Multi-phase Master-slave Charging Circuit Thermal Management

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Solution Overview

Problem

Fast battery charging in mobile computing devices is hindered by high temperatures caused by inductor temperatures exceeding the charging circuit temperature, which existing technologies have not effectively addressed.

Innovation Solution

A multi-phase charging circuit configured in a multi-stage parallel configuration with selection circuitry to operate in 'master' or 'slave' modes, allowing for clock and control signal generation and synchronization, and using external inductive and capacitive elements to manage charging, thereby controlling temperature and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fast charging is implemented, then charging speed is improved, but temperature increases

Engineering Contradiction:
Improvecharging speedVSAvoidinductor temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent divides the charging system into multiple independent phases (first phase, second phase, third phase, fourth phase), each with its own charging circuit. By segmenting the single fast-charging path into multiple parallel paths, the current load on each individual inductor is reduced, thereby lowering the temperature rise while maintaining overall fast charging capability.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If inductor size is reduced, then device compactness is improved, but thermal performance deteriorates

Engineering Contradiction:
Improveinductor sizeVSAvoidinductor temperature
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The patent employs multiple smaller inductors distributed across different phases rather than one large inductor. Each phase has its own inductor, allowing the system to achieve the required total inductance while keeping individual inductor sizes small and their temperatures manageable through parallel operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-phase time-domain charging approach to a multi-phase spatial parallel architecture. By adding the phase dimension, the system distributes thermal load across multiple spatial locations, enabling smaller individual inductors with better thermal characteristics.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Temperature

If multi-phase parallel configuration is used, then thermal performance is improved, but system complexity increases

Engineering Contradiction:
Improvethermal performanceVSAvoidcircuit complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges multiple charging phases into a unified control architecture where a master controller coordinates slave controllers. The phases share common control logic and synchronization mechanisms, reducing the overall system complexity compared to having completely independent control systems for each phase.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements feedback control through master-slave coordination, where the master phase monitors and controls the operation of slave phases. This feedback mechanism ensures proper synchronization and current sharing, managing system complexity through intelligent control rather than purely hardware-based solutions.

Inventive Principle:
Principle #23Feedback

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 enables efficient battery charging with reduced thermal issues, allowing for smaller inductor sizes, improved thermal performance, and flexible system design, including current sharing among multiple chargers, resulting in reduced ripple and enhanced charging efficiency.

Implementation Method 1

The charging circuitry may include first and second charging circuits 202a, 202b and external inductive elements 14

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

external inductive and capacitive elements 14, 16 to manage charging

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3005514B1Master-slave multi-phase charging
Publication Date: 2020.07.29 QUALCOMM INC
  • EP3005514B1 patent drawingFigure 1
  • EP3005514B1 patent drawingFigure 1A~1B
  • EP3005514B1 patent drawingFigure 2

AI summary

A multi-phase charging circuit comprises a device that can be configured for master mode operation or slave mode operation. In master mode operation, the device generates a control signal and a clock signal to control operation of a switching circuit for generating charging current. In slave mode operation, the device receives externally generated control and clock signals to control operation of its switching circuit.