Switched-Capacitor Converter Startup Current Limiting

Solution Overview

Problem

Conventional switched-capacitor DC-DC converters require a hot swap circuit to manage input voltage, which increases the footprint and cost of power supplies and consumes power, making it undesirable.

Innovation Solution

An apparatus comprising a switched-capacitor converter, a monitor, and a controller that controls the switching of multiple switches to limit current input during startup, using pulse width modulation and frequency adjustments to manage the output voltage, eliminating the need for a hot swap circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hot swap circuit is implemented to manage input voltage during startup, then current in-rush is limited, but the footprint, cost, and power consumption of the power supply increase

Engineering Contradiction:

Improvecurrent in-rush limitationVSAvoidcircuit board footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent removes the hot swap circuit from the system entirely. Instead of using a separate hot swap circuit to limit current in-rush, the invention implements current limiting functionality directly within the switched-capacitor converter's control logic. The controller monitors output voltage during startup and adjusts switch states to limit input current, eliminating the need for the external hot swap circuit and its associated footprint and power consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent combines the current limiting function with the switched-capacitor converter's existing control mechanism. Rather than having a separate hot swap circuit perform current limiting, the controller integrates this functionality by monitoring output voltage and adjusting switch states accordingly. This merging eliminates redundant components and reduces overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If a hot swap circuit is implemented to manage input voltage during startup, then current in-rush is limited, but the cost and number of components increase

Engineering Contradiction:

Improvecurrent in-rush limitationVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the hot swap circuit from the system entirely. Instead of using a separate hot swap circuit to limit current in-rush, the invention implements current limiting functionality directly within the switched-capacitor converter's control logic. The controller monitors output voltage during startup and adjusts switch states to limit input current, eliminating the need for the external hot swap circuit and its associated footprint and power consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The controller in the switched-capacitor converter performs multiple functions: it manages normal voltage conversion operation and also handles startup current limiting by monitoring output voltage and adjusting switch states. This multi-functionality eliminates the need for dedicated startup protection components, reducing overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If a hot swap circuit is implemented to manage input voltage, then startup current is controlled, but power consumption increases

Engineering Contradiction:

Improvestartup current controlVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent removes the hot swap circuit from the system entirely. Instead of using a separate hot swap circuit to limit current in-rush, the invention implements current limiting functionality directly within the switched-capacitor converter's control logic. The controller monitors output voltage during startup and adjusts switch states to limit input current, eliminating the need for the external hot swap circuit and its associated footprint and power consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The switched-capacitor converter performs its own startup current limiting through internal control logic. The controller monitors the output voltage during startup and automatically adjusts the switch states to limit input current, eliminating the need for external active components that would consume power. The system serves its own startup protection needs without additional power-hungry components.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11502597B2Startup of a voltage converter

Publication Date: 2022.11.15 INFINEON TECH AUSTRIA AG

AI summary

A power supply system comprises: a switched-capacitor converter, a monitor, and a controller. The switched-capacitor converter includes an input node to receive an input voltage and an output voltage to output an output voltage. Switching of multiple switches in the switched-capacitor converter converts the input voltage into the output voltage. As its name suggests, the monitor monitors a magnitude of the output voltage. The controller receives input indicating the magnitude of the output voltage. Depending on the magnitude of the output voltage, the controller controls states of the multiple switches during startup of the switched-capacitor converter.