Abstract: An integrated circuit may have two signal paths: an open-loop modulator (which may comprise a digital-input Class-D amplifier) and a closed-loop modulator (which may comprise an analog-input Class-D amplifier). A control subsystem may be capable of selecting either of the open-loop modulator or the closed-loop modulator as a selected path based on one or more characteristics (e.g., signal magnitude) of an input audio signal. For example, for higher-magnitude signals, the closed-loop modulator may be selected while the open-loop modulator may be selected for lower-magnitude signals. In some instances, when the open-loop modulator is selected as the selected path, the closed-loop modulator may power off, which may reduce power consumption. In addition, one or more techniques may be applied to reduce or eliminate user-perceptible audio artifacts caused by switching between the open-loop modulator and the closed-loop modulator, and vice versa.

Abstract: A system may include a charge pump configured to operate in a plurality of modes including a first mode in which the ratio of an output voltage to an input voltage of the charge pump is a first ratio and a second mode in which the ratio is a second ratio and a controller configured to limit current flowing between a power source of the charge pump to the charge pump, wherein the power source provides the input voltage, by limiting a transfer of charge between the power source and the charge pump during a switching cycle of the charge pump responsive to a change in operation between modes of the plurality of modes.

Abstract: In accordance with embodiments of the present disclosure, a system may include a series combination of a boost converter and a power converter coupled together in series, such that the series combination boosts an input voltage to the series combination to an output voltage greater than the input voltage such that a voltage boost provided by the series combination is greater than a voltage boost provided by the boost converter alone. The system may also include an amplifier, wherein an input of the amplifier is coupled to an output of the series combination of the boost converter and the power converter.

Abstract: A method of increasing a multiplication ratio of a charge pump, the multiplication ratio defining a relationship between an output voltage of the charge pump and an input voltage of the charge pump, comprising: analyzing a first efficiency of the charge pump when the multiplication ratio is at a first ratio, calculating a second efficiency of the charge pump when the multiplication ratio is a second ratio lesser than the first ratio, and based on the first efficiency and the second efficiency, determining at least one of a target output power and a target output voltage at which to change the multiplication ratio from the second ratio to the first ratio.

Abstract: A method of increasing a multiplication ratio of a charge pump, the multiplication ratio defining a relationship between an output voltage of the charge pump and an input voltage of the charge pump, comprising: analyzing a first efficiency of the charge pump when the multiplication ratio is at a first ratio, calculating a second efficiency of the charge pump when the multiplication ratio is a second ratio lesser than the first ratio, and based on the first efficiency and the second efficiency, determining at least one of a target output power and a target output voltage at which to change the multiplication ratio from the second ratio to the first ratio.

Abstract: In accordance with embodiments of the present disclosure, a system may include a series combination of a boost converter and a power converter coupled together in series, such that the series combination boosts an input voltage to the series combination to an output voltage greater than the input voltage such that a voltage boost provided by the series combination is greater than a voltage boost provided by the boost converter alone. The system may also include an amplifier, wherein an input of the amplifier is coupled to an output of the series combination of the boost converter and the power converter.

Abstract: A system may include a charge pump configured to operate in a plurality of modes including a first mode in which the ratio of an output voltage to an input voltage of the charge pump is a first ratio and a second mode in which the ratio is a second ratio and a controller configured to limit current flowing between a power source of the charge pump to the charge pump, wherein the power source provides the input voltage, by limiting a transfer of charge between the power source and the charge pump during a switching cycle of the charge pump responsive to a change in operation between modes of the plurality of modes.

Abstract: In accordance with embodiments of the present disclosure, a method for identifying a location of an integrated circuit that is sensitive to RTS noise may include applying localized heat to a scan area of the integrated circuit, observing any change in one or more electrical parameters of the integrated circuit in response to the localized heat being applied to the scan area indicative of sensitivity to RTS noise, and identifying the location sensitive to RTS noise responsive to observing change in one or more electrical parameters of the integrated circuit indicative of sensitivity to RTS noise in response to the localized heat being applied to the scan area.

Abstract: In accordance with embodiments of the present disclosure, a method for identifying a location of an integrated circuit that is sensitive to RTS noise may include applying localized heat to a scan area of the integrated circuit, observing any change in one or more electrical parameters of the integrated circuit in response to the localized heat being applied to the scan area indicative of sensitivity to RTS noise, and identifying the location sensitive to RTS noise responsive to observing change in one or more electrical parameters of the integrated circuit indicative of sensitivity to RTS noise in response to the localized heat being applied to the scan area.