Abstract: A transmitter is adapted to be programmed to select an amplifier operating class for the transmitter out of a plurality of amplifier operating classes. The transmitter is also adapted to operate according to the selected amplifier operating class to communicate a signal to an antenna.

Abstract: A clock synthesis circuit includes a delta sigma modulator that receives a divide ratio and generates an integer portion and a digital quantization error (a fractional portion). A fractional-N divider divides a received signal according to a divide control value corresponding to the integer portion and generates a divided signal. A phase interpolator adjusts a phase of the divided signal according to the digital quantization error to thereby reduce noise associated with the fractional-N divider.

Abstract: A power control circuit is coupled to receive a feedback signal from a power amplifier (PA) and generate a control signal to control a variable gain amplifier (VGA) coupled to an input to the PA based on the feedback signal. The power control circuit may include, in one embodiment, a mute circuit to generate a mute signal to be provided to the VGA when the control signal is less than a first level and a clamp circuit to clamp a control voltage used to generate the control signal from exceeding a threshold level.

Abstract: A power control circuit is coupled to receive a feedback signal from a power amplifier (PA) and generate a control signal to control a variable gain amplifier (VGA) coupled to an input to the PA based on the feedback signal. The power control circuit may include, in one embodiment, a mute circuit to generate a mute signal to be provided to the VGA when the control signal is less than a first level and a clamp circuit to clamp a control voltage used to generate the control signal from exceeding a threshold level.

Abstract: In one form, a power converter for a power detector or the like includes first and third transistors of a first conductivity type, and second and fourth transistors of a second conductivity type. A control electrode of the first transistor receives a first bias voltage plus a positive component of a differential input signal. The second transistor is coupled in series with the first transistor and has a control electrode receiving a second bias voltage plus a negative component of the differential input signal. The third transistor is biased using the first bias voltage plus the negative component. The fourth transistor is coupled in series with the third transistor and is biased using the second bias voltage plus the positive component. A common interconnection point of the first and third transistors forms an output node.

Abstract: In one form, a power converter for a power detector or the like includes first and third transistors of a first conductivity type, and second and fourth transistors of a second conductivity type. A control electrode of the first transistor receives a first bias voltage plus a positive component of a differential input signal. The second transistor is coupled in series with the first transistor and has a control electrode receiving a second bias voltage plus a negative component of the differential input signal. The third transistor is biased using the first bias voltage plus the negative component. The fourth transistor is coupled in series with the third transistor and is biased using the second bias voltage plus the positive component. A common interconnection point of the first and third transistors forms an output node.

Abstract: A transmitter is adapted to be programmed to select an amplifier operating class for the transmitter out of a plurality of amplifier operating classes. The transmitter is also adapted to operate according to the selected amplifier operating class to communicate a signal to an antenna.

Abstract: A technique includes generating an angle modulated square wave signal and progressively filtering the angle modulated square wave signal in a transmitter using a plurality of low pass filters to produce a modulated sinusoidal signal to drive an antenna. The technique includes programming the transmitter to tune a corner frequency of the filtering to a frequency within a range of frequencies selectable using the programming, based on a carrier frequency associated with the modulated sinusoidal signal.

Abstract: In one form, a power detector includes first and third transistors of a first conductivity type, and second and fourth transistors of a second conductivity type. A control electrode of the first transistor receives a first bias voltage plus a positive component of a differential input signal. The second transistor is coupled in series with the first transistor and has a control electrode receiving a second bias voltage plus a negative component of the differential input signal. The third transistor is biased using the first bias voltage plus the negative component. The fourth transistor is coupled in series with the third transistor and is biased using the second bias voltage plus the positive component. A common interconnection point of the first and third transistors forms an output node. In another form, a power detector compares an output of a power detector core to multiple threshold voltages in corresponding comparators.

Abstract: In one form, a power detector includes first and third transistors of a first conductivity type, and second and fourth transistors of a second conductivity type. A control electrode of the first transistor receives a first bias voltage plus a positive component of a differential input signal. The second transistor is coupled in series with the first transistor and has a control electrode receiving a second bias voltage plus a negative component of the differential input signal. The third transistor is biased using the first bias voltage plus the negative component. The fourth transistor is coupled in series with the third transistor and is biased using the second bias voltage plus the positive component. A common interconnection point of the first and third transistors forms an output node. In another form, a power detector compares an output of a power detector core to multiple threshold voltages in corresponding comparators.

