Multiphase Switching Power Supply Current Limiting With Feedback Integration
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Solution Overview
Problem
Conventional switching power supplies face challenges in achieving high current accuracy and fast current limiting due to variations in inductance values among phases, particularly in multi-phase conversion circuits, leading to poor over-current protection.
Innovation Solution
A control circuit and method that integrates an error between a compensation signal and a voltage signal to generate a current reference signal, which is used to control each phase power conversion circuit, allowing for fast and precise current limiting by adjusting the control signal based on the integration signal and compensation signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional peak current mode control is used for fast over-current protection, then response speed increases, but current accuracy deteriorates due to inductance variations among phases
Solution Approach 1:
The patent introduces a feedback mechanism where the current reference signal is adjusted based on feedback from the actual output current. The controller compares the actual current with the reference current and modifies the current reference signal accordingly, enabling accurate current control despite inductance variations among phases. This feedback loop resolves the contradiction by maintaining both fast response and high accuracy.
Solution Approach 2:
The patent dynamically changes the current reference signal parameter based on operating conditions. By adjusting the current reference signal according to feedback from actual current measurements, the system adapts to inductance variations among phases while maintaining accurate current control and fast response speed.
2Manufacturing precision
If multi-phase conversion circuit architecture is used to reduce voltage ripple, then voltage ripple elimination improves, but device complexity increases
Solution Approach 1:
The patent merges multiple phase conversion circuits into a unified multi-phase architecture with common control. By combining N-phase power conversion circuits under a single controller that uses integrated current reference signal generation, the system achieves superior voltage ripple elimination while managing complexity through shared control resources rather than independent control for each phase.
Solution Approach 2:
The controller is designed with universal functionality to handle N-phase power conversion circuits simultaneously. The single controller generates current reference signals for all phases and processes feedback from all phases, making the control system multi-functional and reducing overall device complexity compared to having separate control circuits for each phase.
3Reliability
If conventional current limiting methods are used, then over-current protection is provided, but current limiting accuracy deteriorates due to inductance variations
Solution Approach 1:
The patent employs feedback control where the current reference signal is continuously adjusted based on actual current measurements from all phases. This feedback mechanism ensures accurate current limiting by compensating for inductance variations among phases, maintaining both reliable over-current protection and high current limiting accuracy.
Solution Approach 2:
The system dynamically changes the current reference signal parameter to achieve accurate current limiting. By adjusting the reference current based on feedback and operating conditions, the patent overcomes inductance variations among phases and achieves precise current limiting for reliable over-current protection.
Data Source
AI summary
The present disclosure relates to a switching power supply, and a control circuit and a control method of the switching power supply. The switching power supply comprises N-phase power conversion circuits, N being an integer greater than or equal to 1. The control circuit comprises a current reference signal generating means and a control means. The current reference signal generating means is configured to obtain an integration signal by integrating an error between a first compensation signal and a first voltage signal, and obtains a current reference signal by adding the integration signal and the first compensation signal. The control means provides control signals for respective ones of the N-phase power conversion circuits in accordance with the current reference signal. The first compensation signal represents a difference information between an output feedback signal of the switching power supply and a predetermined reference voltage.