Voltage Comparison Circuit with Periodic Switching for Power Reduction

Solution Overview

Problem

Existing power supply management circuits in electronic devices face significant power consumption issues due to continuous current flow through operational amplifiers and resistors, affecting battery longevity and device operation efficiency.

Innovation Solution

A voltage comparison circuit is designed with a first unit for low power consumption and lower precision, and a second unit for high precision, activated only when a higher voltage is applied, reducing overall power usage and enabling efficient voltage selection between external and battery sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a voltage comparison circuit uses operational amplifiers and resistors continuously, then voltage comparison function is maintained, but power consumption increases

Engineering Contradiction:

Improvevoltage comparison functionVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by controlling the operational amplifier to operate only during specific periods when voltage comparison is needed, rather than continuously. The controller activates the operational amplifier based on detection signals, ensuring it operates periodically only when external power supply voltage needs to be compared with battery voltage, thereby reducing overall power consumption while maintaining the voltage comparison function when required.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies dynamics by making the operational amplifier's operating state changeable between active and inactive states. The controller dynamically adjusts the operational amplifier's operation based on system needs, switching it on when voltage comparison is required and off when not needed, thus transforming a static continuous operation system into a dynamic controllable system that optimizes power consumption.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If a voltage comparison circuit is always active, then voltage comparison precision is maintained, but battery longevity decreases

Engineering Contradiction:

Improvevoltage comparison precisionVSAvoidbattery longevity

Core Design Contradiction:

Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent implements periodic action by controlling the operational amplifier to operate only during specific periods when voltage comparison is needed, rather than continuously. The controller activates the operational amplifier based on detection signals, ensuring it operates periodically only when external power supply voltage needs to be compared with battery voltage, thereby reducing overall power consumption while maintaining the voltage comparison function when required.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies parameter changes by modifying the operational amplifier's operating parameters (on/off state) based on system requirements. The controller changes the operational amplifier's power supply state dynamically, switching between active and inactive modes, thus adjusting the power consumption parameter to extend battery longevity while preserving voltage comparison precision when needed.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If high precision voltage comparison is always performed, then voltage selection accuracy is improved, but power consumption increases

Engineering Contradiction:

Improvevoltage selection accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by controlling the operational amplifier to operate only during specific periods when voltage comparison is needed, rather than continuously. The controller activates the operational amplifier based on detection signals, ensuring it operates periodically only when external power supply voltage needs to be compared with battery voltage, thereby reducing overall power consumption while maintaining the voltage comparison function when required.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies local quality by providing high precision voltage comparison only in the specific local context where it is needed (when voltage selection is required), rather than uniformly across all operating conditions. The controller enables high precision comparison locally at the operational amplifier only when the system determines voltage comparison is necessary, accepting lower precision or no comparison in other contexts where power conservation is prioritized.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8639959B2Semiconductor apparatus having a controller arranged to turn on a first switch and turn off a second switch during a period in which a judgement unit judges a device type of a device

Publication Date: 2014.01.28 ROHM CO LTD

AI summary

A first switch is arranged between a judgment unit and a signal line. The first switch is turned on during a period in which the judgment unit judges a device, after which the first switch is turned off. A second switch is turned off during a period in which the judgment unit judges the device, after which the second switch is turned on. The signal line connects a communication interface port, which allows various different kinds of devices to be connected, and a communication terminal of a processor configured to perform data communication with the device. The judgment unit monitors the electrical state of the signal line, and judges the device connected to the port.