Voltage Boosting Power Supply Circuit for Stable Output

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Solution Overview

Problem

Conventional charge pump power supply circuits face challenges in maintaining a predetermined output voltage across a wide range of supply voltages without changing settings, leading to issues such as noise generation and element breakdown due to fluctuating output voltages.

Innovation Solution

A voltage boosting power supply circuit that includes a voltage boosting capacitor, a first switch for charging, a second switch for boosting, an addition comparison circuit to sum the capacitor voltage and supply voltage, and a control circuit to manage the switches based on comparison results, ensuring the sum does not exceed a predetermined threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional charge pump power supply circuit is used to generate a driving voltage from a supply voltage, then the circuit can operate with various supply voltages, but the output voltage fluctuates and may exceed element breakdown voltage or generate noise

Engineering Contradiction:

Improveability to operate with various supply voltagesVSAvoidoutput voltage stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the output voltage is continuously monitored and compared with a reference voltage. Based on the comparison result, the control circuit adjusts the charging and discharging operations of the capacitor to maintain the output voltage within a safe range, preventing it from exceeding element breakdown voltage while ensuring stable operation across various supply voltages.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent employs dynamic control of the charge pump circuit by adjusting the charging and discharging timing based on voltage levels. The control circuit dynamically modifies the operation cycle to synchronize with the display clock, adapting the circuit behavior to maintain stable output voltage despite variations in supply voltage.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the output voltage is allowed to fluctuate to accommodate wide supply voltage range, then adaptability is improved, but noise generation and element breakdown risk increase

Engineering Contradiction:

Improvesupply voltage range compatibilityVSAvoidnoise and element breakdown

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The feedback control mechanism monitors the output voltage and compares it with a reference voltage. When the output voltage approaches unsafe levels, the control circuit adjusts the discharging timing to prevent voltage from exceeding element breakdown voltage, thereby eliminating noise and protecting elements while maintaining adaptability to wide supply voltage ranges.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control circuit performs preliminary control by predicting when the output voltage may exceed safe levels and adjusts the discharging operation in advance. By synchronizing the discharging cycle with the display clock and controlling the timing based on voltage monitoring, the circuit prevents noise generation and element breakdown before they occur.

Inventive Principle:

Principle #9Preliminary anti-action

3Device complexity

If the charge pump circuit operates independently without synchronization, then operational simplicity is maintained, but display quality deteriorates due to unsynchronized discharging

Engineering Contradiction:

Improvecontrol circuit simplicityVSAvoiddisplay quality

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The patent merges the charge pump control with the display clock synchronization mechanism. By aligning the capacitor discharging cycle with the display clock timing, the circuit ensures that voltage updates occur at appropriate display refresh moments, thereby improving display quality without significantly increasing control circuit complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 configuration allows for a stable output voltage across varying supply voltages without setting changes, preventing noise and element breakdown, thus enhancing display quality by synchronizing the discharging cycle with the display clock.

Implementation Method 1

a voltage boosting capacitor (21), a first switch (13) for applying a supply voltage (VDC) to the voltage boosting capacitor (21), thereby charging the capacitor (21)

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS8456404B2Voltage boosting power supply circuit for monitoring charging voltage with predetermined voltage to detect boosted voltage, and boosted voltage control method

Publication Date: 2013.06.04 RENESAS ELECTRONICS CORP

AI summary

A power supply circuit of the present invention includes a voltage boosting capacitor, a first switch, a second switch, an addition comparison circuit, and a control circuit. The first switch charges the voltage boosting capacitor by applying a first voltage thereto. The second switch connects a second voltage serially to the voltage boosting capacitor that is already charged, thereby boosting the voltage therein. The addition comparison circuit adds up the voltage of the voltage boosting capacitor and the second voltage and compares the comparison result, with a predetermined threshold value. The control circuit controls the on/off state of the first switch according to the comparison result of the addition comparison circuit.