Power Converter Control Circuit With DC Offset Calibration
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Solution Overview
Problem
Existing power convertor circuits face challenges in responding quickly to load fluctuations, leading to instability and offset issues in reference and feedback voltages, which affect the stability and responsiveness of the output voltage.
Innovation Solution
A control circuit for power convertor circuits that includes a first ripple generation circuit, signal processing circuit, second ripple generation circuit with a DC offset calibration circuit, and comparison circuit to rapidly adjust the power stage operation based on ripple signal crossings, eliminating offsets between reference and feedback signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a ramp signal related to current is added to the reference voltage to increase loop stability, then the loop stability is improved, but the speed of response to load fluctuation becomes slow and offset problems occur in the reference voltage or feedback voltage
Solution Approach 1:
The patent segments the control circuit into multiple independent modules: first ripple generation circuit, signal processing circuit, second ripple generation circuit, and comparison circuit. Each module performs a specific function, allowing the system to maintain stability while responding quickly to load changes without the need for a ramp signal that would slow down the response.
Solution Approach 2:
The patent implements a feedback mechanism where the feedback signal related to output voltage is compared with the reference voltage signal through the DC offset calibration circuit and comparison circuit. This feedback loop continuously monitors and adjusts the output, maintaining stability and eliminating offsets without requiring additional ramp signals that would degrade response speed.
2Stability of the object's composition
If a ramp signal related to current is added to the reference voltage to increase loop stability, then the loop stability is improved, but offset problems occur in the reference voltage or feedback voltage
Solution Approach 1:
The patent introduces a DC offset calibration circuit as an intermediary component between the reference voltage signal and feedback signal paths. This calibration circuit actively compensates for and eliminates DC offsets, ensuring high measurement precision without requiring ramp signals that would introduce their own offset problems while maintaining loop stability.
3Productivity
If the control circuit uses traditional methods to respond to load fluctuation, then the circuit structure is simple, but the ability to respond to load fluctuation is poor
Solution Approach 1:
The control circuit is divided into specialized segments: first ripple generation circuit for generating ripple from phase voltage, signal processing circuit for filtering, second ripple generation circuit for generating reference ripple, and comparison circuit for decision-making. This segmentation enables rapid response to load fluctuations while keeping each module relatively simple and modular.
Solution Approach 2:
The patent utilizes periodic ripple signals generated by the first and second ripple generation circuits to continuously monitor and respond to load conditions. By comparing these periodic ripple signals, the control circuit can detect load changes and adjust accordingly, achieving high responsiveness through rhythmic, periodic measurement and control actions.
Data Source
AI summary
The present disclosure provides a power convertor circuit and a control circuit thereof. The power convertor circuit converts an input voltage signal to output an output voltage signal and includes a power stage circuit and a control circuit. The control circuit generates a first ripple signal according to a phase voltage signal outputted by the power stage circuit, generates a second ripple signal according to a DC signal generated by processing the first ripple signal, a reference voltage signal and a feedback signal related to the output voltage signal, and controls the power stage circuit to operate according to a preset off time when the second ripple signal continuously transcends the first ripple signal, to increase an inductor current. The control circuit calibrates the reference voltage signal by a DC offset calibration circuit, to eliminate an offset between the reference voltage signal and the feedback signal.