MIMO Switched-Capacitor DC-DC Converter for Multi-Voltage Hearing Aids

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Solution Overview

Problem

Modern hearing devices face inefficiencies in power conversion due to the use of multiple switched capacitor DC-DC converters, which increase volume, require high-voltage transistors, and cause electromagnetic interference, while existing solutions do not support multiple input voltages or simultaneous output voltages.

Innovation Solution

A multiple input multiple output (MIMO) switched capacitor DC-DC converter that receives multiple voltage inputs and provides multiple voltage outputs simultaneously, using an integrated voltage input demultiplexer to maintain efficient power conversion across a battery's discharge cycle, and can be implemented with thin-oxide devices in semiconductor process nodes, reducing complexity and EMI issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple SC DC-DC converters are used to provide multiple voltage levels, then power supply capability is improved, but power conversion efficiency deteriorates

Engineering Contradiction:
Improvepower supply capabilityVSAvoidpower conversion efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent combines multiple SC DC-DC converter functions into a single integrated converter that can simultaneously provide multiple voltage outputs. This merging approach maintains the ability to supply multiple voltage levels while improving overall power conversion efficiency by eliminating redundant conversion stages and reducing total energy loss across the system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single SC DC-DC converter is designed with multi-functionality to simultaneously generate multiple voltage outputs from a single input voltage. This universal converter can adapt its output configuration to provide different voltage levels as needed, replacing the need for multiple dedicated converters and maintaining versatility while improving efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple SC DC-DC converters are used, then voltage conversion capability is improved, but device volume increases

Engineering Contradiction:
Improvevoltage conversion capabilityVSAvoiddevice volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges multiple voltage conversion functions into a single integrated SC DC-DC converter, consolidating what would have been separate converter circuits into one compact unit. This integration dramatically reduces the total volume required while maintaining the capability to provide multiple voltage levels simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single converter is designed as a universal voltage conversion unit that can simultaneously produce multiple different voltage outputs. This multi-functional design eliminates the need for multiple separate converters, thereby reducing device volume while preserving comprehensive voltage conversion capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple SC DC-DC converters are used, then power conversion flexibility is improved, but system complexity increases

Engineering Contradiction:
Improvepower conversion flexibilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple converter control functions into a single integrated control system. By merging the control logic for multiple voltage outputs into one controller, the system maintains flexible power conversion capability while reducing the complexity associated with coordinating multiple independent converters, startup sequencing, and interdependent control circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single SC DC-DC converter incorporates universal control functionality that can adapt to provide different voltage configurations as needed. This multi-functional control approach simplifies the system architecture compared to managing multiple separate converters, reducing overall system complexity while maintaining power conversion flexibility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Power

If SC converters are used, then voltage conversion is achieved, but electromagnetic interference increases

Engineering Contradiction:
Improvevoltage conversionVSAvoidelectromagnetic interference
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent combines multiple switching operations into a single coordinated SC DC-DC converter system. By merging the switching functions and synchronizing the operation of a single converter providing multiple outputs, the system reduces the number of independent switching events that generate electromagnetic interference, thereby achieving voltage conversion with reduced EMI.

Inventive Principle:
Principle #5Merging (Combining)

5Power

If high-voltage power switches are used in SC converters, then voltage conversion capability is improved, but integrability in low-voltage IC processes deteriorates

Engineering Contradiction:
Improvevoltage conversion capabilityVSAvoidintegrability in low-voltage IC processes
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent employs parameter changes by utilizing thin-oxide devices that can operate at lower voltages while still achieving the required voltage conversion capability through the switched capacitor topology. This approach allows the converter to be manufactured using standard low-voltage CMOS processes, improving integrability while maintaining voltage conversion functionality.

Inventive Principle:
Principle #35Parameter changes

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 MIMO SC DC-DC converter replaces multiple converters, enhancing power conversion efficiency, reducing system complexity, and minimizing EMI, while allowing for efficient power supply as the battery depletes, and enabling higher integration and noise immunity in hearing devices.

Implementation Method 1

a multiple input multiple output, MIMO, switched capacitor, SC, DC-DC converter

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

configured for converting each voltage input to a voltage output of a different voltage

Methodology Applied
Scientific EffectElectrical energy conversion:

Data Source

PatentEP4492823A1Hearing device with multiple input multiple output DC-DC converter
Publication Date: 2025.01.15 GN HEARING AS
  • EP4492823A1 patent drawingFigure 1a~2
  • EP4492823A1 patent drawingFigure 3
  • EP4492823A1 patent drawingFigure 4

AI summary

The invention relates to a hearing device configured to be worn at an ear of a user. The hearing device comprises an input transducer adapted for capturing sound and providing a microphone input transducer signal based on the captured sound. The hearing device comprises a signal processing unit adapted for processing the input transducer signal and providing an output signal based on the processed input transducer signal. The hearing device comprises an output transducer adapted for providing a stimulation output signal based on the output signal. The hearing device comprises a battery configured for providing a battery cell voltage. The hearing device comprises a multiple input multiple output, MIMO, switched capacitor, SC, DC-DC converter coupled to the battery. The MIMO SC DC-DC converter comprises two or more inputs, each adapted for receiving a voltage input. The MIMO SC DC-DC converter comprises two or more outputs, each adapted for providing a voltage output of a different voltage from the other outputs. At least two of the two or more outputs can provide a voltage output simultaneously. The MIMO SC DC-DC converter is configured for converting each voltage input to a voltage output of a different voltage.