Clipping state detecting circuit and clipping state detecting method
AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
InventorTakayuki Takida
Life of this patent
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Abstract
According to one embodiment, a clipping state detecting circuit includes: a zero-cross detection circuit that detects a zero-cross point of an input signal; an output circuit that converts the input signal into a PWM signal; a clip detection circuit that detects a state in which an output of the output circuit is clipped; and a control circuit that determines a state is a clipping state when a clip time of the output of the output circuit satisfies a condition of a threshold value set in advance with respect to a non-clip time.
Claims20
A clipping state detecting circuit comprising:
- a zero-cross detection circuit that detects a zero-cross point of an input signal and outputs a zero-cross signal;
- an output circuit that converts the input signal into a pulse width modulation (PWM) signal;
- a clip detection circuit that detects a state in which an output of the output circuit is clipped and outputs a clip detection signal;
- and
- a control circuit that determines that a state is a clipping state when a clip time in which the output of the output circuit is clipped satisfies a condition of a threshold value set in advance with respect to a non-clip time from a point in time at which the zero-cross signal is output to a point in time at which the clip detection signal is output.
A clipping state detecting method for detecting a clipping state of a pulse width modulation (PWM) output signal output from a PWM signal output circuit in response to an input signal, the clipping state detecting method comprising:
- receiving the input signal;
- detecting a zero-cross point of the input signal;
- converting the input signal into a PWM signal;
- detecting a state in which the PWM signal is clipped;
- counting a clip time in the state in which the PWM signal is clipped;
- counting a non-clip time from the zero-cross point to a point in time at which the clip detection signal is output;
- and
- determining that a state is a clipping state when the clip time satisfies a condition of a threshold value set in advance with respect to the non-clip time.
Dependencies are inferred from the claim text.