Power Supply Control Circuit With Switchable Output Capacitance

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Solution Overview

Problem

Switched-mode power supplies face high power consumption in standby mode due to the continuous supply of input power to control circuitry, which is not optimized for energy efficiency.

Innovation Solution

A control circuit that activates a second output capacitor in parallel with a first output capacitor during normal operating mode and deactivates it in standby mode, increasing output capacitance and reducing power losses by operating the converter stage in burst mode, thereby minimizing frequent activations and energy wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the control circuitry is continuously supplied with power in standby mode to detect load connection, then the power supply can quickly enter normal operating mode when load is connected, but the power consumption in standby mode increases

Engineering Contradiction:

Improvedetection capabilityVSAvoidstandby power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic sampling of the output voltage instead of continuous monitoring. The control circuit periodically measures the output voltage to detect load connection, rather than continuously supplying power to control circuitry. This periodic action maintains detection capability while significantly reducing standby power consumption.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent extracts the essential function of load detection from continuous power supply and implements it through voltage sampling. By taking out only the necessary measurement function and separating it from continuous operation, the system achieves detection capability with minimal power consumption in standby mode.

Inventive Principle:

Principle #2Taking out (Extraction)

2Stability of the object's composition

If a single large output capacitor is used to maintain output voltage during standby, then the voltage stability is maintained, but the capacitor size and associated losses increase

Engineering Contradiction:

Improveoutput voltage stabilityVSAvoidcapacitor losses

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent divides the output capacitance into two separate capacitors: a first output capacitor that remains connected during standby mode to maintain basic voltage stability, and a second output capacitor that is disconnected during standby but can be connected when full power is required. This segmentation allows the system to maintain adequate voltage stability with smaller capacitor losses during standby.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic switching of the second output capacitor based on operating mode. The control circuit dynamically connects or disconnects the second output capacitor according to whether the system is in standby mode or normal operating mode, optimizing the balance between voltage stability and power losses in real-time.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If the converter stage operates frequently in standby mode to maintain control circuitry power, then the control circuit remains active for quick response, but power losses increase due to frequent activations

Engineering Contradiction:

Improveresponse speedVSAvoidconverter activation losses

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent prepares the system for quick response by maintaining the control circuitry in a ready state through alternative power sources during standby, rather than relying on frequent converter activations. The output capacitor and control circuit are pre-configured so that when load is connected, the system can transition quickly without energy-wasting frequent converter start-ups.

Inventive Principle:

Principle #10Preliminary action

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

This solution significantly reduces power losses in standby mode by extending burst-off periods and decreasing the frequency of converter stage activations, enhancing energy efficiency and reducing power consumption.

Implementation Method 1

a second output capacitor connected in parallel with a first output capacitor of the power supply

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11901802B2Control circuit for a power supply and power supply with reduced standby power losses

Publication Date: 2024.02.13 INFINEON TECH AUSTRIA AG

AI summary

A control circuit, a power supply including a control circuit, and a method are disclosed. The control circuit is configured to activate a second output capacitor connected in parallel with a first output capacitor of a power supply when the power supply is in a normal operating mode, and deactivate the second output capacitor when the power supply is in a standby mode.