Multiple-Level Switched-Mode Power Supply for Display Drivers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switched-mode power supply circuits for display screens, such as LCD and AMOLED, face issues with high power dissipation due to resistive dividers and inadequate electrostatic discharge protection, particularly in generating multiple voltage levels required for column drivers.
Innovation Solution
A multiple-level power supply circuit utilizing a reversible buck-type switched-mode converter with a capacitive dividing bridge and diodes for electrostatic discharge protection, allowing for efficient voltage sampling and maintaining intermediary potentials, while ensuring safe operation and reduced dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a resistive divider is used to generate intermediary voltage, then the voltage division is simple, but power dissipation increases significantly
Solution Approach 1:
The patent changes the operating parameters by using a switched-mode converter instead of a resistive divider, transforming the voltage generation mechanism from continuous resistive division to pulsed inductive switching, thereby reducing power dissipation while maintaining voltage generation capability
Solution Approach 2:
The patent replaces the passive resistive voltage division mechanism with an active switched-mode power conversion system using inductors, capacitors, and controlled switches, substituting a high-dissipation electrical mechanism with a more efficient electromagnetic conversion system
2Use of energy by moving object
If a boost converter is used to generate high voltage VR, then the voltage conversion is efficient, but electrostatic discharge protection becomes inadequate
Solution Approach 1:
The patent segments the voltage generation system into two independent converters (boost converter for VR and buck converter for V1) with separate ESD protection paths, allowing each converter to have dedicated protection mechanisms that address their specific electrostatic discharge vulnerabilities
Solution Approach 2:
The patent introduces intermediary protection diodes (D1, D2, D3) and a protection transistor (T1) that act as mediators between the converters and external electrostatic discharge events, providing a controlled path for discharge currents that protects the sensitive switching components
3Power
If column drivers are designed for high voltage operation, then they can drive display cells effectively, but integration and miniaturization become difficult
Solution Approach 1:
The patent adds a voltage dimension by introducing an intermediary voltage level (V1) between ground and the high voltage (VR), enabling column drivers to operate at lower voltage levels while still being able to drive high-voltage display cells through switched configurations
Solution Approach 2:
The patent implements dynamic voltage switching in the column drivers, where switches alternately connect to different voltage levels (VR and V1) based on the required output, allowing the driver circuitry to handle high-voltage signals while the internal components operate at lower, more integrable voltage levels
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 solution significantly reduces power dissipation and enhances electrostatic discharge protection, enabling stable operation of display screens by efficiently generating and managing multiple power supply voltages, thus improving the reliability and efficiency of power supply circuits.
Implementation Method 1
A multiple-level power supply circuit utilizing a reversible buck-type switched-mode converter
Implementation Method 2
a capacitive dividing bridge connects said first and second terminals, the midpoint of the capacitive dividing bridge corresponding to the output of the second converter and defining a third terminal of provision of an intermediary potential
Data Source
AI summary
A circuit for providing at least two power supply voltages from a D.C. voltage provided by a first switched-mode converter between a first and a second terminals, wherein: a second reversible buck-type switched-mode converter is powered with said D.C. voltage; a capacitive dividing bridge connects said first and second terminals, the midpoint of the capacitive dividing bridge corresponding to the output of the second converter and defining a third terminal of provision of an intermediary potential; and said two power supply voltages are respectively sampled between the first and third and between the third and second terminals.