Ring Oscillator Temperature Sensor with Low-Pass Noise Filtering
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Solution Overview
Problem
Existing temperature sensors using multi-stage ring oscillators face challenges in accurately measuring temperature due to high-frequency noise interference, which affects signal-to-noise ratio and test accuracy.
Innovation Solution
Incorporating a low-pass filter between the ring oscillator and comparator, configured with capacitors and transistors, to filter out high-frequency components from the square-wave signal, improving signal quality and accuracy by converting the filtered signal into a temperature value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a multi-stage ring oscillator is used to measure temperature, then temperature measurement can be performed, but high-frequency noise interference reduces signal-to-noise ratio and measurement accuracy
Solution Approach 1:
A low-pass filter is introduced as an intermediary component between the ring oscillator and the comparator. This filter mediates the signal transmission by allowing the useful square-wave signal to pass through while blocking high-frequency noise components, thereby improving the signal-to-noise ratio and temperature measurement accuracy without altering the fundamental oscillation mechanism
2Ease of manufacture
If the ring oscillator output signal is directly input to the comparator, then the measurement process is simple, but high-frequency components reduce signal quality and test accuracy
Solution Approach 1:
The low-pass filter serves as an intermediary stage that adds minimal complexity to the circuit while significantly improving measurement accuracy. The filter is implemented using standard RC or active filter topologies that are easy to integrate into existing CMOS processes, maintaining ease of manufacture while enhancing signal quality before comparison
3Measurement precision
If a low-pass filter is added between the ring oscillator and comparator, then signal-to-noise ratio and measurement accuracy are improved, but device complexity increases
Solution Approach 1:
The low-pass filter is applied locally only at the critical interface between the ring oscillator and comparator where noise filtering is most needed. This localized approach improves measurement accuracy without requiring system-wide complexity increases. The filter uses minimal components (resistors and capacitors) that can be easily integrated into the existing circuit layout
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 enhances the signal-to-noise ratio and test accuracy of temperature sensors by effectively removing high-frequency noise, leading to more reliable temperature measurements.
Implementation Method 1
the low-pass filter is configured to filter out a high-frequency component in the square-wave signal output from the ring oscillator
Data Source
AI summary
Provided are a temperature sensor, an array substrate, and a display device. In the temperature sensor, a low-pass filter is disposed between a ring oscillator and a comparator, so that a square-wave signal output from the ring oscillator passes through the low-pass filter and a high-frequency component in the square-wave signal output from the ring oscillator is directly filtered out by the low-pass filter, thereby improving a signal-to-noise ratio of the ring oscillator and a test accuracy of the temperature sensor.