Capacitance Sensor Circuit for Non-Volatile Memory Voltage Control
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Solution Overview
Problem
The existing IC tags with temperature-sensing capabilities using wax as a dielectric in capacitors face challenges in accurately controlling the rewrite voltage of non-volatile memory due to the inability to calculate the capacitance value of the film thickness, leading to inefficient data rewriting.
Innovation Solution
A semiconductor device with a capacitance sensor circuit that includes a reference capacitance unit, a determination capacitance unit, and a calibration circuit, allowing for the determination of the capacitance value of the film thickness to control the rewrite voltage of the non-volatile memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the IC tag uses a capacitor with wax dielectric to detect temperature changes, then the temperature sensing function is achieved, but the ability to calculate the capacitance value of the film thickness for controlling rewrite voltage is lost
Solution Approach 1:
The capacitor is divided into two distinct parts: a sensor capacitor using wax dielectric for temperature sensing, and a memory capacitor using film thickness for capacitance value calculation. This segmentation allows each capacitor to serve its specific function without interference, resolving the contradiction between temperature sensing and capacitance measurement capabilities
Solution Approach 2:
A calibration circuit is introduced as an intermediary component that measures the actual capacitance value of the memory capacitor and uses this information to determine the appropriate rewrite voltage. This intermediary mechanism enables accurate capacitance value calculation and rewrite voltage control while preserving the temperature sensing function of the sensor capacitor
2Device complexity
If the rewrite voltage is not controlled according to the film thickness capacitance, then the circuit operation is simpler, but the data rewriting efficiency and reliability deteriorates
Solution Approach 1:
The calibration circuit automatically measures the capacitance value and determines the appropriate rewrite voltage without requiring external intervention or complex manual calibration procedures. This self-service mechanism maintains operational simplicity while ensuring optimal rewrite voltage selection for efficient data rewriting
Solution Approach 2:
The rewrite voltage parameter is dynamically adjusted based on the measured capacitance value of the memory capacitor. By changing the voltage parameter according to the actual film thickness characteristics, the system achieves efficient data rewriting while maintaining simple circuit operation through automated parameter selection
3Measurement precision
If the capacitance sensor circuit adds reference capacitance unit and determination circuit, then the capacitance measurement capability is improved, but the device complexity increases
Solution Approach 1:
The calibration circuit combines multiple functions including reference capacitance storage, capacitance value measurement, and rewrite voltage determination into a single integrated circuit block. This merging approach improves capacitance measurement capability while minimizing the increase in overall device complexity by consolidating related functions
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
Enables precise control of the rewrite voltage based on the capacitance determined by the film thickness, improving the reliability and efficiency of data storage in non-volatile memory.
Implementation Method 1
a determination circuit that is configured to charge a capacitance of the reference capacitance unit by transmitting a charge current to the first line, to charge a capacitance of the determination capacitance unit by transmitting a charge current to the second line, and to attain a comparison result by comparing a potential of the first line to a potential of the second line
Implementation Method 2
a calibration circuit that is configured to supply, to the reference capacitance unit, a selection signal that is configured to selectively connect, on the basis of a signal level thereof, any of the plurality of capacitors to between the first line and the line of the prescribed potential by controlling the switch element connected to each of the plurality of capacitors to be ON or OFF
Data Source
AI summary
A semiconductor device comprises a control unit, a semiconductor memory, a reference capacitance unit, a determination capacitance unit, a calibration circuit configured to supply a selection signal to the reference capacitance unit to selectively connect capacitors to differing potentials, and a determination circuit configured to charge a capacitance of the reference capacitance unit, to charge a capacitance of the determination capacitance unit, and to attain a comparison result by comparing the differing potentials. The control unit is configured to control rewriting of the semiconductor memory on the basis of a determination result of the determination circuit.