Abstract: Embodiments of integrated circuits for use in a broadband tuner are described. In one embodiment, an integrated circuit includes a clock buffer configured to buffer a received clock signal and generate a buffered clock signal. Additionally, the integrated circuit includes a multiphase local oscillator core coupled to the clock buffer and configured to generate a plurality of oscillator signals in response to the buffered clock signal, each of the plurality of oscillator signals being mutually phase shifted. The integrated circuit may also include a plurality of output buffers, each configured to receive one of the plurality of oscillator signals and to produce an output signal suitable for use in a broadband tuner circuit in response to the one of the plurality of oscillator signals.

Abstract: A signal generation power management control system (100) for use in a portable communications device includes a digital signal processor (DSP) (101) for processing a digital source input and providing a digital processed bit stream A digital-to-analog converter (DAC) (103) is used for converting the digital processed bit stream to provide an analog signal. A power management controller (115) within the DSP (101) is then used for interpreting control parameters of signal processing components used within the portable communications device and dynamically adjusting the bias current of these components based on minimal signal requirements of the analog signal.

Abstract: A wide linear range peak detector including first and second peak detectors and a compensation circuit. The first peak detector receives an input signal and has an output providing a first peak signal approximation which approximates a peak level of the input signal. The first peak signal approximation includes a non-linear portion which is a function of the peak level of the input signal. The second peak detector also receives the input signal and has an output providing a second peak signal approximation. The compensation circuit uses the second peak signal approximation to provide a compensation signal which compensates the non-linear portion of the first peak signal approximation. In particular, the second peak signal is used to generate the compensation signal to approximate and cancel the non-linear portion.

Abstract: A method and system controls transmit power by combining the advantages of digital attenuation and analog baseband step attenuators by calibration to overcome the limitations of analog step attenuators. The calibration technique uses highly accurate digital attenuators to determine the actual sizes of the analog steps as analog step attenuator is stepped through a range of attenuation levels. A method of calibration accurately measures attenuation steps comparison to a digital attenuator so that the attenuation actually realized by the analog step attenuator is accurately known. Therefore, the difference between the attenuation realized by the analog step attenuator and the desired attenuation is accurately known. The difference is realized in the digital attenuator and the attenuation resulting from the composite of the digital and analog step attenuator can very accurately realize the requested attenuation.

Abstract: A sigma-delta DAC circuit 10 includes a sigma-delta modulator 12 for producing and outputting an n-bit digital signal representative of an input analog signal, wherein n is a positive integer greater than 1, and is preferably equal to 4, 5 or 6. A differential n-bit DAC 30 is for converting a 2n−1-bit digital signal and a 2n−1-bit inverted digital signal processed and output by a bit shifter 24 and a differential decoder 18 to a differential analog signal. The sigma-delta modulator has a movable zero for enabling dynamic spectral shaping of the differential analog signal.

Abstract: An auto-adapt circuit (200) for altering radio receiver parameters due to demodulator transients and preventing the loss of received information. The auto-adapt circuit includes a detector circuit (215) connected to the output of a receiver demodulator (203) and a switch (219) controlled by the detector circuit (215). The detector circuit (215) detects a transient voltage at an upper threshold limit or at a lower threshold limit such that a transient at an output of the receiver demodulator will actuate the at least one switch for varying demodulator coupling parameters of the radio receiver.