The use of digital-to-analog converter technology is well known and widely used to convert information from a stream of digital information such as voice or data into an analog signal. Once in the analog domain, signals can either be applied to any type of filter, mixer or speaker so that the analog signals can be heard and/or interpreted by a machine or the human ear or they may be mixed with another analog signal and transmitted.
Prior art signal generation topologies such as used with a DAC often were designed for situations to provide the best possible analog information for a given digital signal. This “over design” results both in a greater degree of circuit design area and an excessive current drain on a portable device that might use the DAC. In many instances, the DAC may be interpreting digital information having a very low bit resolution while still operating as if the incoming digital information uses a digital protocol having a high bit resolution.
Moreover, many digital protocols do not require low noise or low intermodulation distortion products, yet the DAC and other signal processing components still process all incoming digital information in the same fashion. This often requires a greater degree of mathematical computation, processing, higher signal drive capability, higher clock speed and an overall greater current demand on a portable device using these components. In many instances, the DAC has been required to operate in this manner to meet published Telecommunications Industry Association (TIA) communications standards where a high-quality analog output signal is required to be produced from a high-resolution digital signal. Although the best digital-to-analog matching is not always required, the DAC and other processing components are operationally fixed for best case digital signaling conditions in order to produce the highest quality analog output. This approach becomes costly since the analog output from the DAC cannot be dynamically changed based on the type of digital signal received and the quality of analog output that is required.
Thus, the need exists to provide an adaptive system and method used with a DAC and other signaling processing components to dynamically control their dynamic range, output drive capability, signal amplitude swing and spectral content. The adaptive system should allow the signal processing requirements of these devices to be dynamically varied. This will enable the most efficient use of power in a portable communications device in order to best accommodate the type of digital information received and the quality of analog output required for a given digital input. This will enable the DAC and signaling processing components to conserve power when a high-quality analog output is not required, thereby allowing a portable communications device to dynamically manage its power consumption.