System and method of shaping a power spectrum in PWM amplifiers
First Claim
Patent Images
1. A circuit comprising:
- an input terminal for receiving a pulse sequence having a particular spectral shape; and
a pulse edge control circuit to selectively apply a carrier suppression operation to at least one pulse-width modulated (PWM) signal in response to the pulse sequence to produce at least one adjusted PWM output signal;
wherein spectral energy of a carrier signal of the at least one adjusted PWM output signal at a carrier frequency of the carrier signal and harmonics of the carrier frequency is changed such that the at least one adjusted PWM output signal has a spectral shape defined by the particular spectral shape.
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Abstract
In a particular embodiment, a circuit device is disclosed that includes a data generator adapted to output a random pulse sequence having a particular spectral shape. The circuit device further includes a pulse edge control circuit to selectively apply a carrier suppression operation to at least one pulse-width modulated (PWM) signal in response to the random pulse sequence to produce at least one modulated PWM output signal. The spectral energy associated with a PWM carrier of the modulated PWM output signal at a carrier frequency and associated harmonics is changed such that the modulated PWM output signal has a spectral shape defined by the particular spectral shape.
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Citations
23 Claims
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1. A circuit comprising:
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an input terminal for receiving a pulse sequence having a particular spectral shape; and a pulse edge control circuit to selectively apply a carrier suppression operation to at least one pulse-width modulated (PWM) signal in response to the pulse sequence to produce at least one adjusted PWM output signal; wherein spectral energy of a carrier signal of the at least one adjusted PWM output signal at a carrier frequency of the carrier signal and harmonics of the carrier frequency is changed such that the at least one adjusted PWM output signal has a spectral shape defined by the particular spectral shape. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A circuit comprising:
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a data generator including a signal input to a first circuit configured to apply a signal transfer function, a noise input to a second circuit configured to apply a noise transfer function, and an output for providing a bit sequence, the signal input configured to receive a first input signal that is substantially constant, the noise input configured to receive a second input signal; a logic circuit to selectively apply a carrier suppression operation to at least one pulse-width modulated (PWM) signal in response to receiving the bit sequence to produce at least one adjusted PWM output signal, the at least one modulated PWM output signal having an adjusted spectral shape relative to a spectral shape of the at least one PWM signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method comprising:
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receiving at least one pulse-width modulated (PWM) signal from a PWM source; receiving a bit sequence having a particular spectral shape from a data generator; and selectively applying a carrier suppression operation to at least one PWM signal according to the bit sequence to produce at least one modulated PWM output signal with an adjusted spectral shape relative to a spectral shape of the at least one PWM signal. - View Dependent Claims (21, 22, 23)
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Specification