| Patent application number | Description | Published |
|---|
| 20090243745 | SYSTEM AND METHOD OF SHAPING A POWER SPECTRUM IN PWM AMPLIFIERS - 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. | 10-01-2009 |
| 20090289708 | Predictive feedback compensation for PWM switching amplifiers - Methods and systems are disclosed for predictive feedback compensation (PFC) circuitry for suppressing distortions caused by supply voltage variations and output amplitude switching non-idealities in pulse width modulated (PWM) switching amplifiers by pre-compensating the PWM input based upon the supply voltage or output pulse amplitude. Output amplitude errors associated with previous PWM output signals are used to predict output amplitude errors expected for future PWM output signals. These predicted output amplitude errors are then used to adjust the pulse widths for the future PWM output signals. Traditional feedback techniques can also be used in conjunction with the predictive feedback compensation (PFC) circuitry. | 11-26-2009 |
| 20090289709 | Closed loop timing feedback for PWM switching amplifiers using predictive feedback compensation - Methods and systems are disclosed for closed loop feedback for pulse width modulated (PWM) switching amplifiers using predictive feedback compensation (PFC) for suppressing distortions caused by supply voltage variations and output amplitude switching non-idealities in pulse width modulated (PWM) switching amplifiers by pre-compensating the PWM input based upon the supply voltage or output pulse amplitude and using closed loop timing feedback. Output amplitude errors associated with previous PWM output signals are used to predict output amplitude errors expected for future PWM output signals. These predicted output amplitude errors are then used to adjust the pulse widths for the future PWM output signals. Timing differences between pulse widths for the uncompensated PWM input signal and the pre-compensated PWM signal are used as feedback to provide closed loop width adjustment. | 11-26-2009 |
| 20100171540 | System and Method of Changing a PWM Power Spectrum - In a particular embodiment, a circuit device includes a pulse edge control circuit to receive at least one pulse-width modulated (PWM) signal from a PWM source. The pulse edge control circuit is adapted to selectively invert and swap the at least one PWM signal with a logic-inverted duty-cycle complement of the at least one PWM signal at discrete time intervals to produce at least one modulated PWM signal having a changed power spectrum. The pulse edge control circuit provides the at least one modulated PWM signal to at least one output of the pulse edge control circuit. | 07-08-2010 |
| 20100207699 | System and Method of Shaping a Power Spectrum in PWM Amplifiers - 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. | 08-19-2010 |
| 20100296671 | System and Method of Changing a PWM Power Spectrum - In a particular embodiment, a circuit device includes a pulse edge control circuit to receive at least one pulse-width modulated (PWM) signal from a PWM source. The pulse edge control circuit is adapted to selectively apply a phase shift operation to the at least one PWM signal at integer submultiples of a frame repetition rate to produce at least one modulated PWM signal having a changed power spectrum. The pulse edge control circuit provides the at least one modulated PWM signal to at least one output of the pulse edge control circuit. | 11-25-2010 |
| 20110298505 | LATENCY LOCKED LOOP CIRCUIT FOR DRIVING A BUFFER CIRCUIT - In an embodiment, a circuit includes a buffer circuit including a buffer input and an output terminal and a latency locked loop (LLL) circuit. The LLL circuit includes a signal input for receiving an input signal, a feedback input coupled to the output terminal, and a signal output coupled to the buffer input. The LLL circuit is configured to control a propagation delay between the signal input and the signal output to produce a substantially constant total delay from the signal input to the output terminal. | 12-08-2011 |
| 20110298509 | TIME-SHARED LATENCY LOCKED LOOP CIRCUIT FOR DRIVING A BUFFER CIRCUIT - In an embodiment, a device includes a buffer circuit with first and second buffer outputs and a latency locked loop (LLL) circuit. The LLL circuit includes first and second LLL inputs for receiving first and second input signals and includes at least one shared component that is time shared. The at least one shared component is configured to measure edge timing errors in output signals on the first and second buffer outputs relative to the first and second inputs signals and to generate delay adjustment signals to adjust timing of edge transitions within the first and second input signals provided to the buffer circuit to control a total propagation delay from the first and second LLL inputs to the first and second buffer outputs. | 12-08-2011 |
