Differential Gyro Sensor Detection Circuit for Low-Noise Sampling
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Solution Overview
Problem
Existing gyro sensor detection devices face issues with large circuit scale and high power consumption, as well as insufficient noise removal due to single-end signal processing and the absence of anti-aliasing filters in direct sampling types.
Innovation Solution
A detection device with a driving circuit and a detection circuit that processes differential signals through voltage output circuits, gain adjustment amplifiers, a switching mixer, and filters, performing synchronous detection and A/D conversion to reduce noise and circuit scale, utilizing high-pass filters and passive filters to minimize 1/f noise and aliasing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an analog synchronization detection type detection device is used, then detection accuracy is improved, but circuit scale becomes large and power consumption is considerable
Solution Approach 1:
The patent replaces the analog synchronization detection circuit with a direct sampling type detection circuit that uses digital signal processing. The switching mixer samples the differential signals directly at the vibration frequency, and digital filtering subsequently removes noise, eliminating the need for complex analog synchronization detection circuits while maintaining detection accuracy.
Solution Approach 2:
The patent changes the detection approach from analog synchronous detection to direct digital sampling. By sampling the differential signals directly at the vibration frequency and using digital filtering, the system achieves the same detection accuracy with significantly reduced circuit scale and power consumption.
2Device complexity
If a direct sampling type detection device is used, then circuit scale is reduced, but aliasing noise causes performance deterioration
Solution Approach 1:
The patent applies preliminary anti-aliasing filtering by using the switching mixer to sample only the differential signals at the vibration frequency, effectively pre-filtering out high-frequency components before A/D conversion. This preliminary action prevents aliasing noise from degrading detection performance while maintaining a simple circuit scale.
3Device complexity
If single-end signal processing is used, then circuit scale is reduced, but noise removal is insufficient
Solution Approach 1:
The patent uses asymmetric differential signal processing where the first and second detection signals are processed separately through dedicated voltage output circuits and gain adjustment amplifiers, then combined in the switching mixer. This asymmetric processing of differential signals effectively removes common-mode noise while maintaining a compact circuit scale.
4Measurement precision
If differential signal processing is performed, then noise removal capability is improved, but circuit scale increases
Solution Approach 1:
The patent merges the differential signal processing functions into a single switching mixer that simultaneously samples both the first and second detection signals. By combining the voltage output circuits, gain adjustment amplifiers, and synchronous detection in an integrated manner, the system achieves effective noise removal through differential processing while suppressing circuit scale increase.
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 enables low-noise detection while reducing circuit complexity and power consumption, improving the signal-to-noise ratio by processing differential signals and utilizing frequency conversion and filter characteristics to remove noise effectively.
Implementation Method 1
a switching mixer that has a first input node to which the output signal of the first gain adjustment amplifier is input and a second input node to which the output signal of the second gain adjustment amplifier is input, performs synchronous detection on the output signal of the first gain adjustment amplifier and the output signal of the second gain adjustment amplifier on the basis of a synchronization signal from the driving circuit
Implementation Method 2
a first filter to which the first output signal from the first output node of the switching mixer is input; a second filter to which the second output signal from the second output node of the switching mixer is input
Data Source
AI summary
A detection device includes a driving circuit and a detection circuit. The detection circuit includes first and second electric charge-voltage conversion circuits to which first and second detection signals are input, first and second gain adjustment amplifiers that amplify output signals of the circuits, a switching mixer that has first and second input nodes to which the output signals of the first and second gain adjustment amplifiers are input, and performs differential synchronous detection thereon on the basis of a synchronization signal from the driving circuit, so as to output first and second output signals to first and second output nodes, first and second filters that receive the first and second output signals from the first and second output nodes of the switching mixer, and an A/D conversion circuit that receives output signals from the first and second filters so as to perform differential A/D conversion thereon.