Active Droop Control for Phase Current Sharing in Power Supplies
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Solution Overview
Problem
Conventional power supplies face challenges in achieving accurate phase current sharing among multiple phases due to droop mismatches and PCB layout asymmetries, leading to inefficiencies and imbalances in output voltage and current distribution.
Innovation Solution
A power supply system with enhanced phase current sharing is implemented, utilizing active droop control and digital calibration. Each power module includes a digital controller connected to a communication bus, an RC circuit to sense analog output voltage droop, and a communication network to align load lines and compensate for PCB resistances and inductor differences, ensuring precise phase current balancing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional power supplies use multiple phases for power distribution, then power delivery capacity increases, but phase current sharing accuracy deteriorates due to droop mismatches and PCB layout asymmetries
Solution Approach 1:
The patent implements a feedback mechanism where the digital controller continuously monitors the output voltage droop of each phase and adjusts the duty cycle accordingly. The RC circuit senses the analog output voltage droop, and this information is fed back to the digital controller which modifies the PWM duty cycle to compensate for droop mismatches, thereby achieving accurate phase current sharing while maintaining high power delivery capacity
Solution Approach 2:
The patent dynamically changes the duty cycle parameter of each phase based on the sensed output voltage droop. By adjusting the duty cycle in response to droop conditions, the system compensates for PCB layout asymmetries and inductor differences, enabling accurate current sharing across multiple phases without sacrificing power delivery capability
2Manufacturing precision
If active droop control is implemented to compensate for droop mismatches, then phase current sharing accuracy improves, but system complexity increases due to additional sensing and control circuitry
Solution Approach 1:
The patent merges the droop sensing function with the existing output voltage sensing node. The RC circuit is connected across the output inductor and output voltage node, utilizing the same nodes already present in the power converter. This integration approach enables droop detection without adding separate sensing circuits, thereby improving phase current sharing accuracy while minimizing the increase in system complexity
3Measurement precision
If RC circuits are added to sense analog output voltage droop for each power module, then droop detection precision improves, but manufacturing cost and device complexity increase
Solution Approach 1:
The RC circuit serves multiple functions: it senses the analog output voltage droop, filters the voltage signal, and provides feedback to the digital controller. By making the RC circuit multi-functional, the patent achieves precise droop detection without requiring separate dedicated sensing circuits, thereby improving measurement precision while limiting the increase in device complexity to the minimum necessary components
Data Source
AI summary
A system, power supplies, controller and method for enhanced phase current sharing are disclosed. For example, a power supply for enhanced phase current sharing is disclosed, which includes a plurality of power modules, a communication bus coupled to an input of each power module of the plurality power modules, and an output voltage node coupled to a first side of an inductor of each power module of the plurality of power modules, wherein each power module of the plurality of power modules includes a digital controller coupled to the input of the power module, and an RC circuit enabled to generate a feedback signal, coupled to a second side of the inductor and the output voltage node. In some implementations, the power supply is at least part of a power management integrated circuit (PMIC) or at least part of a power supply formed on a semiconductor IC, wafer, chip or die.