DC-DC Voltage Converter Pulse-Skip Mode
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Solution Overview
Problem
Switched-mode DC-DC voltage converters experience reduced efficiency under light load conditions due to high switching losses in transistors, as existing operational modes are complex and typically control only one parameter, limiting their effectiveness.
Innovation Solution
The implementation of a pulse-skip operational mode in DC-DC voltage converters, utilizing a transconductance amplifier and current comparator to generate a ripple current that clamps the error voltage and selectively turns off transistors, reducing switching losses and maintaining high efficiency across varying load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional PWM mode is used under light load conditions, then the converter can maintain continuous operation, but switching losses in transistors become high relative to output power causing reduced efficiency
Solution Approach 1:
The patent implements pulse-skip mode where the converter operates in periodic intervals rather than continuous switching. Under light load conditions, the converter performs conversion operations periodically and enters skip modes between operations, reducing the frequency of switching events and thereby reducing switching losses while maintaining adequate output voltage regulation
Solution Approach 2:
The patent dynamically switches between pulse-width modulation mode and pulse-skip mode based on load conditions. The control system monitors output voltage and load current to determine when to transition between operational modes, optimizing efficiency across varying load conditions by adapting the switching strategy in real-time
2Productivity
If existing operational modes are used under light load conditions, then some efficiency improvement may be achieved, but the modes are complex and typically control only one parameter limiting their effectiveness
Solution Approach 1:
The patent employs a dual-loop control system where the outer voltage feedback loop and inner current feedback loop work together to control multiple parameters simultaneously. The voltage loop regulates output voltage while the current loop manages inductor current and enables pulse-skip operation, creating a unified control structure that handles both voltage regulation and efficiency optimization without requiring separate complex control circuits
Solution Approach 2:
The patent uses feedback from both voltage and current sensing to control the converter operation. The voltage feedback loop provides outer-loop regulation while the current feedback loop provides inner-loop control that enables intelligent skip decision-making, allowing the system to automatically adapt to load conditions and optimize efficiency without complex external control logic
Data Source
AI summary
DC-DC voltage converter systems are provided in which a switching voltage converter is arranged with an inductor to switch first and second currents with duty cycles D and D′ determined by an error voltage Verr to thereby maintain an output voltage Vout. A transconductance amplifier having an amplifier output provides the error voltage Verr in response to the output voltage and a reference voltage Vref. A ripple current Irpl is provided to the amplifier output in response to the difference between the error voltage Verr and a clamp voltage Vclmp. Finally, a current comparator generates a skip signal to turn off the first and second currents in response to a selected threshold of the ripple current. In this process, the ripple current Irpl substantially clamps the error voltage Verr to the clamp voltage Vclmp. Preferably, the current comparator is arranged to provide the skip signal in response to the selected first threshold of the ripple current Irpl and retract the skip signal in response to a selected second threshold of the ripple current Irpl.