Abstract: During operation of a boost converter conditions may exist that result in a reverse current through the boost converter, such as when a load drop from the boost converter occurs. During the reverse current period, inductance value determinations made during a forward current period may be used to estimate a magnitude of the reverse current and this estimate used by a controller to control the boost converter and return the boost converter to normal operation. The controller may control the boost converter by changing a ratio of charging and discharging time for an inductor of the boost converter, decreasing a bandwidth of the boost converter, and/or increasing a resistance of the boost converter.

Abstract: Thermal levels in an inductor of a boost converter may be managed by implementing peak current limits for the boost converter. For example, an inductor may be allowed to conduct above a certain peak current limit for a certain period of time before the current is reduced by a controller to a low current limit. The controller may hold the low current limit in place for a certain period of time, after which the current through the inductor is allowed to again exceed the low current limit. However, if the high current limit is again exceeded or sustained for a certain period of time, the low current limit may be again imposed by the controller.

Abstract: Audio amplification may be improved by controlling an audio amplifier based on the audio signal being amplified. For example, when the audio signal level increases or decreases, a boost voltage provided to an audio amplifier by a boost converter may also be increased or decreased. In another example, when the audio signal level decrease below a certain level, the audio amplifier may be switched from amplifying the audio signal with a boost converter input to amplifying the audio signal with a low voltage input. Control of the audio amplifier may be implemented in a digital boost converter controller coupled to the boost converter and/or the audio amplifier.

Abstract: Audio amplification may be improved by controlling an audio amplifier based on the audio signal being amplified. For example, when the audio signal level increases or decreases, a boost voltage provided to an audio amplifier by a boost converter may also be increased or decreased. In another example, when the audio signal level decrease below a certain level, the audio amplifier may be switched from amplifying the audio signal with a boost converter input to amplifying the audio signal with a low voltage input. Control of the audio amplifier may be implemented in a digital boost converter controller coupled to the boost converter and/or the audio amplifier.

Abstract: Because of the natural ability to reject clock jitter, the SRC circuits include an internal oscillator to provide an operating clock signal. The internal oscillator can be operated independently of any external frequency control signal, including input and output frame clocks. The internal oscillator can be implemented as a relatively low-cost fixed frequency oscillator. The use of a relatively low precision, inexpensive internal oscillator in an SRC circuit reduces the overall cost of SRC circuits while providing acceptable performance. Accordingly, reducing costs of SRC circuits also has a positive cost/benefit affect on the digital signal processing systems that use SRC circuits.

Abstract: A stereo digital-to-analog converter is able to operate in an 8 pin package yet to operate under a variety of serial data input formats. The normal de-emphasis pin can be used for receiving a static de-emphasis signal, an external serial clock, or programming data for the serial data formats. In addition metal and wire bond options are used to provide more flexibility in the manufacturing process.