Step-up/down Power Supply Circuit Control Logic for Load Transients
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional step-up/down power supply circuits face challenges in responding effectively to abrupt changes in load and maintaining continuity during switching between step-down, step-up, and step-up/down operations, leading to inefficiencies in output voltage regulation.
Innovation Solution
A step-up/down power supply circuit design that includes a control logic circuit generating driving pulse signals based on clock signals, timing signals derived from comparisons of current feedback, slope compensation, and voltage difference signals, allowing for continuous adjustment of pulse widths of driving pulses to manage inductor current and maintain stable output voltage across different operational modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional step-up/down power supply circuit switching control is used, then the circuit can operate in step-up and step-down modes, but the response to abrupt load changes is slow and continuity is poor during mode switching
Solution Approach 1:
The patent implements dynamic switching control where the power supply seamlessly transitions between step-up and step-down modes based on real-time voltage comparisons. The control circuit dynamically adjusts the switching state of transistors Q1-Q4 and the configuration of inductors L1-L2 and capacitors C1-C2, allowing continuous adaptation to load changes without interruption or significant delay, thereby achieving both high reliability and fast response.
2Reliability
If conventional voltage regulation methods are used, then output voltage can be controlled, but ripples in output voltage persist
Solution Approach 1:
The patent ensures continuous voltage regulation by maintaining active control throughout the entire switching cycle. The control circuit continuously monitors the output voltage and adjusts the duty cycle of the switching transistors in real-time, preventing voltage ripples rather than merely responding to them. This continuous action ensures smooth transitions and stable output voltage throughout operation.
Solution Approach 2:
The patent employs feedback control where the output voltage is continuously monitored and compared with a reference voltage. The control circuit uses this feedback information to adjust the switching duty cycle, thereby regulating the output voltage and minimizing ripples. The feedback mechanism ensures that any deviation from the desired output voltage is quickly corrected, maintaining high stability.
3Adaptability or versatility
If conventional switching control is used, then the circuit can change operating modes, but losses increase during transitions
Solution Approach 1:
The patent prepares for mode transitions in advance by pre-charging or pre-discharging relevant capacitors and pre-positioning the switching transistors in optimal states before the actual transition occurs. This preliminary action minimizes the energy required during the switching event itself, reducing switching losses while maintaining the ability to quickly transition between step-up and step-down modes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution ensures consistent average inductor current before and after switching operations, thereby suppressing variations in output voltage and improving responsiveness to load changes, reducing losses and maintaining efficient power conversion.
Implementation Method 1
an inductance element that is connected between the step-down switching circuit and the step-up switching circuit
Data Source
AI summary
A first added signal that is acquired by adding a reference current signal that is in proportion to a current flowing through an inductance element, a slope compensation signal and a voltage difference signal that is in proportion to a difference between an input voltage and an output voltage and a second added signal that is acquired by adding the reference current signal and the slope compensation signal are compared with a difference signal of a voltage that is in proportion to the output voltage and a predetermined reference voltage, and pulse widths of driving pulse signals of a step-down switching circuit and a step-up switching circuit are controlled as a result of the comparison.