4-Phase Switched Capacitor Converter for High Ratios in Less Space
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switched Capacitor Power Converters (SCPCs) face limitations in voltage conversion ratios and require a large number of capacitors, especially when external floating capacitors are used, which hinders integration and increases package size and cost.
Innovation Solution
A novel 4-phase SCPC topology that utilizes only three floating capacitors to achieve a wide range of conversion ratios, reducing the number of component pins and enabling a more compact, integrated solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a higher number of capacitors is used to achieve a wider range of voltage conversion ratios, then the power efficiency is improved, but the package size and number of external capacitors increase
Solution Approach 1:
The patent combines multiple capacitor functions into a smaller number of capacitors by using a multi-phase switched capacitor topology. The first, second, and third capacitors perform multiple roles across different phases (first phase through fourth phase), enabling wide voltage conversion ratios without requiring a proportional increase in capacitor count. This merging reduces the overall number of external capacitors needed while maintaining power efficiency.
Solution Approach 2:
The patent employs dynamic reconfiguration of capacitor connections through multiple switching phases. The switched capacitor circuit dynamically changes the configuration of capacitors during operation, allowing the same capacitors to serve different functions at different times. This dynamic approach enables a wide range of voltage conversion ratios using fewer capacitors compared to static configurations.
2Adaptability or versatility
If external floating capacitors are used to achieve higher conversion ratios, then the voltage conversion capability is improved, but the number of package pins and integration density are reduced
Solution Approach 1:
Each capacitor in the patent is designed to perform multiple functions across different operating phases. The first capacitor, for example, serves different roles in the first phase versus the second phase, contributing to multiple voltage conversion ratios. This multi-functionality reduces the total number of capacitors and package pins required while maintaining versatile voltage conversion capability.
Solution Approach 2:
The patent uses periodic switching across four distinct phases to achieve wide voltage conversion ratios. By cycling through these phases periodically, the circuit can achieve multiple conversion ratios (such as 1:1, 2:1, 3:1, 4:1) using the same set of capacitors and switches, thereby reducing the need for additional components for each specific ratio.
3Reliability
If more capacitors are used to reduce current spike pulses and output ripples, then the output quality is improved, but the cost and area of the integrated solution increase
Solution Approach 1:
The multi-phase switched capacitor topology ensures continuous charge transfer to the output by overlapping the four phases. During each phase transition, capacitors are continuously charging and discharging, maintaining a steady output current and reducing ripple. This continuous action achieves high output quality without requiring additional capacitors beyond the three main capacitors.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for multi-phase high conversion ratio Switched Capacitor Power Conversion includes sequentially forming one of four subcircuits during a respective timing phase, wherein each subcircuit comprises at most three capacitors. Conversion between an input voltage of an input and an output voltage of an output occurs by sequentially connecting for each respective timing phase, one of the input, the output, a ground, a top plate of a first one of the three capacitors and a bottom plate of the first one of the three capacitors to one of a top plate of a second one of the three capacitors and a bottom plate of the second one of the three capacitors.