摘要:
An angular velocity sensor including a vibration body having a sensor electrode, a driving electrode, and a monitor electrode. The monitor electrode generates a signal according to vibration of the vibration body. The sensor circuit outputs a signal representing an angular velocity applied to the vibration body. The amplitude determination circuit measures amplitude of vibration of the vibration body. A PLL circuit includes a constant voltage source for generating a constant voltage, a timing switching unit for outputting a voltage by switching selectively between the constant voltage and a voltage corresponding to the monitor signal, and a voltage-controlled oscillator for outputting an oscillation signal having a frequency corresponding to the voltage output from the timing switching unit. When the amplitude measured is smaller than a predetermined value, the timing switching unit outputs the constant voltage output from the constant voltage source and outputs a start-up mode signal.
摘要:
An angular velocity sensor includes a vibration body having a sensor electrode, a driving electrode, and a monitor electrode. The monitor electrode generates a signal according to vibration of the vibration body. The sensor circuit outputs a signal representing an angular velocity applied to the vibration body. The amplitude determination circuit measures amplitude of vibration of the vibration body. A PLL circuit includes a constant voltage source for generating a constant voltage, a timing switching unit for outputting a voltage by switching selectively between the constant voltage and a voltage corresponding to the monitor signal, and a voltage-controlled oscillator for outputting an oscillation signal having a frequency corresponding to the voltage output from the timing switching unit. When the amplitude measured by the amplitude determination circuit is smaller than a predetermined value, the timing switching unit outputs, to the voltage-controlled oscillator, the constant voltage output from the constant voltage source and outputs a start-up mode signal. This angular velocity sensor has a stable output characteristic.
摘要:
An angular velocity sensor includes a vibration, first and second sensor electrodes generating an electric charge responsive to an angular velocity applied to the vibration body, first and D/A converters each outputting at least two levels of an electric charge, first and second integrator circuits integrating the electric charge generated by the first and second sensor electrodes and the electric charges output from the first and second D/A converters, respectively, a comparator unit comparing output signals from the first and second integrator circuits, first and second D/A switching units switching levels of the output signals from the first and second D/A converters according to a comparison result of the comparator unit, a first disconnection detecting switch connected between the first sensor electrode and the first integrator circuit, a first voltage source for injecting an electric charge into a point between the first sensor electrode and the first integrator circuit via the first disconnection detecting switch, a second disconnection detecting switch connected between the second sensor electrode and the second integrator circuit, and a second voltage source for injecting an electric charge into a point between the second sensor electrode and the second integrator circuit via the second disconnection detecting switch. This angular velocity sensor has a high reliability and performs stable operation even if ambient environment changes.
摘要:
An angular velocity sensor has a stable output characteristic using a sigma-delta type analog-to-digital converter. The sigma-delta type analog-to-digital converter includes an integrator unit for integrating electric charges output from an input switching device and a digital-to-analog converter unit, and holding at least two integrated values, a comparator unit for comparing at least the two integrated values output from the integrator unit with a predetermined value. The sigma-delta-type analog-to-digital converter also includes an arithmetic operation unit for operating an output signal of the comparator unit, the arithmetic operation unit being provided with a differential operation unit for computing a difference between at least two comparison signals output from comparator unit.
摘要:
A PLL circuit is provided with an AD converter, a DA converter to which output from the AD converter is inputted, a filter circuit filtering an output signal of the DA converter, a voltage control oscillator outputting a signal of a different frequency in accordance with an output signal from the filter circuit and a frequency divider dividing a signal which the voltage control oscillator outputs. The AD converter operates by a timing signal from the voltage control oscillator and the DA converter outputs an analog signal corresponding to a value which the AD converter outputs by the timing signal outputted from the frequency divider.
摘要:
An angular velocity sensor includes a vibration body, first and second sensor electrodes generating an electric charge responsive to an angular velocity applied to the vibration body, first and D/A converters each outputting at least two levels of an electric charge, first and second integrator circuits integrating the electric charge generated by the first and second sensor electrodes and the electric charges output from the first and second D/A converters, respectively, a comparator unit comparing output signals from the first and second integrator circuits, first and second D/A switching units switching levels of the output signals from the first and second D/A converters according to a comparison result of the comparator unit, a first disconnection detecting switch connected between the first sensor electrode and the first integrator circuit, a first voltage source for injecting an electric charge into a point between the first sensor electrode and the first integrator circuit via the first disconnection detecting switch, a second disconnection detecting switch connected between the second sensor electrode and the second integrator circuit, and a second voltage source for injecting an electric charge into a point between the second sensor electrode and the second integrator circuit via the second disconnection detecting switch. This angular velocity sensor has a high reliability and performs stable operation even if ambient environment changes.
摘要:
The present invention particularly relates to an inertial force sensor used in various electronic equipment, for example, used for altitude control, navigation, or the like, of a mobile body such as an aircraft, an automobile, a robot, a watercraft and a vehicle in which the detection accuracy is enhanced. Therefore, a sense circuit constituting the inertial force sensor includes a sigma-delta modulator converting a sense signal output from a sense electrode into a one-bit digital signal, and a signal processing circuit (i) comparing a monitor signal output from a monitor electrode with predetermined reference amplitude information, (ii) carrying out operation processing of the one-bit digital signal based on this comparison information, and (iii) adjusting an output level of the output signal.
摘要:
An angular velocity sensor with a stable output characteristic using a sigma-delta type analog-to-digital converter comprising an integrator unit for integrating electric charges output from an input switching device and a digital-to-analog converter unit and holding at least two integrated values, a comparator unit for comparing at least the two integrated values output from the integrator unit with a predetermined value, and an arithmetic operation unit for operating an output signal of the comparator unit, the arithmetic operation unit provided with a differential operation unit for computing a difference between at least two comparison signals output from comparator unit.
摘要:
A PLL circuit is provided with an AD converter, a DA converter to which output from the AD converter is inputted, a filter circuit filtering an output signal of the DA converter, a voltage control oscillator outputting a signal of a different frequency in accordance with an output signal from the filter circuit and a frequency divider dividing a signal which the voltage control oscillator outputs. The AD converter operates by a timing signal from the voltage control oscillator and the DA converter outputs an analog signal corresponding to a value which the AD converter outputs by the timing signal outputted from the frequency divider.
摘要:
The present invention particularly relates to an inertial force sensor used in various electronic equipment, for example, used for attitude control, navigation, or the like, of a mobile body such as an aircraft, an automobile, a robot, a watercraft and a vehicle in which the detection accuracy is enhanced. Therefore, a sense circuit constituting the inertial force sensor includes a sigma-delta modulator for converting a sense signal output from a sense electrode into a one-bit digital signal, and a signal processing circuit for comparing a monitor signal output from a monitor electrode with predetermined reference amplitude information, carrying out operation processing of the one-bit digital signal based on this comparison information, and adjusting an output level of the output signal.