Bandgap Reference Voltage Circuit Temperature Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reference voltage generating circuits face challenges in achieving low temperature dependence due to variations in process and resistance values, leading to inaccuracies in temperature correction.
Innovation Solution
A reference voltage generating circuit is designed with a bandgap reference circuit, PTAT current generating circuit, and linear approximate correction current generating circuit, which divides temperature characteristics into sections for linear approximation and adds correction voltage to reduce temperature dependence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a differential pair correction circuit is used to generate correction current based on temperature variation, then temperature dependence of reference voltage is reduced, but manufacturing precision deteriorates due to process variations affecting transconductance and resistance values
Solution Approach 1:
The patent changes the operating parameters of the correction circuit by applying temperature compensation voltages that vary according to temperature. The correction circuit adjusts its transfer characteristics dynamically based on temperature conditions, allowing the system to maintain accurate correction across different temperatures without being affected by fixed process variations in transconductance and resistance values.
Solution Approach 2:
The patent implements feedback mechanisms where the correction circuit continuously monitors temperature conditions and adjusts the correction current accordingly. The correction voltage is fed back to compensate for temperature-induced variations in the reference voltage, creating a closed-loop system that maintains precision despite manufacturing variations.
2Stability of the object's composition
If correction voltage is added to reduce temperature dependence, then temperature stability is improved, but device complexity increases due to additional correction circuits
Solution Approach 1:
The patent merges the correction circuit functionality with the existing reference voltage generation circuitry. The correction circuit is integrated into the bandgap reference structure, sharing common elements such as current sources and voltage nodes. This combination achieves temperature compensation without requiring completely separate correction circuitry, thereby limiting the increase in device complexity.
Solution Approach 2:
The correction circuit is designed to perform multiple functions: it generates correction current based on temperature, adjusts the reference voltage output, and compensates for process variations. By making the correction circuit multi-functional, the patent reduces the need for additional dedicated circuits, thus improving temperature stability while controlling device complexity.
Data Source
AI summary
A reference voltage generating circuit with extremely low temperature dependence is provided. The reference voltage generating circuit includes a BGR circuit which generates a bandgap reference voltage; a bandgap current generating circuit which generates a bandgap current according to the bandgap reference voltage; a PTAT current generating circuit which generates a current proportional to the absolute temperature; and a linear approximate correction current generating circuit which compares the current generated by the PTAT current generating circuit and the bandgap current to generate a correction current, and the BGR circuit adds, to the bandgap reference voltage, a correction voltage generated based on the correction current.