Multi-Phase PWM Control Circuit for Current Balance Stability
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Solution Overview
Problem
Conventional multi-phase power supply controllers face issues of complex structure, large circuit size, high cost, and phase-to-phase current oscillation due to independent duty ratio control, which affects current balance accuracy.
Innovation Solution
A control circuit for multi-phase power conversion circuits that includes an error amplifier, pulse width modulation circuit, and multi-phase logic control circuit with width-preserving delay units to generate phase-delayed PWM signals, ensuring consistent pulse widths and reducing circuit size and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If each phase uses an independent PWM controller to control duty ratio, then the power conversion control is achieved, but the controller structure becomes complex and circuit size increases
Solution Approach 1:
The patent merges multiple independent PWM controllers into a single controller that generates PWM signals for multiple phases. The controller integrates the duty ratio control functionality for all phases, eliminating the need for separate PWM controllers in each phase while maintaining independent control capability through shared control circuitry.
Solution Approach 2:
The controller is designed with multi-functionality to serve multiple phases simultaneously. A single controller performs the duties of multiple PWM controllers by generating phase-shifted PWM signals for different phases, making the controller universal across all phases rather than dedicated to a single phase.
2Ease of operation
If each phase uses an independent PWM controller, then duty ratio control is achieved, but circuit cost increases
Solution Approach 1:
The patent combines multiple duty ratio control functions into a single controller circuit, reducing the total component count and circuit complexity. This merging approach lowers manufacturing costs by eliminating redundant controllers while preserving the ability to independently control duty ratios for each phase through integrated control logic.
3Adaptability or versatility
If independent duty ratio control is used in each phase, then power control flexibility is improved, but phase-to-phase current oscillation occurs
Solution Approach 1:
The patent incorporates feedback mechanisms that monitor phase currents and adjust duty ratios to maintain current balance across phases. The controller uses feedback signals from current sensors to dynamically adjust PWM duty cycles, preventing current oscillation while preserving control flexibility through adaptive regulation.
Solution Approach 2:
The controller employs periodic phase-shifting of PWM signals across phases, where each phase is activated in a sequential periodic manner. This periodic action distributes the power conversion load evenly across phases, reducing current oscillation while maintaining overall power control flexibility through the periodic switching pattern.
4Ease of operation
If multiple PWM controllers are used, then each phase can be controlled independently, but the circuit size becomes large
Solution Approach 1:
The patent merges multiple phase control functions into a single integrated controller, consolidating what would otherwise require multiple separate PWM controllers. This merging reduces the total circuit area by eliminating redundant control circuits while maintaining independent phase control capability through shared control resources and phase-shifting logic.
Data Source
AI summary
A control circuit for a multi-phase power conversion circuit and a multi-phase power supply are provided. The conversion circuit includes a plurality of switching circuits which have output terminals being coupled together to supply power to a load. The control circuit includes an error amplifier, a pulse width modulation circuit, and a multi-phase logic control circuit. The multi-phase logic control circuit generates a plurality of PWM signals according to an on time signal, which are delayed phase by phase and control on and off states of the plurality of switching circuits, and each of which has a pulse width being consistent with the on time signal. This reduces the circuit size and cost of the multi-phase power supply controller, and solves the problem of phase-to-phase current oscillation in a case that the switching circuits operate under duty ratios independent for various phases.