Reference Voltage Generator Circuit with Mirror Current Source
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Solution Overview
Problem
Conventional reference voltage generator circuits in high-voltage ICs face challenges in generating high-accuracy reference voltages due to variations in current and resistor values at different process corners and temperatures.
Innovation Solution
A reference voltage generator circuit with a mirror constant current source having two branches, where the first branch contains a resistive element and the second branch has two resistive elements in series, with transistors and diodes configured to maintain proportional currents and adjust the resistance ratio to achieve high-accuracy reference voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional reference voltage generator circuits use in-series resistors to generate reference voltage, then the circuit structure is simple, but the reference voltage accuracy deteriorates due to current and resistor value variations at different process corners and temperatures
Solution Approach 1:
The circuit is divided into two separate branches: a first branch containing a first resistor and a second branch containing a second resistor. This segmentation allows independent optimization of each branch's function, with the first branch generating a stable reference voltage and the second branch providing current mirroring to compensate for process and temperature variations.
Solution Approach 2:
A current mirror circuit is introduced as an intermediary mechanism between the reference voltage generation and the output. The current mirror copies the reference current from the first branch to the second branch, ensuring that the current through the second resistor remains stable despite variations in process corners and temperatures, thereby improving reference voltage accuracy.
2Measurement precision
If a mirror constant current source with two branches and proportional currents is used, then reference voltage accuracy is improved, but the device complexity increases
Solution Approach 1:
The current mirror circuit copies the current from the first branch to the second branch with a defined proportion M:N. This copying mechanism ensures that the current through the second resistor is proportional to the stable reference current, thereby generating an accurate reference voltage at the power supply terminal while using standard resistor values.
Solution Approach 2:
The invention changes the current parameter by introducing a proportional relationship (M:N) between the currents in the two branches. By adjusting the proportion M:N and the resistor ratio, the reference voltage can be precisely controlled. This parameter change allows flexibility in generating different reference voltage levels while maintaining high accuracy.
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 configuration allows for the generation of high-accuracy reference voltages at the power supply terminal, which is flexible and important for high-voltage ICs, reducing the impact of environmental and process variations.
Implementation Method 1
a mirror constant current source having a first branch and a second branch, wherein a first current on the first branch is proportional to a second current on the second branch
Data Source
AI summary
Various embodiments of the present invention relate to a reference voltage generator circuit. Specifically, the circuit may for example comprise: a mirror constant current source having a first branch and a second branch, wherein a first current on the first branch is proportional to a second current on the second branch; wherein the first branch has a first resistive element, and the second branch has two second resistive elements connected in series; and a power supply terminal located between said two second resistive elements on the second branch. A high-precision reference voltage relative to the voltage source can be provided at the power supply terminal by using the circuit provided by various embodiments of the present invention.