Voltage Selection Circuit for Seamless Dual-Supply Switching

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Solution Overview

Problem

Current voltage selector circuits in electronic devices require additional comparators, leading to extra power consumption and necessitate system interruptions during mode switching, preventing continuous operation.

Innovation Solution

A voltage selector device with a control circuit and selection circuit that adjusts a control node based on power enable signals and supply voltages to select the higher voltage level without interruption, ensuring continuous operation by maintaining a stable output voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional comparators are used in the voltage selector circuit, then voltage selection capability is improved, but power consumption increases

Engineering Contradiction:

Improvevoltage selection capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and eliminates the comparator component from the voltage selector circuit. Instead of using traditional comparators to determine which voltage source is higher, the invention uses a direct voltage selection mechanism where transistors are controlled based on voltage level detection, removing the power-consuming comparator while maintaining voltage selection capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the electronic comparator-based voltage comparison mechanism with a direct voltage-controlled transistor switching mechanism. The control circuit directly responds to voltage levels and controls transistor switching without mechanical or electronic comparators, substituting a power-intensive electronic comparison system with a more efficient voltage-controlled system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If system operations are interrupted during voltage mode switching, then operational errors are avoided, but productivity decreases

Engineering Contradiction:

Improveoperational error preventionVSAvoidcontinuous operation capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent enables continuous operation during voltage mode switching by maintaining power supply to the control circuit throughout the switching process. The control circuit remains powered and continues to monitor voltage levels, allowing seamless transition between voltage modes without interrupting system operations or causing operational errors.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The control circuit is designed to be powered up before the voltage switching occurs and remains powered during the entire switching process. This preliminary and continuous powering allows the control circuit to proactively manage the voltage switching, ensuring smooth transitions without system interruptions or operational errors.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If control circuit is powered up before voltage switching, then continuous operation is enabled, but power consumption increases

Engineering Contradiction:

Improvecontinuous operationVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic power management where the control circuit's power state changes based on operational needs. The control circuit is powered up before voltage switching to enable continuous operation, then powered down after switching completes to reduce power consumption. This dynamic power state adjustment balances continuous operation capability with power efficiency.

Inventive Principle:

Principle #15Dynamics

4Use of energy by moving object

If voltage switching is performed without control circuit powered up, then power consumption is reduced, but system reliability decreases

Engineering Contradiction:

Improvepower consumptionVSAvoidvoltage switching reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent requires the control circuit to be powered up before voltage switching occurs. This preliminary powering ensures the control circuit is active and capable of monitoring voltage levels and controlling the switching process, thereby ensuring reliable voltage switching. Only after successful switching does the control circuit get powered down to reduce power consumption.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12556174B2Voltage selector device

Publication Date: 2026.02.17 REALTEK SEMICON CORP

AI summary

A voltage selector device includes a control circuit and a selection circuit. The control circuit is configured to adjust a level of a control node according to a power enable signal, a first supply voltage, and a second supply voltage. When the first supply voltage is powered up and the second supply voltage is not powered up, the control circuit adjusts the level of the control node to a first level, and when the second supply voltage is powered up, the control circuit adjusts the level of the control node to a second level that is different from the first level. The selection circuit is configured to output, based on the level of the control node and second supply voltage, a selected one of the first supply voltage and the second supply voltage that has a higher voltage level as an output voltage.