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 programmable-gain amplifier includes: two complementary cross-coupled transistor pairs mutually coupled with each transistor in one pair having a current flow path cascaded with a current flow path of a respective one of the transistors in the other pair. First and second coupling points are formed between the pairs; with first and second sampling capacitors coupled thereto. First and second input stages have input terminals to input signals for sampling by the first and second sampling capacitors. Switching means couple the first and second input stages to the sampling capacitors so the input signals are sampled as sampled signals on the sampling capacitors. The switching means energizes the complementary cross-coupled transistor pairs so the signals sampled on the sampling capacitors undergo negative resistance regeneration growing exponentially over time to thereby provide an exponential amplifier gain.

A duty cycle correction circuit may include: a phase mixing section capable of mixing a first integrated signal generated by integrating a positive clock signal, with a first compensation signal generated by differentiating and integrating the positive clock signal and a negative clock signal, respectively, to generate a first phase-mixed signal, and mixing a second integrated signal generated by integrating the negative clock signal, with a second compensation signal generated by integrating and differentiating the positive clock signal and the negative clock signal, respectively, to generate a second phase-mixed signal; and a noise removal section capable of receiving and removing a common mode noise between the first phase-mixed signal and the second phase-mixed signal by adjusting a cross-point therebetween, and outputting first and second duty-corrected clock signals.

At least some embodiments are directed to a system comprising an amplifier containing a first bias current source and configured to provide an output voltage at a node, a gain stage coupled to the node and comprising a second bias current source, and a buffer stage coupled to the node and comprising third and fourth bias current sources and an additional set of bias current sources, the third and fourth bias current sources are able to activate output transistors that are configured to increase current provided to a load. The system also comprises a controller configured to activate the first bias current source, to activate the second bias current source after the first bias current source is activated, to activate the bias current sources in the set after the first bias current source is activated, and to activate the third and fourth bias current sources after the first and second bias current sources are activated and after the bias current sources in the set are activated.

A linear low noise amplifier is disclosed. In at least one exemplary embodiment, the linear low noise amplifier may include a first metal oxide semiconductor field effect transistor (MOSFET) configured to operate in a triode mode coupled to a second MOSFET configured to operate in a saturation mode. Linearity of the low noise amplifier may be determined, at least in part, by a transconductance associated with the second MOSFET and a channel resistance associated the first MOSFET.

A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage.

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 variable-gain power amplifying technique includes generating, with a network of one or more reactive components included in an oscillator, a first oscillating signal, and outputting, via one or more taps included in the network of the reactive components, a second oscillating signal. The second oscillating signal has a magnitude that is proportional to and less than the first oscillating signal. The power amplifying technique further includes selecting one of the first and second oscillating signals to use for generating a power-amplified output signal, and amplifying the selected one of the first and second oscillating signals to generate the power-amplified output signal.

A power amplification module includes a first input terminal that receives a first transmit signal in a first frequency band, a second input terminal that receives a second transmit signal in a second frequency band having a narrower transmit/receive frequency interval than the first frequency band, a first amplification circuit that receives and amplifies the first transmit signal to produce a first amplified signal and outputs the first amplified signal, a second amplification circuit that receives and amplifies the second transmit signal to produce a second amplified signal and outputs the second amplified signal, a third amplification circuit that receives and amplifies the first or second amplified signal to produce an output signal and outputs the output signal, and an attenuation circuit located between the second input terminal and the second amplification circuit and configured to attenuate a receive frequency band component of the second frequency band.