DC/DC Converter Duty Cycle Difference Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional DC/DC converters have complex control circuitry and experience output glitches during mode transitions, with different efficiency curves for rising and falling input voltages, leading to suboptimal performance.
Innovation Solution
A DC/DC converter design that maintains a constant duty cycle difference between the buck and boost sections using a controller circuit with an error amplifier, state machine, and duty cycle generator, ensuring consistent performance regardless of input voltage changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different equations are used to generate duty cycles for buck and boost sections depending on input voltage direction, then mode transition control is achieved, but control circuitry complexity increases and output glitches occur
Solution Approach 1:
The patent applies homogeneity by using a single equation to generate duty cycles for both buck and boost sections regardless of whether input voltage is rising or falling. This unified approach eliminates the need for different equations in different modes, thereby reducing control circuitry complexity while maintaining reliable mode transition control through the constant duty cycle difference mechanism.
2Reliability
If different equations are used to generate duty cycles for buck and boost sections depending on input voltage direction, then mode transition control is achieved, but output glitches occur during transitions
Solution Approach 1:
By using the same equation for duty cycle generation in all operating modes and maintaining a constant duty cycle difference, the patent ensures smooth and continuous transitions between buck and boost modes. This homogeneous approach prevents abrupt changes in duty cycle calculations that would cause output glitches, while still achieving reliable mode transition control.
3Adaptability or versatility
If conventional duty cycle generation methods are used, then buck and boost modes are supported, but two different efficiency curves exist for rising and falling input voltages
Solution Approach 1:
The patent changes the parameter relationship by maintaining a constant duty cycle difference between buck and boost sections. This parameter constraint ensures that the converter operates optimally across the entire input voltage range, achieving a single consistent efficiency curve for both rising and falling input voltages while fully supporting both buck and boost operating modes.
Data Source
AI summary
According to an exemplary embodiment, a method includes the step (910) of driving a buck section of a DC/DC converter with a buck signal that has a buck duty cycle and concurrently with driving the buck section, driving a boost section of the DC/DC converter with a boost signal that has a boost duty cycle, a difference existing between the buck duty cycle and the boost duty cycle. The method also includes the step (920) of monitoring an input voltage that is coupled to the buck section for a change in the input voltage, and in response to a change in the input voltage, the step (930) of changing the buck duty cycle and the boost duty cycle such that the difference between the buck duty cycle and the boost duty cycle is substantially constant.