PDM Temperature Sensor Eliminates Reference Voltage Circuit
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Solution Overview
Problem
Conventional temperature sensors that output digital signals based on temperature require a larger area and consume more power due to the use of reference voltage circuits.
Innovation Solution
A pulse density modulation (PDM) output temperature sensor design that eliminates the reference voltage circuit, utilizing constant current sources, PNP bipolar transistors, switches, capacitors, amplifiers, comparators, latches, inverters, and oscillation circuits to generate a digital signal directly from temperature-dependent voltages, reducing area and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reference voltage circuit is used in a temperature sensor, then the temperature measurement accuracy is maintained, but the sensor area and power consumption increase
Solution Approach 1:
The patent extracts and removes the reference voltage circuit from the temperature sensor structure. By eliminating this separate circuit block, the sensor area is reduced while the temperature measurement function is maintained through direct comparison of temperature-dependent voltages generated by the sensor elements themselves.
Solution Approach 2:
The patent merges the reference voltage generation function into the temperature sensing elements themselves. The temperature-dependent voltage sources serve dual purposes: generating the measurement signal and providing the reference for comparison, thereby eliminating the need for a separate reference voltage circuit.
2Measurement precision
If a reference voltage circuit is used in a temperature sensor, then the temperature measurement accuracy is maintained, but the power consumption increases
Solution Approach 1:
The patent extracts and removes the reference voltage circuit from the temperature sensor structure. By eliminating this separate circuit block, power consumption is reduced while the temperature measurement function is maintained through direct comparison of temperature-dependent voltages generated by the sensor elements themselves.
Solution Approach 2:
The temperature sensing elements generate their own reference voltages through self-heating or inherent temperature dependence. This self-service mechanism eliminates the need for external power-intensive reference voltage generation circuits, thereby reducing overall power consumption while maintaining measurement accuracy.
3Measurement precision
If a conventional temperature sensor structure is used, then accurate temperature measurement is achieved, but the circuit complexity and number of components increase
Solution Approach 1:
The patent extracts and removes the reference voltage circuit from the conventional temperature sensor structure. This elimination simplifies the overall circuit architecture by reducing the number of separate functional blocks and interconnections required.
Solution Approach 2:
The patent merges multiple functions into the temperature sensing elements themselves. The sensing elements simultaneously provide temperature-dependent voltage generation and reference voltage provision, thereby reducing the total number of circuit components and simplifying the overall device structure.
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 PDM output temperature sensor achieves a smaller footprint and lower power consumption while maintaining accurate temperature signal output, simplifying circuit design and reducing switching noise and precision requirements.
Implementation Method 1
a first PNP bipolar transistor having a base and a collector connected to a ground terminal, and an emitter connected to the first node; a second PNP bipolar transistor having a base and a collector connected to the ground terminal, and an emitter connected to the fourth node
Data Source
AI summary
To provide a PDM output temperature sensor, which is reduced in area and consumption power, provided is a PDM output temperature sensor which includes no reference voltage circuit, thereby having a smaller area and consuming less power correspondingly.