Adaptive PWM Control Circuit for Switching Converter Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional switching power converters using pulse width modulation (PWM) control with a constant frequency and on-time suffer from unsatisfactory conversion efficiency when the conversion ratio deviates from specific thresholds.
Innovation Solution
A conversion control circuit that adaptively adjusts the switching frequency of a switching power converter based on the conversion ratio, utilizing a trigger signal generation circuit, an on-time control circuit, and a logic driver circuit to adjust the on-time and off-time of the PWM signal accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If constant frequency PWM control is used, then the control is simple, but the conversion efficiency deteriorates when conversion ratio deviates from thresholds
Solution Approach 1:
The patent implements dynamic switching frequency adjustment by modifying the PWM control circuit to vary the switching frequency based on the conversion ratio. The control circuit monitors the conversion ratio and adaptively changes the switching frequency to maintain optimal efficiency across different operating conditions, transitioning from static constant frequency control to dynamic frequency modulation.
Solution Approach 2:
The patent changes the switching frequency parameter dynamically based on the conversion ratio. By establishing a relationship between conversion ratio and switching frequency, the system optimizes efficiency by adjusting this critical parameter according to actual operating conditions, rather than maintaining a fixed frequency.
2Speed
If switching frequency is increased, then the response speed improves, but the conversion efficiency deteriorates at extreme conversion ratios
Solution Approach 1:
The patent implements dynamic switching frequency adjustment by modifying the PWM control circuit to vary the switching frequency based on the conversion ratio. The control circuit monitors the conversion ratio and adaptively changes the switching frequency to maintain optimal efficiency across different operating conditions, transitioning from static constant frequency control to dynamic frequency modulation.
3Device complexity
If constant on-time control is used, then the control is simple, but the conversion efficiency deteriorates when conversion ratio exceeds thresholds
Solution Approach 1:
The patent implements dynamic switching frequency adjustment by modifying the PWM control circuit to vary the switching frequency based on the conversion ratio. The control circuit monitors the conversion ratio and adaptively changes the switching frequency to maintain optimal efficiency across different operating conditions, transitioning from static constant frequency control to dynamic frequency modulation.
Data Source
AI summary
A conversion control circuit, configured to control a switching power converter, includes a trigger signal generation circuit, an on-time control circuit, and a logic driver circuit. The trigger signal generation circuit is configured to generate a turn-on trigger signal. The on-time control circuit is configured to generate a turn-off trigger signal to determine the on-time and/or the off-time of a pulse width modulation (PWM) signal, and adjusts the on-time and/or the off-time according to the input voltage and the output voltage, such that the switching frequency of the switching power converter is adaptively adjusted according to a ratio between the output voltage and the input voltage. The logic driver circuit is configured to generate the PWM signal according to the turn-on trigger signal and the turn-off trigger signal, wherein the turn-on trigger signal enables the PWM signal, and the turn-off trigger signal disables the PWM signal.