In some embodiments, a method for processing an audio signal in an audio processing apparatus is disclosed. The method includes receiving an audio signal and a parameter, the parameter indicating a location of an auditory event boundary. An audio portion between consecutive auditory event boundaries constitutes an auditory event. The method further includes applying a modification to the audio signal based in part on an occurrence of the auditory event. The parameter may be generated by monitoring a characteristic of the audio signal and identifying a change in the characteristic.

In some embodiments, a method for processing an audio signal in an audio processing apparatus is disclosed. The method includes receiving an audio signal and a parameter, the parameter indicating a location of an auditory event boundary. An audio portion between consecutive auditory event boundaries constitutes an auditory event. The method further includes applying a modification to the audio signal based in part on an occurrence of the auditory event. The parameter may be generated by monitoring a characteristic of the audio signal and identifying a change in the characteristic.

A method of controlling bandwidth and peaking over gain in a variable gain amplifier (VGA) device and structure therefor. The device includes at least three differential transistor pairs configured as a cross-coupled differential amplifier with differential input nodes, differential bias nodes, differential output nodes, a current source node, and two cross-coupling nodes. The cross-coupled differential amplifier includes a load resistor coupled to each of the differential output nodes and one of the cross-coupling nodes, and a load inductor coupled to the each of the cross-coupling nodes and a power supply rail. A current source is electrically coupled to the current source node. The cross-coupling configuration with the load resistance and inductance results in a lower bandwidth and lowered peaking at low gain compared to high gain. Further, the tap point into the inductor can be chosen as another variable to tune the bandwidth and peaking in a communication system.

An LNA having a plurality of paths, each of which can be controlled independently to achieve a gain mode. Each path includes at least an input FET and an output FET coupled in series. A gate of the output FET is controlled to set the gain of the LNA. Signals to be amplified are applied to the gate of the input FET. Additional stacked FETs are provided in series between the input FET and the output FET.

The present invention provides a system and method for operating hybrid concurrent and switched dual-band low noise amplifiers. Embodiments use a concurrent design at the input block of a hybrid LNA to advantageously achieve better impedance matching while using a switch capacitor design at the output block to advantageously achieve a better gain than typical concurrent multiband LNAs. Embodiments might be integrated into wireless devices configured to simultaneously receive on multiple frequency bands while providing gains of 30 dB or more by combining the advantages of concurrent multiband LNAs with the advantages of switched multiband LNAs. In addition to the higher gains provided by embodiments of the hybrid LNA described herein, hybrid multiband LNAs according to embodiments of the present invention provide a smaller device footprint and power requirements than would be required for a receiver including multiple single-band LNAs for amplifying signals for each frequency band individually.

A method includes generating a gain transition signal in response to any one of an average value of a feedback signal, a slope of the feedback signal, a slope of an input signal of the power converter, a maximum value of the input signal, and a minimum value of the input signal, and generating a first gain control signal and a second gain control signal in response to the gain transition signal. A gain transition controller includes a transition signal generator generating the gain transition signal and a gain control signal generator generating the first gain control signal and the second gain control signal in response to the gain transition signal.

The present disclosure provides a power amplifier circuit capable of suppressing the occurrence of noises while enabling control of an output power level. The power amplifier circuit includes a first transistor that amplifies a first signal; a bias circuit that supplies a bias current or voltage based on a control signal to the first transistor; a second transistor to which a control current based on the control signal is supplied, which has an emitter or a source thereof connected to a collector or a drain of the first transistor, and from which a second signal obtained by amplifying the first signal is output; and a first feedback circuit provided between the collector or the drain of the second transistor and the base or the gate of the second transistor.

A combined resistance circuit 2A includes a first circuitry 20A provided between a first end 2a and a second end 2b. This first circuitry 20A includes a resistor R1 provided between a node N11 and a node N12, a resistor R2 provided between the node N12 and a node N13, a resistor R3 provided between the node N13 and a node N14, a resistor R4 provided between the node N14 and the node N11, a resistor R5 provided between the node N11 and the node N13, a switch SW0 provided in series to the resistor R4 between the node N14 and the node N11, and a switch SW1 provided in series to the resistor R2 between the node N12 and the node N13. The node N12 is connected to the first end and the node N14 is connected to the second end.

A gain stage includes an offset cancellation loop coupled to a first amplifier. The first amplifier has a first transfer function and a first gain, and the offset cancellation loop includes a second amplifier having a second transfer function and a second gain. The second transfer function is based on an inverse of the first transfer function and the second gain based on an inverse of the first gain. When the offset cancellation loop feeds back an output signal of the first amplifier to an input of the first amplifier, a high-pass pole (or high-pass corner frequency) of the first amplifier is maintained at a constant level in spite of variations in the gain of the first amplifier. In one case, the second amplifier in the offset cancellation loop may be a simpler and lower power version of the first amplifier.

A differential pair of transistors receives input voltages. Current mirror transistors and cascode transistors are coupled to the differential pair of transistors. The differential pair of transistors is coupled between the cascode transistors and a tail transistor that draws a first bias current from a tail node, the first bias current having a magnitude equal to a product of a total bias current and a constant that is less than one. A first current source transistor draws a second bias current from a node between the differential pair and cascode transistors so the second bias current bypasses one transistor of the differential pair of transistors. The second bias current has a magnitude equal to a product of the total bias current and a value equal to one minus the constant. An output stage is biased by an output at node between the cascode transistors and the current mirror transistors.