Buck-Boost Power Converter On-Time Compensation for Stable Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power converters face inefficiencies due to the inability of controller circuits to effectively control the on-times of switch components, leading to low operating frequencies and inadequate power supply to loads.
Innovation Solution
A power converter with an on-time compensation mechanism that adjusts the on-times of switch components in buck mode based on the on-times of switch components in boost mode, using a control circuit to ensure equal on-times in buck-boost mode, thereby optimizing switching frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the conventional controller circuit directly adds the on-times of switch components in buck mode to the on-times of switch components in boost mode, then the control method is simple, but the switching frequency becomes too low causing low operating efficiency
Solution Approach 1:
The patent implements dynamic on-time adjustment by introducing compensation mechanisms that adaptively modify the on-times of switch components based on operating conditions. The control circuit dynamically calculates compensated on-times using formulas that consider input voltage, output voltage, and original on-times, allowing the system to optimize switching frequency across different operating modes (buck, boost, buck-boost) rather than using fixed additive timing
Solution Approach 2:
The patent changes the timing parameters by introducing compensation values (Ton1_comp, Ton2_comp, Ton3_comp, Ton4_comp) that adjust the original on-times. These compensated on-times are calculated using specific formulas that incorporate voltage ratios and original on-time values, transforming the simple additive approach into a parameter-adjusted approach that maintains appropriate switching frequencies across different operating modes
2Device complexity
If the conventional controller circuit uses simple on-time addition, then the control circuit design is straightforward, but the power converter cannot effectively supply power to the load
Solution Approach 1:
The patent implements feedback mechanisms where the control circuit continuously monitors operating conditions and adjusts the on-times of switch components accordingly. The compensated on-time calculations incorporate feedback from voltage measurements and original on-time values, creating a closed-loop control system that ensures reliable power supply to the load while maintaining optimal switching characteristics across different operating modes
Solution Approach 2:
The patent applies preliminary compensation calculations to determine the appropriate on-times before switching operations begin. By pre-calculating the compensated on-times based on expected operating conditions and voltage levels, the control circuit prepares optimal timing parameters in advance, ensuring reliable power supply capability from the start of each switching cycle
Data Source
AI summary
A power converter having an on-time compensation mechanism is provided. The power converter includes a first switch, a second switch, a third switch, a fourth switch and a control circuit. A first terminal of the first switch is coupled with an input voltage. A first terminal of the second switch is connected to a second terminal of the first switch and a first terminal of an inductor. A first terminal of the fourth switch is connected to a second terminal of the third switch and a second terminal of the inductor. The control circuit, according to an on-time of the fourth switch operating in a boost mode, compensates on-times of the first and the second switches operating in a buck mode. In a buck-boost mode, the control circuit controls the on-times of the first and the second switches to be equal to the compensated on-times, respectively.