SIMO DC-DC Converter Control for Lower Cross-Regulation
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Solution Overview
Problem
Conventional single inductor multiple-output (SIMO) DC-DC converters experience high dynamic power dissipation due to parasitic capacitance and cross-regulation between output voltages, leading to instability and inefficiency in power management for varying loads.
Innovation Solution
A method for DC-DC conversion that selectively charges and discharges output capacitors based on voltage levels and energy thresholds, using processors to prioritize capacitor selection and manage inductor current, reducing parasitic effects and cross-regulation through non-periodic switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional SIMO DC-DC converters use periodic switching to maintain output voltages, then voltage regulation is achieved, but cross-regulation between outputs occurs and dynamic power dissipation increases
Solution Approach 1:
The patent applies periodic action by using fixed-frequency switching for each output capacitor independently. Each output capacitor is charged periodically when its voltage drops below a reference level, creating non-synchronized periodic charging cycles that eliminate cross-regulation while maintaining voltage regulation through repeated charging actions.
Solution Approach 2:
The patent segments the control of multiple output capacitors by giving each capacitor an independent control signal generated by its own voltage detection circuit. This segmentation allows each output to be regulated independently without affecting others, eliminating cross-regulation issues that occur in conventional unified control schemes.
2Loss of energy
If switching frequency is reduced to minimize dynamic power dissipation, then power efficiency improves, but voltage regulation response time increases
Solution Approach 1:
The patent applies partial action by charging each output capacitor only when its voltage falls below a reference level, rather than continuous charging. This conditional periodic charging reduces unnecessary switching operations and dynamic power dissipation while maintaining adequate voltage regulation response when needed.
3Adaptability or versatility
If multiple inductors are used in LC DC-DC converters to provide multiple power supplies, then power conversion flexibility improves, but electromagnetic interference and component cost increase
Solution Approach 1:
The patent merges multiple inductor functions into a single shared inductor that serves all output capacitors. This single inductor is periodically charged and discharged to supply multiple outputs, reducing electromagnetic interference from multiple inductors while maintaining power conversion flexibility through independent control of each output capacitor charging cycle.
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
Enhances power efficiency and stability by minimizing dynamic power dissipation and cross-regulation, improving noise immunity and robustness to load variations.
Implementation Method 1
an inductor may operate as a current storage element that transfers energy from input voltage to output voltages
Implementation Method 2
a respective output capacitor may be needed as a voltage storage element that maintains an output voltage
Data Source
AI summary
A method for direct current (DC)-DC conversion. The method includes converting an input voltage to a set of output voltages by selecting a first output capacitor in a set of output capacitors of a DC-DC converter, charging an inductor of the DC-DC converter, and discharging an electric current passing through the inductor into the first output capacitor. The first output capacitor is selected responsive to a voltage level of the first output capacitor being less than a first reference voltage in a set of reference voltages. The inductor is charged by applying the input voltage to the inductor. The first output capacitor maintains a first output voltage in the set of output voltages.