Abstract: A method and apparatus is provided for reducing interference in circuits. A management strategy is provided to reduce reference spurs and interference in circuits. The management strategy uses a combination of one or more techniques which reduce the digital current, minimize mutual inductance, utilize field cancellation, prevent leakage current, and/or manage impedance. These techniques may be used alone, or preferably, used on combination with one another.

Abstract: In one embodiment, a method for performing antenna diversity combining for digitally broadcast radio signals includes generating a first signal quality metric for a first signal obtained from an incoming digitally broadcast radio signal received in a first signal path, and similarly generating a second signal quality metric for a second signal obtained from the radio signal received in a second signal path. Then the first and second signals from these paths can be coherently combined based on the signal quality metrics to obtain a combined frequency domain symbol. In some embodiments, this combined frequency domain symbol may be remodulated to a time domain symbol. Also in some embodiments N tuners can be daisy chained to generate a final output that is either a frequency domain symbol of combined sub-carriers, soft bits to a forward error correction (FEC) decoder, or a remodulated time domain symbol. As a further possibility, each of the N tuners can use a different local oscillator (LO) frequency.

Abstract: A method for compensating for strain on a MEMS device includes generating a signal indicative of a strain on the MEMS device in a first mode of operating a system including the MEMS device. The method includes compensating for the strain in a second mode of operating the system based on the signal. Generating the signal may include comparing an indicator of a resonant frequency of the MEMS device to a predetermined resonant frequency of the MEMS device. Generating the signal may include comparing a first output of a strain-sensitive device to a second output of a strain-insensitive device and generating an indicator thereof. Generating the signal may include sensing a first capacitive transduction of strain-sensitive electrodes of the MEMS device in the first mode and generating the signal based thereon. The strain-sensitive electrodes of the MEMS device may be disabled in the second mode.

Abstract: A method includes receiving a desired channel indication in a radio tuner, determining a band of operation in which the channel is located, and if the channel is within a first band coupling multiple inductors into a resonant tank, and if the desired channel is within a second band coupling a single inductor into the resonant tank.

Abstract: Reference signal generators using thermistors are disclosed. An apparatus includes a first device having a first temperature coefficient and a thermistor having a second temperature coefficient having a sign opposite to that of the first temperature coefficient. A circuit maintains equivalence of a first signal and a second signal and offsets a first temperature variation of the first device using a second temperature variation of the thermistor to generate the second signal having a low temperature coefficient. The first device may be a bipolar transistor configured to generate a base-emitter voltage and coupled in series with the thermistor. The first signal may be a first voltage on a first node. The second signal may be a second voltage on a second node. The circuit may be configured to maintain effective equivalence of the first voltage and the second voltage. The apparatus may include a resistor coupled to the second node.

Abstract: Methods of reassembling a mesh network which has been disrupted by the unavailability of a node or a link are disclosed. Nodes continuously receive beacon messages originating from a leader node. These beacon messages may be transmitted directly by the leader node, or may have been retransmitted by an intermediate node. When a node determines that it has not received a beacon message in a certain time period, it concludes that it is now disconnected from that leader node. At this point, it may choose to act as a leader node and form a new network, or may join with another network. The determination of which network to join may be based on some indicia associated with the leader node of that network.

Abstract: A circuit may include a comparator having a first input, a second input, and an output. The circuit further may further include a successive approximation register (SAR) circuit coupled to the output of the comparator, the first input, and the second input. The SAR circuit may be configured to program one or more capacitors to selectively bias the first input to provide a single-ended measurement of a voltage at the second input.

Abstract: A frequency synthesizer capable of generating a clock signal having reduced digital spurs and reduced jitter is described. An apparatus includes a frequency modulator configured to generate a divide control signal and a digital quantization error signal in response to a divide ratio. The apparatus includes a phase modulator configured to generate a phase error signal based on the digital quantization error signal. The phase modulator is an n-order sigma-delta modulator module, n being an integer greater than one. The apparatus may include an interpolative divider configured to generate a feedback signal in a phase-locked loop (PLL) based on an output signal of the PLL, the divide control signal, and the phase error signal. The interpolative divider may include the frequency modulator and the phase modulator. The phase modulator may have a unity gain signal transfer function.

Abstract: A technique includes receiving data that is communicated in a frame over a wireless network and processing the data through a filter. A response of the filter is changed during the processing.

Abstract: A system such as a mechanically tuned radio can have a signal path to receive and process an incoming radio frequency (RF) signal and to provide the processed signal to a first analog-to-digital converter (ADC) to convert the processed signal to a digital signal and to digitally demodulate the digital signal to obtain an audio signal, where this first ADC is separate from an auxiliary ADC not part of the signal path.

