Abstract: Embodiments of the present invention provide a motor-driven mechanical system with a detection system to measure properties of a back channel and derive oscillatory characteristics of the mechanical system. Uses of the detection system may include calculating the resonant frequency of the mechanical system and a threshold drive DTH required to move the mechanical system from the starting mechanical stop position. System manufacturers often do not know the resonant frequency and DTH of their mechanical systems precisely. Therefore, the calculation of the specific mechanical system's resonant frequency and DTH rather than depending on the manufacturer's expected values improves precision in the mechanical system use. The backchannel calculations may be used either to replace or to improve corresponding pre-programmed values.

Abstract: A digital sine wave may be converted to an analog signal at a digital to analog converter (DAC). The converted analog signal may be supplied to a device and an analog return signal from the device may be passed through a relaxed anti-aliasing filter and converted to digital code words at an analog to digital converter (ADC). An impedance may be calculated from the results of a Fourier analysis of the digital code words. The ADC and DAC clock frequencies may be asynchronous, independently variable, and have a greatest common factor of 1. The clock frequencies of the ADC and/or DAC may be adjusted to change a location of images in the ADC spectrum. By using these different, adjustable clock frequencies for the ADC and the DAC, an analog signal may have increased aliasing without introducing signal errors at a frequency of interest.

Abstract: It is known to perform sample rate conversion. A sample rate converter is arranged to receive digital data at an input sample rate Fs and to output data at an output sample rate Fo, where Fo=Fs/N, and N is decimation factor greater than 1. A problem can arise with sample rate converters when a user wishes to change the decimation rate. Generally a sample rate converter needs to discard the samples in its filter when the decimation rate is changed, and the filter output is unusable until the filter has refilled with values taken at the new decimation rate. The sample rate converter provided here does not suffer from this problem. The sample rate converter includes at least Q channels.

Abstract: Techniques to provide calibration of a measurement system in conjunction with measurement operations. The techniques may include providing a reference device in a signal processing chain within the measurement system. An excitation signal may be driven through the reference device while it may be connected to the signal processing chain within the measurement system and a calibration response may be captured. During a measurement operation, the reference device connection may be complemented with a sensor connection in the signal processing chain and the excitation signal may be driven through the signal processing chain. A measurement response may be captured from the system. The measurement system may generate a calibrated measurement signal that accounts for phase and/or amplitude errors within the system from the calibration response and the measurement response.

Abstract: It is known to perform sample rate conversion. A sample rate converter is arranged to receive digital data at an input sample rate Fs and to output data at an output sample rate Fo, where Fo=Fs/N, and N is decimation factor greater than 1. A problem can arise with sample rate converters when a user wishes to change the decimation rate. Generally a sample rate converter needs to discard the samples in its filter when the decimation rate is changed, and the filter output is unusable until the filter has refilled with values taken at the new decimation rate. The sample rate converter provided here does not suffer from this problem. The sample rate converter includes at least Q channels.

Abstract: An example transconductance circuit is provided in accordance with one embodiment. The transconductance circuit can comprise: an output node; at least one transistor; a variable resistance; and a differential amplifier; wherein the at least one transistor and the variable resistance are in series connection with the output node, an output of the differential amplifier is connected to a control node of the at least one transistor, a first input of the amplifier is responsive to an input signal, and a second input of the amplifier is responsive to a voltage across the variable resistance. Such a circuit may overcome noise problems in transconductance circuits which operate over a wide range of input signals with a fixed resistor in series with the at least one transistor.

Abstract: An example transconductance circuit is provided in accordance with one embodiment. The transconductance circuit can comprise: an output node; at least one transistor; a variable resistance; and a differential amplifier; wherein the at least one transistor and the variable resistance are in series connection with the output node, an output of the differential amplifier is connected to a control node of the at least one transistor, a first input of the amplifier is responsive to an input signal, and a second input of the amplifier is responsive to a voltage across the variable resistance. Such a circuit may overcome noise problems in transconductance circuits which operate over a wide range of input signals with a fixed resistor in series with the at least one transistor.

Abstract: A drive signal for a motor-driven mechanical system has zero (or near zero) energy at an expected resonant frequency of the mechanical system. These techniques not only generate a drive signal with substantially no energy at the expected resonant frequency, they provide a zero-energy “notch” of sufficient width to tolerate systems in which the actual resonant frequency differs from the expected resonant frequencies.

Abstract: Embodiments of the present invention provide a motor-driven mechanical system with a detection system to measure properties of a back channel and derive oscillatory characteristics of the mechanical system. Uses of the detection system may include calculating the resonant frequency of the mechanical system and a threshold drive DTH required to move the mechanical system from the starting mechanical stop position. System manufacturers often do not know the resonant frequency and DTH of their mechanical systems precisely. Therefore, the calculation of the specific mechanical system's resonant frequency and DTH rather than depending on the manufacturer's expected values improves precision in the mechanical system use. The backchannel calculations may be used either to replace or to improve corresponding pre-programmed values.

Abstract: Embodiments of the present invention provide a motor-driven mechanical system with a detection system to measure properties of a back channel and derive oscillatory characteristics of the mechanical system. Uses of the detection system may include calculating the resonant frequency of the mechanical system and a threshold drive DTH required to move the mechanical system from the starting mechanical stop position. System manufacturers often do not know the resonant frequency and DTH of their mechanical systems precisely. Therefore, the calculation of the specific mechanical system's resonant frequency and DTH rather than depending on the manufacturer's expected values improves precision in the mechanical system use. The backchannel calculations may be used either to replace or to improve corresponding pre-programmed values.