Abstract: A clock synthesis circuit includes a delta sigma modulator that receives a divide ratio and generates an integer portion and a digital quantization error (a fractional portion). A fractional-N divider divides a received signal according to a divide control value corresponding to the integer portion and generates a divided signal. A phase interpolator adjusts a phase of the divided signal according to the digital quantization error to thereby reduce noise associated with the fractional-N divider.

Abstract: A clock synthesis circuit includes a delta sigma modulator that receives a divide ratio and generates an integer portion and a digital quantization error (a fractional portion). A fractional-N divider divides a received signal according to a divide control value corresponding to the integer portion and generates a divided signal. A phase interpolator adjusts a phase of the divided signal according to the digital quantization error to thereby reduce noise associated with the fractional-N divider.

Abstract: A first phase-locked loop (PLL) circuit includes an input for receiving a timing reference signal from an oscillator, a controllable oscillator circuit supplying an oscillator output signal, and a multi-modulus feedback divider circuit. A second control loop circuit is selectably coupled through a select circuit to supply a digital control value (M) to the multi-modulus feedback divider circuit of the first loop circuit to thereby control the oscillator output signal. While the second control loop is coupled to supply the control value to the feedback divider circuit, the control value is determined according to a detected difference between the oscillator output signal and a reference signal coupled to the second control loop circuit at a divider circuit.

Abstract: A technique for expanding an input signal includes receiving the input signal at a first node of a voltage expander and generating a plurality of expanded signals on different outputs of the voltage expander responsive to the input signal. In certain embodiments, each of the expanded signals has a different magnitude at a respective fixed offset from the input signal.

Abstract: In a feedback system such as a PLL, the integrating function associated with a loop filter capacitor is instead implemented digitally and is easily implemented on the same integrated circuit die as the PLL. There is no need for either an external loop filter capacitor nor for a large loop filter capacitor to be integrated on the same integrated circuit die as the PLL. In some embodiments, an analog phase detector is utilized whose phase error output signal is delta-sigma modulated to encode the magnitude of the phase error using a digital (i.e., discrete-time and discrete-value) signal. This digital phase error signal is “integrated” by a digital integration block including, for example, a digital accumulator, whose output is then converted to an analog signal, optionally combined with a loop feed-forward signal, and then conveyed as a control voltage to the voltage-controlled oscillator.

Abstract: A communications device including communications circuitry, tunable filter circuitry including a node configured to pass a signal between an antenna and the communication circuitry, and control circuitry configured to cause energy in the tunable filter circuitry to be adjusted for a time period and configured to determine a resonant frequency of the tunable filter circuitry from oscillations on the node caused by the energy subsequent to the time period is provided.

Abstract: Embodiments of the present invention may provide for independent setting of jitter tolerance and jitter transfer levels, and reduced jitter generation of a data transmission device, such as a clock and data recovery (CDR) circuit or the like. An architecture may provide for reconfigurability of a circuit for use in various applications. The architecture may include a multi-loop structure, such as a tri-loop structure.

Abstract: A first phase-locked loop (PLL) circuit includes an input for receiving a timing reference signal from an oscillator, a controllable oscillator circuit supplying an oscillator output signal, and a multi-modulus feedback divider circuit. A second control loop circuit is selectably coupled through a select circuit to supply a digital control value (M) to the multi-modulus feedback divider circuit of the first loop circuit to thereby control the oscillator output signal. While the second control loop is coupled to supply the control value to the feedback divider circuit, the control value is determined according to a detected difference between the oscillator output signal and a reference signal coupled to the second control loop circuit at a divider circuit.

Abstract: A clock synthesis circuit includes a delta sigma modulator that receives a divide ratio and generates an integer portion and a digital quantization error (a fractional portion). A fractional-N divider divides a received signal according to a divide control value corresponding to the integer portion and generates a divided signal. A phase interpolator adjusts a phase of the divided signal according to the digital quantization error to thereby reduce noise associated with the fractional-N divider.

Abstract: A feedback system such as a phase locked loop (PLL) includes a second feedback loop which responds when a VCO control voltage is near either end of its range, by slowly adjusting additional tuning elements which control the VCO frequency. The second feedback loop is arranged to cause a slow enough change in the VCO frequency that the first traditional feedback loop adjusts the control voltage quickly enough in a direction toward its mid-range value to keep the VCO frequency substantially unchanged. The second feedback loop advantageously incorporates one or more digital control signals which preferably change no more than one bit at a time and with a controlled slow ramp rate. As a result, the PLL maintains phase accuracy so that the operation of the PLL, including subtle specifications such as input data jitter tolerance or output jitter generation when used for clock and data recovery applications, is not negatively impacted.