Single-Inductor Multiple-Output DC-DC Converter with OPDC Control
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Solution Overview
Problem
Existing single-inductor multiple-output (SIMO) DC-DC converters face limitations in power delivery capability, conversion efficiency, and voltage ripple, especially under varying load conditions and battery voltage fluctuations, due to their operation in discontinuous conduction mode and high peak inductor current.
Innovation Solution
A SIMO DC-DC converter with a buck-boost output channel, pulse-skipping mode, and deadtime switch control is proposed, featuring an inductor coupled with input switches, output switches, and a freewheel switch, where the control circuit manages inductor current and feedback signals to optimize voltage regulation across multiple outputs, allowing sequential switching and freewheel duty cycles to enhance efficiency and adapt to different load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If time-multiplexing control scheme is used to support multiple outputs with one inductor, then component count is reduced and area is minimized, but peak inductor current becomes large and conversion efficiency decreases
Solution Approach 1:
The patent applies periodic action by implementing ordered-power-distributive control that distributes magnetic energy to multiple outputs sequentially within each switching period. The inductor current is discharged to multiple output nodes in a predetermined order during each clock cycle, allowing energy transfer to occur periodically rather than requiring complete charge-discharge cycles for each output individually. This reduces peak current requirements while maintaining multiple output capability.
2Measurement precision
If inductor current is discharged to zero for each output in TMC scheme, then cross regulation is removed, but total output current capability is limited and conversion efficiency is low
Solution Approach 1:
The patent implements continuity of useful action by operating the inductor in continuous conduction mode (CCM) where the inductor current never reaches zero. The ordered-power-distributive control ensures that the inductor current is continuously transferred to multiple output nodes in sequence without interruption. This continuous operation maintains higher average current levels, increasing total output current capability while preserving voltage regulation through the ordered distribution mechanism.
3Adaptability or versatility
If number of outputs is increased in TMC scheme, then multiple voltage requirements are met, but voltage ripple increases due to longer regulation time
Solution Approach 1:
The patent applies periodic action by distributing energy to multiple outputs sequentially within each switching period through ordered-power-distributive control. Each output receives its required energy in a predetermined order during the same clock cycle, completing regulation faster than traditional TMC schemes that process outputs sequentially across multiple periods. This periodic distribution within a single period reduces the total regulation time and consequently reduces voltage ripple.
4Device complexity
If inductor operates in discontinuous conduction mode with high peak current, then simple control is achieved, but thermal performance deteriorates and device size is limited
Solution Approach 1:
The patent applies parameter changes by transitioning the inductor operation from discontinuous conduction mode (DCM) to continuous conduction mode (CCM). This fundamental parameter change in the inductor's operating state allows the system to achieve both simplified control through ordered-power-distributive control and improved thermal performance through continuous current flow that eliminates high peak current stress and associated heating effects.
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 configuration improves power delivery capability, reduces switching losses, and achieves higher conversion efficiency while minimizing voltage ripple, enabling operation across a wide range of loads and battery voltage variations, including buck-boost mode for the highest output channel.
Implementation Method 1
an inductor coupled to a first input switch and a second input switch to store energy from supply source
Data Source
AI summary
Architecture and design techniques for a single inductor multiple-output (SIMO) DC-DC converter are presented. The SIMO DC-DC converter is based on ordered-power-distributive-control (OPDC) scheme with several novel control mechanism to optimize the performance of the power delivery capability, conversion efficiency and voltage ripple. In addition to buck mode outputs, the new SIMO DC-DC converter can also have an output channel operating at auto-buck-boost mode for the input voltage varying with the usage time.