SIMO DC-DC Converter Timing for Low Cross-Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional single-inductor multiple-output (SIMO) DC-DC converters face challenges in managing load variations across multiple outputs without compromising efficiency or increasing size and complexity, leading to cross-regulation issues.
Innovation Solution
A SIMO DC-DC converter design that uses an inductor to buffer energy and a control structure to generate control signals for input and output switches, allowing for precise timing of inductor energization and de-energization based on total current demand, thereby isolating load variations and reducing cross-regulation effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solutions are used to prevent or reduce the impact of load variations, then load regulation is improved, but energy efficiency decreases and space requirements increase
Solution Approach 1:
The control structure determines the duration of the first time segment (inductor energization phase) based on the sum of currents required by all loads before the conversion cycle begins. This preliminary determination allows the system to pre-calculate the energy storage requirements and adjust the inductor charging time accordingly, ensuring that sufficient energy is stored in the inductor to supply all loads during their respective time segments without requiring additional regulation circuitry that would consume extra energy or increase space
2Reliability
If conventional solutions are used to prevent or reduce the impact of load variations, then load regulation is improved, but device complexity increases
Solution Approach 1:
The conversion cycle is divided into multiple time segments, with the first time segment dedicated to inductor energization and subsequent time segments dedicated to supplying different loads. Each load is assigned a specific time segment during which it receives power from the inductor. This temporal segmentation allows a single inductor to serve multiple loads with different current requirements without requiring separate regulation circuits for each load, thereby reducing device complexity while maintaining reliable load regulation
Solution Approach 2:
A single inductor is used to supply power to multiple different loads during different time segments within the same conversion cycle. The inductor performs the universal function of energy storage and delivery for all loads, replacing what would traditionally require multiple dedicated inductors or complex multi-output regulation circuits. This multi-functionality approach reduces the number of components and simplifies the overall converter architecture
3Ease of operation
If the inductor is energized for a fixed duration, then control simplicity is maintained, but adaptation to varying total current demand decreases
Solution Approach 1:
The duration of the first time segment (inductor energization phase) is dynamically adjusted based on the total current demand from all loads. The control structure calculates the sum of currents required by each load and uses this information to determine the appropriate energization duration before the conversion cycle begins. This dynamic adjustment allows the system to adapt to varying load conditions while maintaining a relatively simple control architecture that operates in discrete cycles with predetermined time segments
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
The solution effectively maintains conversion efficiency while minimizing cross-regulation issues and maintaining constant load voltages, even with varying loads, without increasing size or complexity, making it suitable for high-volume production.
Implementation Method 1
an inductor connected to the input node and the output node and being configured to buffer energy; wherein in one time segment the inductor being energized, wherein the duration of the one time segment being determined by the control structure prior to a start of the cycle of operation, based on a sum of the set of currents suppliable to the plurality of loads
Data Source
AI summary
The invention relates to a single-inductor multiple-output (SIMO) DC-DC converter (1), comprising:an electrical DC voltage source (Vs) switchable connected to an input node (ni) through an input switch (S1, S2);a plurality of loads (Ro1, Ro2, RoN) each being switchable connected to an output node (no) through one output switch (So1, So2, SoN) of a plurality of output switches (So1, So2, SoN), wherein the electrical DC voltage source (Vs) and the loads (Ro1, Ro2, RoN) are external to the SIMO DC-DC converter (1);an inductor (L) connected to the input node (ni) and the output node (no) and being configured to buffer energy;a control structure arranged to operate in consecutive cycles and being configured to generate control signals for the input switch (S1, S2) and the output switches (So1, So2, SoN), wherein the inductor (L) being energized and de-energized in one cycle of operation (Tcycle) for supplying the plurality of loads (Ro1, Ro2, RoN) with a set of currents (Iact) within the said cycle of operation (Tcycle), wherein the control structure being configured to section the cycle of operation (Tcycle) into a plurality of consecutive time segments (tup, tdown) with a duration, wherein in one time segment (tup) the inductor (L) being energized, wherein the duration of the one time segment (tup) being determined by the control structure prior to a start of the cycle of operation (Tcycle), based on a sum of the set of currents (Iact) suppliable to the plurality of loads (Ro1, Ro2, RoN).The invention also relates to a method for operating a SIMO DC-DC converter (1).