Abstract: A system and method for controlling the dimming of a lighting element, or other electrical load, that uses a timer synchronized to the AC waveform is disclosed. The timer is set up to repeatedly count at a rate equal to twice the frequency of the AC waveform. An output from the timer logic is asserted when the timer value exceeds a predetermined value, stored in a compare register. This output is connected to the gate of a triac, which controls the passage of current from the AC power source to the electrical load. A capture register is used to determine the temporal relationship between the restart of the timer and the AC waveform. This system and method reduces the real time requirements of an associated processing unit, and improves consistency, thereby reducing flicker.

Abstract: A technique includes receiving a datum indicative of a candidate delimiter in a receiver; and processing the datum in a machine to determine whether the datum indicates a synchronization delimiter. The processing includes comparing the candidate delimiter with a reference delimiter to identify at least one error in the candidate delimiter; and basing the determination of whether the datum indicates the synchronization delimiter at least on a bit position of of each error.

Abstract: A technique includes using an emitter of an optical detector to emit a first optical signal and a receiver to acquire measurement of a second optical signal generated due to interaction of the first optical signal with a target. The technique includes scaling the acquired measurement based on a measure of optical crosstalk communication between the emitter and the receiver.

Abstract: A receiver includes a first amplifier, a first variable capacitor, and an inductance leg. The first amplifier has an input for receiving a radio frequency signal, and an output. The first variable capacitor has a first terminal coupled to the output of the first amplifier, a second terminal coupled to a power supply voltage terminal, and a control terminal for receiving a tuning signal. The inductance leg has a first terminal coupled to the output of the first amplifier, and a second terminal coupled to the power supply voltage terminal. The inductance leg includes a first inductor and has an effective resistance in series with the first inductor, wherein the effective resistance has a value related to an upper frequency threshold to be tuned by the receiver.

Abstract: An apparatus includes a microelectromechanical system (MEMS) device configured as part of an oscillator. The MEMS device includes a mass suspended from a substrate of the MEMS, a first electrode configured to provide a first signal based on a displacement of the mass, and a second electrode configured to receive a second signal based on the first signal. The apparatus includes an amplifier coupled to the first electrode and a first node. The amplifier is configured to generate an output signal, the output signal being based on the first signal and a first gain. The apparatus includes an attenuator configured to attenuate the output signal based on a second gain and provide as the second signal an attenuated version of the output signal.

Abstract: An integrated receiver includes a first signal processing path, a second signal processing path, and a controller. The first signal processing path has an input and an output for providing a first processed signal, and comprises a first tracking bandpass filter having a first integrated inductor formed with windings in a first number of metal layers of the integrated receiver. The second signal processing path has an input and an output for providing a second processed signal, and comprises a second tracking bandpass filter having a second integrated inductor formed with windings in a second number of metal layers of the integrated receiver. The second number of windings is lower than the first number. The controller enables one of the first and second signal processing paths corresponding to a selected channel of a radio frequency (RF) input signal to provide an output signal.

Abstract: A method and apparatus is disclosed in which delay is applied to analog-sourced audio in a radio simulcast when the analog signal initially leads the digital signal. A radio receiver is configured to receive a simulcast radio program broadcast with an analog signal and a digital signal. The program content can be extracted from either the analog or digital signals, with the audio source eventually being blended to the digital signal. Audio is initially provided based on the analog signal. If the analog signal is initially leading the digital signal, delay is applied a data stream corresponding to the analog signal relative to a data stream corresponding to the digital signal. Delay applied to the data stream corresponding to the analog signal is increased at a rate that avoids audio artifacts of the output audio. The blend is performed when the data streams are aligned in time.

Abstract: An isolation receiver includes at least one isolation capacitor to provide a first logic signal in response to a second logic signal that is provided by a transmitter. The receiver includes a signal processing circuit to amplify the first logic signal to generate an amplified signal, and the signal processing circuit includes a an amplifier to apply a nonlinear function. A comparator of the receiver provides a third logic signal in response to the amplified signal.

Abstract: A controlled oscillator is tuned to produce a desired, temperature independent frequency. A first frequency ratio is determined between a first frequency of the output signal generated by the controlled oscillator and a frequency of an output signal from another oscillator. The first frequency is determined based on a sensed temperature. A desired frequency of the output signal of the controlled oscillator is used to determine a desired frequency ratio between the desired frequency and the frequency of the output signal from the other oscillator. The controlled oscillator is tuned and the frequency ratio measured until the tuning has caused the desired frequency ratio to be achieved, thereby causing the controlled oscillator to provide the desired frequency.

Abstract: An analog signal is transported across an isolation channel using edge modulation/demodulation of a pulse width modulated (PWM) signal. An edge modulator is responsive to rising edges of the PWM signal to generate first pulses having a first predetermined pulse width and is responsive to receipt of falling edges of the PWM signal to generate second pulses having a second predetermined pulse width with the same polarity as the first pulses. On the opposite side of the isolation channel an edge demodulating circuit recreates the PWM signal using the first and second pulses. The rise and falling edges of the PWM signals can be distinguished based on the pulse width of the first and second pulses. A second order pulse width modulator may be used to generate the PWM signal.