉冲信号。 功率单元的输出通过电阻反馈网络耦合到积分器的输入端。 模拟输出单元将脉冲信号转换为输出模拟信号。 差分积分电路实现静音/非静音之间的软转换。 静音时,积分器输出是固定的。 在软转换期间,PWM输出从固定的50%占空比缓慢变化到最终值,以确保由于模式更改导致输出中没有弹出噪声。

    DEGLITCHING CIRCUIT AND METHOD IN A CLASS-D AMPLIFIER

    公开(公告)号:US20210203293A1

    公开(公告)日:2021-07-01

    申请号:US17200490

    申请日:2021-03-12

    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.

    High efficiency class D amplifier with reduced generation of EMI

    公开(公告)号:US09866187B2

    公开(公告)日:2018-01-09

    申请号:US14715879

    申请日:2015-05-19

    Abstract: A class-D amplifier includes a signal processing block. The signal processing block generates a first processed signal representing a difference between a first differential signal and a second differential signal, when a duty cycle of the first differential signal is greater than that of the second differential signal. The signal processing block generates the first processed signal representing a reference DC level, when the duty cycle of the first differential signal is less than that of the second differential signal. A second processed signal representing a difference between the second differential signal and the first differential signal is generated when the duty cycle of the second differential signal is greater than that of the first differential signal, and the second processed signal representing the reference DC level is generated when the duty cycle of the second differential signal is less than that of the first differential signal.

    Methods and circuits to reduce pop noise in an audio device
    17.
    发明授权
    Methods and circuits to reduce pop noise in an audio device 有权
    减少音频设备弹奏噪音的方法和电路

    公开(公告)号:US09577579B2

    公开(公告)日:2017-02-21

    申请号:US15057552

    申请日:2016-03-01

    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.

    Abstract translation: D类放大器接收并放大差分模拟信号,然后差分模拟信号被差分地积分。 两个脉冲宽度调制器产生对应于差分集成模拟信号的脉冲信号,两个功率单元产生输出脉冲信号。 功率单元的输出通过电阻反馈网络耦合到积分器的输入端。 模拟输出单元将脉冲信号转换为输出模拟信号。 差分积分电路实现静音/非静音之间的软转换。 静音时,积分器输出是固定的。 在软转换期间,PWM输出从固定的50%占空比缓慢变化到最终值,以确保由于模式更改导致输出中没有弹出噪声。

    Advanced current limit function for audio amplifier
    20.
    发明授权
    Advanced current limit function for audio amplifier 有权
    音频放大器的高级限流功能

    公开(公告)号:US09276530B1

    公开(公告)日:2016-03-01

    申请号:US14487313

    申请日:2014-09-16

    Abstract: A class-D audio amplifier incorporates an overcurrent protection scheme implementing two overcurrent thresholds to avoid a dynamic impedance drop. When output current reaches the first threshold as a result of an impedance drop across the speaker, the overcurrent protection circuitry limits the output current to the value of the first threshold, but does not shut down the circuit. The second threshold is used to detect an overcurrent condition to shut down the circuit. Current limiting logic of a first channel monitors the overcurrent condition of a second channel and controls the first channel output in response thereto. This permits the second channel output current to reach the second threshold if the circuit is experiencing a short-circuit condition. This scheme also allows the output current to drop below the first threshold if the overcurrent condition of the second channel is caused by an impedance drop across the output speaker.

    Abstract translation: D类音频放大器包含实现两个过流阈值的过流保护方案,以避免动态阻抗下降。 当输出电流由于扬声器上的阻抗降低而达到第一阈值时,过电流保护电路将输出电流限制在第一阈值的值,但不关闭电路。 第二个阈值用于检测过电流状态以关闭电路。 第一通道的电流限制逻辑监视第二通道的过电流状况并响应于此控制第一通道输出。 这允许第二通道输出电流达到第二阈值,如果电路正在经历短路状态。 如果第二通道的过电流状态是由输出扬声器上的阻抗下降引起的,则该方案还允许输出电流降至低于第一阈值。

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