Abstract:
Circuits and methods for aligning two or more signals including a first and second signal. In one embodiment, a shift register generates two or more shifted copies of the second signal, and each of a plurality of phase detectors receives the first signal and one of the shifted copies of the second signal, each phase detector providing an output indicating whether the first signal is substantially aligned with the shifted copy of the second signal. A multiplexer may also be provided for receiving each of the shifted copies of the second signal, the multiplexer having a plurality of select lines coupled with the output signals of the phase detectors. Some embodiments may include a power saving mode.
Abstract:
Circuits and methods for aligning two or more signals including a first and second signal. In one embodiment, a shift register generates two or more shifted copies of the second signal, and each of a plurality of phase detectors receives the first signal and one of the shifted copies of the second signal, each phase detector providing an output indicating whether the first signal is substantially aligned with the shifted copy of the second signal. A multiplexer may also be provided for receiving each of the shifted copies of the second signal, the multiplexer having a plurality of select lines coupled with the output signals of the phase detectors. Some embodiments may include a power saving mode.
Abstract:
The present invention adds an additional feedback loop to a phase locked loop (PLL). The additional feedback loop detects if the actual output frequency of the PLL is above or below the desired output frequency. If the actual output frequency is above the desired output frequency a signal is added to the forward path of the PLL to decrease the frequency of the PLL oscillator. If the actual output frequency is below the desired output frequency a signal is added to the forward path of the PLL to increase the frequency of the PLL oscillator.
Abstract:
A circuit and method for providing a periodic clock signal, such as a high frequency clock signal. In one example, the circuit may include a phase locked loop circuit having a voltage controlled oscillator, the voltage controlled oscillator having a voltage input, a calibration input, and a clock signal output; and a logic circuit for dynamically calibrating an operating frequency of the phase locked loop during operation of the phase locked loop. In one embodiment, the logic circuit may compare an input voltage into the voltage controlled oscillator against a reference voltage, and if the input voltage is lower than the reference voltage, the logic circuit decreases the operating frequency of the phase locked loop circuit. The logic circuit may compare an input voltage into the voltage controlled oscillator against a reference voltage, and if the input voltage is higher than the reference voltage, the logic circuit increases the operating frequency of the phase locked loop circuit.
Abstract:
One embodiment includes a system configured to identify a preferred channel for radio communication from a plurality of consecutive integer frequencies including preferred channels and non-preferred channels, the system further to generate a plurality of radio channels corresponding to a plurality of consecutive integer frequencies based on a generation of reference frequencies, identifies preferred channels and non-preferred channels from the plurality of radio channels, where frequency synthesizer settling times of the preferred channels are faster than frequency synthesizer settling times of the non-preferred channels, scan the preferred channels for radio activity, select one of preferred channels responsive to the scanned radio activity; and utilize one of the reference frequencies to generate a radio frequency corresponding to the selected one of the preferred channels.
Abstract:
In a system with an intermittently operating radio, the frequency of which is controlled by a Phase Locked Loop (PLL), a method and system for reducing the power consumed by the PLL by tri-stating the control capacitor in the PLL after the PLL has stabilized at a design frequency. After the capacitor is stabilized, power to some of the components in the PLL is reduced.
Abstract:
A phase frequency detector (PFD) utilizes hysteresis dead zone avoidance while maximizing the linear range and minimizing the power and area consumed by the PFD circuit. The PFD includes a hysteresis in a reset logic gate, which prevents the reset logic gate from switching its output before each of the corrective pulses from the PFD reach final steady state DC voltage values. The PFD response simulates an ideal response, such that linearity is maintained at the phase lock point and throughout a linear range of +/−2&pgr;. In addition, the hysteresis reset logic gate monitors the corrective pulses to insert an appropriate amount of time delay into the PFD reset path without introducing additional delay elements. As a result, the linear range of the PHD is maximized and the power and area consumed by the PFD is minimized, due to the fact that additional delay elements are eliminated from the design.
Abstract:
A capacitance measurement sensor, having a voltage subtractor that rejects common signals between the columns or rows of a touch sensor matrix depending on which are driven and which are being sensed, is described.
Abstract:
A system and method for measuring capacitance of a capacitive sensor array is disclosed. Upon measuring the capacitance, position information with respect to the sensor array may be determined. A column, a first row, and a second row of a capacitive sensor array may be selected. The first row and the second row intersect with the column of the capacitive sensor array. A differential capacitance between the first row and the second row may be measured. The differential capacitance may be utilized in determining a location of an object proximate to the capacitive sensor array.
Abstract:
In a system with an intermittently operating radio, the frequency of which is controlled by a Phase Locked Loop (PLL), a method and system for reducing the power consumed by the PLL by tri-stating the control capacitor in the PLL after the PLL has stabilized at a design frequency. After the capacitor is stabilized, power to some of the components in the PLL is reduced.