Abstract: A control circuit for use with a four terminal sensor, the sensor having first and second drive terminals and first and second measurement terminals, the control circuit arranged to drive at least one of the first and second drive terminals with an excitation signal, to sense a voltage difference between the first and second measurement terminals, and control the excitation signal such that the voltage difference between the first and second measurement terminals is within a target range of voltages, and wherein the control circuit includes N poles in its transfer characteristic and N?1 zeros in its transfer characteristic such that when a loop gain falls to unity the phase shift around a closed loop is not substantially 2? radians or a multiple thereof, where N is greater than 1.

Abstract: A control circuit for use with a four terminal sensor, the sensor having first and second drive terminals and first and second measurement terminals, the control circuit arranged to drive at least one of the first and second drive terminals with an excitation signal, to sense a voltage difference between the first and second measurement terminals, and control the excitation signal such that the voltage difference between the first and second measurement terminals is within a target range of voltages, and wherein the control circuit includes N poles in its transfer characteristic and N?1 zeros in its transfer characteristic such that when a loop gain falls to unity the phase shift around a closed loop is not substantially 2? radians or a multiple thereof, where N is greater than 1.

Abstract: Embodiments of the present invention provide an integrated circuit system including a first active layer fabricated on a front side of a semiconductor die and a second pre-fabricated layer on a back side of the semiconductor die and having electrical components embodied therein, wherein the electrical components include at least one discrete passive component. The integrated circuit system also includes at least one electrical path coupling the first active layer and the second pre-fabricated layer.

Abstract: A digital sine wave may be converted to an analog signal at a digital to analog converter (DAC). The converted analog signal may be supplied to a device and an analog return signal from the device may be passed through a relaxed anti-aliasing filter and converted to digital code words at an analog to digital converter (ADC). An impedance may be calculated from the results of a Fourier analysis of the digital code words. The ADC and DAC clock frequencies may be asynchronous, independently variable, and have a greatest common factor of 1. The clock frequencies of the ADC and/or DAC may be adjusted to change a location of images in the ADC spectrum. By using these different, adjustable clock frequencies for the ADC and the DAC, an analog signal may have increased aliasing without introducing signal errors at a frequency of interest.

Abstract: A method and system that may include a pair of amplifier transistors and an output coupled to a load device. The precharge buffer may be controlled by an activation signal. The precharge buffer may also include a pair of level shifters. Each level shifter may be provided in association with a respective one of the transistors, and each may provide a respective level shift to an input signal at a common signal source based on a reference voltage. Outputs of the level shifters may be coupled to the respective transistors. The precharge buffer may also include a bypass signal path extending from the common signal source to the load device. A signal path may be controlled by another activation signal, and the precharge buffer and the bypass signal may be enabled during mutually exclusive states of the activation signal.

Abstract: An architecture of an integrated circuit allows for the canceling of noise sampled on a capacitor in the integrated circuit, after an input signal has already been sampled. Thermal noise correlated with an arbitrary input signal may be canceled after selectively controlling a plurality of switching devices during a sequence of clock phases. An auxiliary capacitor may be used to store a voltage equal to the thermal noise and enable the cancellation of the thermal noise from the sampled signal in conjunction with a noise cancellation unit.

Abstract: Techniques to provide calibration of a measurement system in conjunction with measurement operations. The techniques may include providing a reference device in a signal processing chain within the measurement system. An excitation signal may be driven through the reference device while it may be connected to the signal processing chain within the measurement system and a calibration response may be captured. During a measurement operation, the reference device connection may be complemented with a sensor connection in the signal processing chain and the excitation signal may be driven through the signal processing chain. A measurement response may be captured from the system. The measurement system may generate a calibrated measurement signal that accounts for phase and/or amplitude errors within the system from the calibration response and the measurement response.

Abstract: An architecture of an integrated circuit allows for the canceling of noise sampled on a capacitor in the integrated circuit, after an input signal has already been sampled. Thermal noise correlated with an arbitrary input signal may be canceled after selectively controlling a plurality of switching devices during a sequence of clock phases. An auxiliary capacitor may be used to store a voltage equal to the thermal noise and enable the cancellation of the thermal noise from the sampled signal in conjunction with a noise cancellation unit.

Abstract: Embodiments of the present invention provide a drive signal for a motor-driven mechanical system whose frequency distribution has zero (or near zero) energy at the expected resonant frequency of the mechanical system. The drive signal may be provided as a pair of steps sufficient to activate movement of the mechanical system and then park the mechanical system at a destination position. The steps are spaced in time so as to have substantially zero energy at an expected resonant frequency fR of the mechanical system. The drive signal may be filtered to broaden a zero-energy notch at the expected resonant frequency fR.

Abstract: A drive signal for a motor-driven mechanical system has zero (or near zero) energy at an expected resonant frequency of the mechanical system. These techniques not only generate a drive signal with substantially no energy at the expected resonant frequency, they provide a zero-energy “notch” of sufficient width to tolerate systems in which the actual resonant frequency differs from the expected resonant frequencies.