Delta-Sigma Modulator Feedback DAC Temperature Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional temperature sensing in integrated circuits requires multiple components, increasing size, cost, and complexity, and introducing noise and error sources, which hinders the miniaturization of electronic devices like mobile phones and media players.
Innovation Solution
Integrating temperature sensing elements into a delta-sigma modulator's feedback digital-to-analog converter (DAC) reduces the number of components and eliminates the need for differential sampling and reference voltages, simplifying the circuit and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional temperature sensing modules with multiple transistors and current sources are used, then temperature sensing function is achieved, but device size and manufacturing cost increase
Solution Approach 1:
The patent merges the temperature sensing function with the feedback DAC of the delta-sigma modulator by integrating temperature sensing elements directly into the feedback path. This integration eliminates the need for separate temperature sensing modules and reduces the overall component count while maintaining accurate temperature sensing capability.
Solution Approach 2:
The feedback DAC is designed to serve dual purposes: its primary function for audio signal conversion and an additional temperature sensing function. By making the feedback DAC universal, the patent eliminates the need for dedicated temperature sensing hardware, thereby reducing device complexity without sacrificing sensing reliability.
2Measurement precision
If differential sampling with multiple switches and capacitors is used, then accurate temperature information is obtained, but device size and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the need for differential sampling circuitry by using a single-ended temperature sensing approach integrated into the feedback DAC. This extraction removes the complex network of switches and capacitors required for differential sampling while maintaining sufficient measurement precision through the integrated sensing elements.
3Reliability
If separate temperature sensing module coupled to ADC is used, then temperature sensing is achieved, but device size increases
Solution Approach 1:
The patent combines the temperature sensing module with the feedback DAC integration, eliminating the need for a separate sensing module. This merging directly reduces the occupied area on the semiconductor die while maintaining the temperature sensing capability through the integrated sensing elements within the feedback path.
4Reliability
If multiple transistors and current sources are duplicated, then temperature sensing function is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple functions into the feedback DAC structure, eliminating the need for duplicated transistors and current sources. This integration reduces the number of components that require precise matching and manual adjustment, thereby simplifying the manufacturing process and reducing costs while maintaining sensing reliability.
Solution Approach 2:
By making the feedback DAC universal for both audio conversion and temperature sensing, the patent eliminates the need for separate dedicated temperature sensing components. This multi-functionality reduces the overall component count and simplifies manufacturing without sacrificing the temperature sensing function.
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 integration reduces the size and complexity of temperature sensors, lowers manufacturing costs, and enhances accuracy by minimizing noise and error contributions, leading to more reliable temperature sensing in integrated circuits.
Implementation Method 1
The PTAT current sources 112 and 116 generate different current at different temperatures, thus the temperature may be sensed by measuring the currents
Implementation Method 2
The ADC module 120 may receive VBE1 and VBE2 inputs corresponding to voltages across the base and emitter nodes of the transistors 118 and 114, respectively
Data Source
AI summary
A delta-sigma modulator may be used to generate temperature information within an integrated circuit. The delta-sigma modulator may include a loop filter, a quantizer, and a feedback digital-to-analog converter (DAC). Temperature sensing elements may be incorporated into the feedback DAC of the delta-sigma modulator. Temperature information is then processed in the loop filter of the delta-sigma modulator and output in an average voltage value of a digital signal output from the delta-sigma modulator.