Dual Frequency Adjustment for Physical Quantity Detection Circuits
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Solution Overview
Problem
Existing circuit devices for physical quantity detection, such as gyro sensors, face performance deterioration due to the influence of drive frequency components from physical quantity transducers on detection circuits operating with clock signals, limiting high-speed operations and detection accuracy.
Innovation Solution
A circuit device with a clock signal generation circuit that includes first and second frequency adjustment units to adjust the oscillation frequency before and after connection with the physical quantity transducer, using a CR oscillation circuit and variable resistance and capacitance circuits to minimize interference and optimize detection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a clock signal generation circuit with high oscillation frequency is used to enable high-speed operations in detection circuits, then the operating speed of detection circuits is improved, but the drive frequency component from the physical quantity transducer interferes with the clock signal, causing detection performance to deteriorate
Solution Approach 1:
The patent applies parameter changes by adjusting the oscillation frequency of the clock signal generation circuit to a value that is not an integer multiple of the drive frequency of the physical quantity transducer. This frequency parameter adjustment eliminates the interference relationship between the drive signal and clock signal, allowing high-speed operation while maintaining detection performance. The frequency is set within a specific range (0.95 to 1.05 times the drive frequency) to avoid harmonic interference.
2Measurement precision
If the oscillation frequency is adjusted after connecting the physical quantity transducer to the circuit device, then detection performance deterioration is reduced, but additional frequency adjustment steps and control mechanisms are required
Solution Approach 1:
The patent applies preliminary action by pre-setting the oscillation frequency to an appropriate value before connecting the physical quantity transducer. This preliminary frequency configuration ensures that when the transducer is connected and starts operating, the clock signal is already at a frequency that avoids interference with the drive signal, preventing detection performance deterioration from the outset.
Solution Approach 2:
The patent implements feedback by monitoring the drive frequency of the physical quantity transducer and automatically adjusting the oscillation frequency of the clock signal generation circuit accordingly. The control unit detects the drive frequency and modifies the clock signal frequency to maintain a non-integer multiple relationship, eliminating interference while maintaining optimal detection performance.
3Ease of manufacture
If the oscillation frequency is set to a value that is an integer multiple of the drive frequency, then the clock signal generation is simplified, but interference occurs between the drive signal and detection circuit, leading to performance deterioration
Solution Approach 1:
The patent applies preliminary anti-action by deliberately setting the oscillation frequency to a value that is NOT an integer multiple of the drive frequency. This counterintuitive approach prevents the harmful interference that would normally occur with integer multiple frequencies. By choosing a frequency within the specific range (0.95 to 1.05 times the drive frequency), the patent avoids harmonic interference while maintaining ease of generation through a controlled frequency relationship.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces detection performance deterioration by fine-tuning the oscillation frequency, enabling high-speed operations and improved accuracy in physical quantity detection, even when connected to physical quantity transducers.
Implementation Method 1
a CR oscillation circuit, and the first frequency adjustment unit may be a variable resistance circuit of the CR oscillation circuit
Data Source
AI summary
A circuit device includes a clock signal generation circuit that generates a clock signal through an oscillation circuit, and a detection circuit including a circuit operating through an operation signal based on the clock signal. The clock signal generation circuit includes a first frequency adjustment unit which is capable of adjusting an oscillation frequency before an physical quantity transducer and the circuit device are connected to each other, and a second frequency adjustment unit which is capable of adjusting the oscillation frequency in a state where the physical quantity transducer and the circuit device are connected to each other.