Semiconductor Temperature Sensing Without Trimming Errors
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Solution Overview
Problem
Conventional semiconductor devices require trimming techniques to achieve accurate temperature measurement, which can be costly and complex, and there is a need for a method to improve temperature measurement accuracy without these techniques.
Innovation Solution
A semiconductor device is designed with multiple current generation circuits, a voltage-current conversion circuit, and an arithmetic circuit that applies specific currents to a diode-connected transistor with a parasitic resistor, allowing for the calculation of a voltage proportional to absolute temperature, thereby eliminating the influence of the resistor's resistance value without trimming techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If trimming techniques are applied to improve temperature measurement accuracy, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the harmful influence of the parasitic resistor from the temperature measurement equation by using a differential measurement approach. By measuring voltages at two different currents and subtracting them, the parasitic resistor term is removed, leaving only the temperature-dependent term. This achieves high accuracy without requiring trimming of the parasitic resistor.
Solution Approach 2:
The patent changes the measurement parameters by using two different current values (I1 and I2) instead of a single current. This allows the formation of a differential equation that eliminates the parasitic resistor influence. The arithmetic circuit then processes these two voltage measurements to derive the temperature signal free from parasitic effects.
2Measurement precision
If trimming techniques are used to achieve accurate temperature measurement, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts and eliminates the harmful influence of the parasitic resistor from the temperature measurement equation by using a differential measurement approach. By measuring voltages at two different currents and subtracting them, the parasitic resistor term is removed, leaving only the temperature-dependent term. This achieves high accuracy without requiring trimming of the parasitic resistor.
Solution Approach 2:
The patent uses a simple arithmetic circuit with basic components (current sources, voltage measurement, and subtraction) to achieve high accuracy temperature measurement without expensive trimming processes. The solution replaces complex trimming procedures with a straightforward computational approach that is cheaper and easier to manufacture.
3Device complexity
If conventional measurement methods are used, then device complexity is low, but measurement precision deteriorates due to parasitic resistor influence
Solution Approach 1:
The patent introduces an intermediary arithmetic circuit that processes the voltage measurements from the diode-connected transistor. This intermediary circuit performs the differential calculation to eliminate parasitic resistor effects, acting as a mediator between the simple voltage measurement and the accurate temperature signal. The approach maintains circuit simplicity while achieving high precision through computational processing.
4Device complexity
If single current measurement is used, then device complexity is low, but measurement precision is reduced due to parasitic resistor effects
Solution Approach 1:
The patent changes the measurement parameters by using two different current values (I1 and I2) instead of a single current. This allows the formation of a differential equation that eliminates the parasitic resistor influence. The arithmetic circuit then processes these two voltage measurements to derive the temperature signal free from parasitic effects.
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
This approach enables highly accurate temperature measurement as a digital signal, improving accuracy beyond conventional methods without the need for trimming techniques, by isolating the temperature signal from parasitic resistor effects.
Implementation Method 1
a diode-connected transistor 11, and an arithmetic circuit 28. The arithmetic circuit 28 includes a voltage-current conversion circuit 24, a fourth current generation circuit 25, a resistor 14, and an integration circuit 26
Data Source
AI summary
The semiconductor device includes a first current generation circuit configured to generate a first current, a second current generation circuit configured to generate a second current from the first current, a third current generation circuit configured to generate a third current from the second current, a voltage-current conversion circuit configured to apply the third current to a diode and convert a generated voltage into a fourth current, a fourth current generation circuit configured to generate a fifth current from the fourth current, and an arithmetic circuit configured to generate a temperature signal from the fifth current.