Multiphase Switching Converter Control Circuit Reducing Voltage Overshoot
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Solution Overview
Problem
Constant ON-time controlled multiphase switching converters experience output voltage overshoot during fast load step-down transient processes, which affects performance and stability.
Innovation Solution
A control circuit for multiphase switching converters that includes a comparison circuit, an overshoot control circuit, and a switching control circuit, where the overshoot control circuit temporarily turns OFF a switching circuit when output voltage is detected overshooting and turns it back ON after a predetermined time period, ensuring the sum of ON and OFF periods meets a predetermined value, thereby reducing overshoot and improving transient response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If constant ON-time control is used to achieve fast transient response and simple circuit structure, then transient response speed and circuit simplicity are improved, but output voltage overshoot occurs during fast load step-down transient process
Solution Approach 1:
The patent implements a feedback mechanism by comparing the output voltage with a reference voltage to generate a comparison signal. When the output voltage exceeds the reference voltage during transient response, the feedback loop detects this condition and adjusts the switching circuit accordingly, preventing excessive overshoot while maintaining fast response characteristics.
Solution Approach 2:
The patent dynamically adjusts the ON-time of switching circuits based on real-time voltage conditions. Instead of using a fixed ON-time for all switching cycles, the control circuit modifies the ON-time duration according to the load conditions and voltage feedback, enabling adaptive control that prevents overshoot during transient states while maintaining simplicity.
2Power
If multiple switching circuits are used in multiphase configuration to improve current handling capability and heat performance, then power handling and thermal performance are improved, but circuit complexity increases
Solution Approach 1:
The patent divides the power conversion function into multiple independent switching circuits operating in parallel phases. Each phase handles a portion of the total current, distributing the power handling load and reducing thermal stress on individual components. The segmentation allows each circuit to operate independently while contributing to the overall system capability.
Solution Approach 2:
The patent merges multiple switching circuits into a unified multiphase architecture with shared control logic and common output. By combining the phases, the system achieves higher current capability and better thermal performance while the shared control elements reduce the overall complexity compared to having completely separate circuits for each phase.
Data Source
AI summary
A multiphase switching converter having a plurality of switching circuits and a control circuit, the plurality of switching circuits provide an output voltage, the control circuit provides a plurality of switching control signals to turn ON the plurality of switching circuits successively based on the output voltage and a reference signal, when the output voltage is detected overshooting, the control circuit turns OFF a current switching circuit, and when the output voltage is detected recovering from overshooting, the control circuit turns ON the current switching circuit again for a first time period until a sum of the first time period and a second time period achieves a predetermined value, wherein the second time period is a time period the current switching circuit maintains ON uninterruptedly before the output voltage is detected overshooting.