Temperature Detection Circuit with Variable Voltage Dividing Resistors
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Solution Overview
Problem
Existing temperature detection circuits for semiconductor integrated devices face challenges in achieving accurate temperature detection due to manufacturing variations in components like thermistors and bandgap reference circuits, leading to reduced accuracy and sensitivity.
Innovation Solution
A temperature detection circuit utilizing first and second diodes with independent p-n junctions, variable voltage dividing resistors, and a reference voltage generation part to produce a temperature-independent reference voltage and temperature detection signal, with adjustable resistance ratios and amplification gain to compensate for manufacturing variations and set sensitivity arbitrarily.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a thermistor is used to detect temperature, then temperature detection is enabled, but manufacturing variations cause reduced accuracy
Solution Approach 1:
The patent uses a bandgap reference circuit to generate a temperature-independent reference voltage that serves as a stable baseline for temperature detection. This reference voltage is copied from fundamental physical constants (bandgap voltage) rather than from a temperature-sensitive component, thereby eliminating the manufacturing variation problem inherent in thermistors. The reference voltage is used to calibrate and compensate for variations in the temperature detection path.
2Measurement precision
If a bandgap reference circuit is used to generate temperature-independent reference voltage, then temperature detection is enabled, but component manufacturing variations reduce accuracy
Solution Approach 1:
The patent employs feedback mechanisms where the generated reference voltage is fed back to adjust and compensate for manufacturing variations in the detection path. The circuit continuously monitors the reference voltage and uses this information to correct for deviations caused by component variations, thereby maintaining high measurement precision despite manufacturing tolerances.
Solution Approach 2:
The patent changes the operating parameters of the bandgap reference circuit to optimize performance. By adjusting the current ratios, resistor ratios, and transistor biasing conditions, the circuit achieves better immunity to manufacturing variations. The design carefully selects operating points where the temperature coefficient is minimized and the sensitivity to process variations is reduced.
3Adaptability or versatility
If variable voltage dividing resistors are used to adjust resistance ratios, then sensitivity can be set arbitrarily, but device complexity increases
Solution Approach 1:
The patent introduces variable voltage dividing resistors that can dynamically adjust their resistance ratios to optimize sensitivity for different operating conditions. These variable resistors allow the circuit to adapt its gain and scaling factors based on the specific application requirements, enabling arbitrary sensitivity settings while maintaining a relatively compact implementation through shared circuitry.
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 high-accuracy temperature detection while minimizing the impact of manufacturing variations, allowing for precise temperature monitoring and reduced adjustment time under the same temperature conditions.
Implementation Method 1
first and second diodes having respective p-n junctions independent from each other
Data Source
AI summary
A temperature detection circuit that can detect temperature with high accuracy regardless of manufacturing variations, and a method of adjusting the same. The circuit includes: first and second diodes having respective independent p-n junctions; a first current path including a first variable voltage dividing resistor series connected to the first diode; a second current path including a second variable voltage dividing resistor series connected to the second diode; a reference voltage generation part that feeds back a differential voltage to each of the first and second current paths and outputs as a reference voltage the differential voltage indicating a difference between a first divided voltage of the first variable voltage dividing resistor and a potential on the second current path; and a temperature detection signal generation part generating a temperature detection signal based on a second divided voltage of the second variable voltage dividing resistor.