Multi-phase DC-to-DC Converter with Daisy-Chained PWM Control

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Solution Overview

Problem

Existing multi-phase DC-to-DC converters face inefficiencies in power conversion, integration into integrated circuits, and high costs, particularly due to susceptibility to voltage droop when loads suddenly draw increased current.

Innovation Solution

A scalable multi-phase DC-to-DC converter design featuring a master PWM generator and slave PWM generators connected in a daisy chain, with adaptive frequency adjustment and phase decoding, which uses current sense signals to adjust PWM signals and mitigate voltage droop through a feedback loop and adaptive clock frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional multi-phase DC-to-DC converters are used with parallel connected stages, then power conversion capability is improved, but voltage droop occurs when loads suddenly draw increased current

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidvoltage stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the master PWM generator receives feedback signals from slave PWM generators about their operating status. This allows the master controller to dynamically adjust the operation of slave converters, ensuring they operate within safe limits and preventing voltage droop by coordinating the switching phases based on real-time system conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the phase shift between master and slave PWM generators based on load conditions. The phase shift is not fixed but can be modified in response to changing current demands, allowing the multi-phase converter to adapt its power distribution strategy to maintain voltage stability under varying load conditions.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If multiple PWM generators are used in parallel, then power conversion efficiency is improved, but circuit complexity and integration difficulty increase

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidcircuit complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the PWM generation function into a master controller and multiple slave controllers. The master PWM generator handles high-level coordination and phase management, while slave PWM generators execute specific phase switching under master control. This segmentation allows efficient multi-phase operation while distributing circuit complexity across modular units that can be independently designed and integrated.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the control functions of multiple PWM generators into a coordinated system where the master controller consolidates phase management and synchronization tasks. By combining the control intelligence in the master unit and using simpler slave units for execution, the system achieves efficient power conversion while managing overall circuit complexity through functional integration.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If more phases are added to the converter, then power distribution capability is improved, but cost and integration difficulty increase

Engineering Contradiction:
Improvepower distribution capabilityVSAvoidintegration ease
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The slave PWM generators are designed as universal, multi-functional units that can operate in different phase configurations. Each slave generator can function with any number of phases by receiving appropriate phase shift instructions from the master controller. This universality allows the system to scale from 2-phase to N-phase configurations using the same basic slave unit design, improving power distribution capability while maintaining ease of manufacture through standardized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2328263B1Multi-phase DC-to-DC converter with daisy chained pulse width modulation generators
Publication Date: 2014.12.31 MONOLITHIC POWER SYSTEMS INC
  • EP2328263B1 patent drawingFigure 1
  • EP2328263B1 patent drawingFigure 2
  • EP2328263B1 patent drawingFigure 3

AI summary

A multi-phase DC-DC converter is disclosed. The DC-DC converter has a plurality of phases, each with a separate PWM generator for driving a totem pole of transistors. A master PWM generator operates off of a master clock signal. The remainder of the phases are slaved to the master PWM generator.