Multiphase DC-DC Converter with Configurable Current Sharing
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Solution Overview
Problem
Multiphase DC-DC converters face a design trade-off between power efficiency and load transient performance, particularly in turbo mode operations, where increasing inductance for higher efficiency degrades transient performance, and conventional designs with same inductance values for all phases fail to optimize power conversion across varying load conditions.
Innovation Solution
Implementing configurable current sharing ratios and phase management by using phase circuits with different inductance values, where higher inductance inductors operate at lower switching frequencies for light to medium loads and lower inductance inductors are added for turbo modes, along with dynamic thermal management to balance phase temperatures by adjusting current sharing ratios and phase sequences based on placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If inductance is increased to improve power efficiency, then power conversion efficiency is improved, but load transient performance is degraded
Solution Approach 1:
The patent implements dynamic inductance selection by configuring different inductance values for different phase circuits. The system dynamically selects which phases to activate based on load conditions, using higher inductance phases for light loads (improving efficiency) and lower inductance phases for heavy loads (maintaining transient performance). This dynamic reconfiguration resolves the contradiction by adapting the inductance characteristic to the operating condition.
Solution Approach 2:
The patent changes the inductance parameter across different phases and operating conditions. By providing phase circuits with different inductance values and selectively activating them based on load current requirements, the system optimizes the inductance parameter for each operating regime, achieving both high efficiency at light loads and good transient response at heavy loads.
2Device complexity
If same inductance values are used for all phases to simplify design, then device complexity is reduced, but power conversion efficiency across varying load conditions is degraded
Solution Approach 1:
The patent applies local quality by assigning different inductance values to different phase circuits based on their specific roles. Higher inductance is assigned to phases intended for light-load operation, while lower inductance is assigned to phases for heavy-load operation. This localized differentiation optimizes efficiency across varying load conditions without requiring complete redesign of all phases.
Solution Approach 2:
The patent segments the phase circuits into different inductance groups (higher inductance phases and lower inductance phases). This segmentation allows independent optimization of each group for specific operating conditions, with the controller selecting appropriate phase combinations based on load requirements, thereby improving overall efficiency without uniform complexity increase.
3Loss of energy
If higher inductance is used to reduce AC losses, then efficiency at light load conditions is improved, but transient response speed is degraded
Solution Approach 1:
The patent implements dynamic switching between different inductance configurations. At light load conditions, higher inductance phases are activated to minimize AC losses and maximize efficiency. When transient response is required (heavy load conditions), the controller switches to lower inductance phases that provide faster response. This dynamic adaptation resolves the speed-efficiency trade-off.
Solution Approach 2:
The patent employs periodic phase activation patterns where different phase combinations are activated based on operating conditions. The controller periodically evaluates load conditions and switches between higher inductance configuration (for efficiency) and lower inductance configuration (for speed), creating a periodic adaptation cycle that optimizes both AC losses and transient response across varying operating conditions.
Data Source
AI summary
A multiphase DC-DC converter includes a first phase circuit including a higher inductance inductor and a second phase circuit including a lower inductance inductor. An output of the inductors are tied together providing a Vout. A phase manager and current sharing (PMCS) block receives a feedback signal from a feedback network coupled between Vout and the PMCS block that receives current feedback from phase circuits. The PMCS block generates driver control signals at a first time when a load is requesting a lower load current for controlling the phase circuits to operate with a first current sharing ratio to provide the lower load current, and at a second time when the load is requesting a higher load current controls the phase circuits to operate at a second current sharing ratio that is different from the first current sharing ratio having a higher average second phase circuit current.