Patent classifications
H03M1/66
Audio processing device
To prevent that the noise occurs at timing switching between PCM data and DSD data by a simple configuration. An AV receiver 1 includes a mute circuit 5 that mutes output from a DAC 4, a detection circuit 6 that detects that a digital audio signal is zero data and supplies a detection signal, a microcomputer 2 that supplies a control signal at timing switching from PCM data to DSD data before switches from PCM mode that the DAC 4 converts PCM data into an analog audio signal to DSD mode that the DAC 4 converts DSD data into the analog audio signal, and an AND circuit 7 that activates the mute circuit 5 in case that the detection signal from the detection circuit 6 and the control signal from the microcomputer 2 are supplied.
Audio processing device
To prevent that the noise occurs at timing switching between PCM data and DSD data by a simple configuration. An AV receiver 1 includes a mute circuit 5 that mutes output from a DAC 4, a detection circuit 6 that detects that a digital audio signal is zero data and supplies a detection signal, a microcomputer 2 that supplies a control signal at timing switching from PCM data to DSD data before switches from PCM mode that the DAC 4 converts PCM data into an analog audio signal to DSD mode that the DAC 4 converts DSD data into the analog audio signal, and an AND circuit 7 that activates the mute circuit 5 in case that the detection signal from the detection circuit 6 and the control signal from the microcomputer 2 are supplied.
Accurate, low-power power detector circuits and related methods
Embodiments of power detector circuits and related methods to compensate for undesired DC offsets generated within power detector circuits are disclosed. Input signals having input frequencies are received and converted to a magnitude signal, and reference signals are also generated. The magnitude signal may include a DC component proportional to a power of the input signal along with undesired DC offsets. The reference signal may include a DC component proportional to a power of at least one input reference signal along with undesired DC offsets. To compensate for errors introduced by the DC offsets, a DC offset calibration signal or a gain are determined in a calibration mode and then applied in a normal mode to compensate for the DC offsets. For the calibration mode, a difference between the magnitude signal and the reference signal is compared to a threshold value to generate a power detection output signal.
Accurate, low-power power detector circuits and related methods
Embodiments of power detector circuits and related methods to compensate for undesired DC offsets generated within power detector circuits are disclosed. Input signals having input frequencies are received and converted to a magnitude signal, and reference signals are also generated. The magnitude signal may include a DC component proportional to a power of the input signal along with undesired DC offsets. The reference signal may include a DC component proportional to a power of at least one input reference signal along with undesired DC offsets. To compensate for errors introduced by the DC offsets, a DC offset calibration signal or a gain are determined in a calibration mode and then applied in a normal mode to compensate for the DC offsets. For the calibration mode, a difference between the magnitude signal and the reference signal is compared to a threshold value to generate a power detection output signal.
Duty cycle adjustment circuit
A duty cycle adjustment circuit includes: a delay circuit to delay an input clock signal to produce a delayed clock signal having a rising edge partially overlapping the rising edge of the input clock signal, the input clock signal oscillating between first and second values about a midpoint value; a blender circuit to blend the input clock signal and the delayed clock signal to produce a blended clock signal; a buffer circuit to buffer the input clock signal for an amount of time comparable to the blender circuit, to produce a buffered clock signal; and a combiner circuit to combine the buffered and the blended clock signals to produce an output clock signal that transitions to or remains at the first value when both the buffered and blended clock signals are on the first value side of the midpoint value, and otherwise transitions to or remains at the second value.
Digital-to-analog converter
A digital-to-analog converter (DAC) circuit includes a first DAC that produces a first analog output signal based upon a received multi-bit digital signal and upon a received clock. A second DAC that produces a second analog output signal based upon the received multi-bit digital signal and upon the received clock, wherein the first and second DACs are connected in parallel and process the same multi-bit digital signal. In one embodiment, the DACs produce differential signals. A low pass filter connected to receive the first and second analog outputs is configured to sum the first and second analog outputs and to filter the summed first and second analog outputs to produce an ingoing analog signal. An amplifier is connected to receive the ingoing analog signal to produce an amplified ingoing analog signal.
PARAMETER CORRECTION FOR CASCADED SIGNAL COMPONENTS
Various examples are directed to systems and methods for providing correction to cascaded signal components. A correction signal may be applied to multiple signal components in a set of cascaded signal components.
PARAMETER CORRECTION FOR CASCADED SIGNAL COMPONENTS
Various examples are directed to systems and methods for providing correction to cascaded signal components. A correction signal may be applied to multiple signal components in a set of cascaded signal components.
Current injection for fast ramp start-up during analog-to-digital operations
An example method for fast ramp start-up during analog to digital conversion (ADC) includes opening a feedback bypass switch coupled to an amplifier to initiate an ADC operation, providing an injection current pulse to an inverting input of the amplifier, where the non-inverting input is coupled to a feedback bypass switch, integrating a first reference current coupled to the inverting input of the amplifier, where the integrating of the first reference current occurs due to the opening of the feedback bypass switch, and providing a reference voltage in response to the injection current pulse, the integrating of the first reference current, and a reference voltage coupled to a non-inverting input of the amplifier, where a level of the reference voltage is increased at least at initiation of the ADC operation in response to the injection current pulse.
Current injection for fast ramp start-up during analog-to-digital operations
An example method for fast ramp start-up during analog to digital conversion (ADC) includes opening a feedback bypass switch coupled to an amplifier to initiate an ADC operation, providing an injection current pulse to an inverting input of the amplifier, where the non-inverting input is coupled to a feedback bypass switch, integrating a first reference current coupled to the inverting input of the amplifier, where the integrating of the first reference current occurs due to the opening of the feedback bypass switch, and providing a reference voltage in response to the injection current pulse, the integrating of the first reference current, and a reference voltage coupled to a non-inverting input of the amplifier, where a level of the reference voltage is increased at least at initiation of the ADC operation in response to the injection current pulse.