Bandgap Reference Circuit With Multi-Slope Current Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bandgap reference voltage generation circuits face challenges in achieving high precision and robustness against process variations, leading to significant temperature drift and batch differences.
Innovation Solution
A bandgap reference voltage generation circuit with a multi-segment compensation mechanism, incorporating bipolar junction transistors with different current densities, feedback circuits, and a calibration control system to generate a compensation current with multiple temperature slopes, reducing temperature coefficient variations through superimposed current segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If low-order temperature compensation is used with resistors, then the circuit structure is simple, but the temperature coefficient variation is significant and precision is poor
Solution Approach 1:
The compensation current is divided into multiple segments with different temperature coefficients. Each segment is generated by separate current sources that are activated at different temperature ranges, allowing precise compensation across the entire temperature spectrum while maintaining circuit simplicity
Solution Approach 2:
The patent changes the temperature coefficient parameters by using multiple current sources with different temperature characteristics. By adjusting the activation temperatures and coefficient values of each current segment, the overall temperature compensation precision is improved without significantly increasing circuit complexity
2Reliability
If process variations are considered, then the bandgap reference voltage drifts significantly with temperature and batch differences, but adding complex compensation circuits increases device complexity
Solution Approach 1:
The patent implements dynamic temperature compensation by using multiple current segments that are selectively activated based on temperature conditions. This dynamic approach allows the compensation circuit to adapt to different temperature ranges and process variations without requiring a fully complex static circuit design
Solution Approach 2:
The patent uses feedback mechanisms to detect temperature changes and adjust the compensation current segments accordingly. This feedback-based approach improves reliability against process variations while keeping the circuit complexity manageable through intelligent control
3Measurement precision
If high-order temperature compensation is implemented with multiple current segments, then temperature coefficient variation is reduced and precision is improved, but the circuit complexity increases
Solution Approach 1:
The compensation function is segmented into multiple independent current sources, each responsible for a specific temperature range. This segmentation allows high-order temperature compensation to be achieved through modular design, reducing the overall circuit complexity compared to a monolithic high-order compensation circuit
Solution Approach 2:
The patent applies partial compensation action by activating only the necessary current segments for each temperature range. This approach achieves high precision where needed while avoiding the complexity of full high-order compensation across all temperature conditions
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 circuit achieves high-order temperature compensation, significantly reducing temperature coefficient variations and ensuring precision across different process batches.
Implementation Method 1
bipolar junction transistors Q1 and Q2 are transistors with different current densities or area ratios, used to generate a positive temperature coefficient current and a negative temperature coefficient current
Implementation Method 2
An amplifier detects a voltage difference across the bipolar junction transistors Q1 and Q2 and enforces this voltage difference across a delta-voltage sensing resistor R1, thereby forming a positive temperature coefficient current
Implementation Method 3
the first positive temperature coefficient current and the first negative temperature coefficient current are superimposed to form an output current exhibiting a low-order temperature compensation characteristic
Data Source
AI summary
A bandgap reference voltage generation circuit includes two bipolar junction transistors biased at different current densities to generate a base-emitter voltage difference, and to determine a negative temperature coefficient current. The circuit further includes a delta-voltage sensing resistor and a feedback circuit to ensure that the voltage drop across the delta-voltage sensing resistor includes the voltage difference, thereby generating a positive temperature coefficient current. The positive and negative temperature coefficient currents are combined to bias an output resistor, generating an output current with low-order temperature compensation. A multi-stage compensation circuit further generates a compensation current, which is injected into a tap of the output resistor to form a bandgap reference voltage with high-order temperature compensation. The compensation current varies with temperature and exhibits at least three stages of temperature coefficient.