Adaptive Switching Frequency Control for Stable Power Converters
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Solution Overview
Problem
Conventional power converters supply output voltage signals with unstable voltages and ripple waves due to switching the high-side and low-side switches at a constant frequency, which is inadequate for handling changes in input voltage.
Innovation Solution
A power converter that includes a feedback circuit, frequency adjusting circuit, control circuit, and driver circuit to adaptively adjust the frequency of the high-side and low-side switches based on input voltage changes, ensuring soft switching and reducing ripple waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the switching frequency is kept constant in a conventional power converter, then the device complexity is reduced and ease of operation is improved, but the output voltage stability deteriorates and ripple waves increase when input voltage changes
Solution Approach 1:
The patent implements dynamic frequency adjustment by introducing a frequency adjusting circuit that modifies the switching frequency based on input voltage conditions. The control circuit adaptively changes the frequency of the clock signal that drives the switching devices, transitioning from a static fixed-frequency approach to a dynamic variable-frequency approach that responds to changing operating conditions, thereby resolving the contradiction between operational simplicity and voltage stability.
Solution Approach 2:
The patent changes the switching frequency parameter in response to input voltage variations. The frequency adjusting circuit detects input voltage changes and adjusts the clock signal frequency accordingly, allowing the power converter to maintain stable output voltage by optimizing the switching frequency parameter under different operating conditions, thus resolving the stability issue while maintaining ease of operation through automated parameter adjustment.
2Stability of the object's composition
If the switching frequency is increased to reduce ripple waves, then the output voltage stability is improved, but the device complexity increases due to additional frequency adjustment circuits
Solution Approach 1:
The control circuit in the patent is designed to perform multiple functions: it generates control signals for switching devices, adjusts switching frequency based on input voltage, and maintains output voltage stability. By making the control circuit multi-functional, the patent avoids adding separate dedicated frequency adjustment circuits, thus improving output voltage stability while minimizing the increase in device complexity.
Solution Approach 2:
The patent merges the frequency adjustment function with the existing control circuit that manages switching devices. The frequency adjusting circuit is integrated into the control architecture, combining voltage regulation and frequency adjustment functions in a unified control system, thereby reducing overall device complexity while achieving improved output voltage stability through adaptive frequency control.
3Stability of the object's composition
If adaptive frequency adjustment is implemented to improve output voltage stability, then the output voltage stability is improved, but the control complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the frequency adjusting circuit continuously monitors input voltage conditions and adjusts the switching frequency accordingly. This closed-loop feedback control allows the system to automatically maintain optimal switching frequency for stable output voltage without requiring complex manual control algorithms, thereby improving stability while managing control complexity through intuitive feedback-based adjustment.
Solution Approach 2:
The control circuit is designed to automatically adjust the switching frequency based on detected input voltage conditions without external intervention. The frequency adjusting circuit self-regulates the operating parameters by monitoring system state and making appropriate frequency modifications, enabling the power converter to maintain stability autonomously and reducing the need for complex external control systems.
Data Source
AI summary
A power converter for adaptively adjusting a frequency is provided. The power converter includes a high-side switch, a low-side switch, a feedback circuit, a frequency adjusting circuit, a control circuit and a driver circuit. The feedback circuit outputs a regulation on-time signal according to a voltage signal of a node between a second terminal of an inductor and a first terminal of a capacitor. When the frequency adjusting circuit determines that a duty cycle of a waveform of the regulation on-time signal is not larger than a duty cycle of a waveform of a minimum on-time signal, the frequency adjusting circuit adjusts a frequency of a clock signal. The control circuit outputs a control signal according to the adjusted clock signal. The driver circuit drives the high-side switch and the low-side switch according to the control signal.