Multiphase DC-DC Converter Control via Fixed On-Time Pulse Division
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Solution Overview
Problem
Existing DC-DC converters face challenges in efficiently regulating output voltage across multiple phases, particularly in continuous conduction mode, leading to inefficiencies and increased system cost due to ripple current issues and the need for complex control mechanisms.
Innovation Solution
A control system comprising a pulse generator and frequency divider generates fixed on-time pulses triggered by current thresholds in alternating phases, dividing these pulses into phase signals to control N phases of a DC-DC converter, ensuring efficient output voltage regulation by alternately activating phases and adjusting duty cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If DC-DC converters operate in continuous conduction mode to maintain stable output voltage, then output voltage stability is improved, but efficiency deteriorates due to increased ripple current and higher energy losses
Solution Approach 1:
The patent divides a single continuous conduction mode converter into multiple phases that operate in alternating intervals. Each phase operates in discontinuous conduction mode during its active interval, segmenting the continuous operation into discrete phases that collectively maintain stable output while improving efficiency by reducing ripple current amplitude.
2Object-generated harmful factors
If multiple DC-DC converter phases are used to reduce ripple current, then ripple current amplitude is reduced, but device complexity increases due to additional control mechanisms
Solution Approach 1:
The patent implements periodic switching of multiple phases where each phase is activated in alternating intervals. This periodic action naturally distributes the ripple current across phases, reducing the overall amplitude without requiring complex control mechanisms. The alternating activation pattern simplifies the control logic compared to continuous multi-phase coordination.
3Loss of energy
If discontinuous conduction mode is used to improve efficiency at light loads, then energy efficiency is improved, but output voltage regulation deteriorates due to increased voltage ripple
Solution Approach 1:
The patent merges multiple phases operating in discontinuous conduction mode into a unified system where their combined output maintains stable voltage regulation. By combining the outputs of alternating phases, the system achieves both the efficiency benefits of discontinuous conduction mode and the voltage stability of continuous operation, as the phases complement each other's output characteristics.
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
This solution enhances the efficiency of DC-DC converters by effectively regulating output voltage, reducing ripple current amplitude, and simplifying control mechanisms, thereby improving overall system performance and cost-effectiveness.
Implementation Method 1
Inductor 106 stores energy in the magnetic field created by current flowing through the inductor during this first interval
Data Source
AI summary
A control system for regulating an output voltage of a DC-DC converter having N phases, where N is an integer greater than one, includes a pulse generator and a frequency divider. The pulse generator generates a stream of fixed on-time pulses, each pulse triggered in response to current through an alternating one of the N phases falling to a threshold value. The frequency divider divides the stream of fixed on-time pulses into N phase signals for controlling the N phases. A method for regulating an output voltage of a DC-DC converter having N phases, includes the following steps: (1) generating a stream of fixed on-time pulses, each pulse triggered in response to current through an alternating one of the N phases falling to a threshold value, and (2) dividing the stream of fixed on-time pulses into N phase signals for controlling the N phases.