DC-DC Converter Switch Integration for OLED Power Efficiency
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Solution Overview
Problem
Conventional DC-DC converters for organic light emitting displays have high power consumption and increased size and weight due to freewheel diodes, which cannot be truly shut down, leading to continuous power supply and display deterioration.
Innovation Solution
A DC-DC converter design featuring a boost converter and an inverter with integrated switching controllers, utilizing switches instead of freewheel diodes to control power flow, allowing for true shutdown via an enable signal, reducing power consumption and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional DC-DC converter with freewheel diodes is used, then power conversion function is achieved, but power consumption increases and size increases
Solution Approach 1:
The patent merges the freewheel diode function with the switching controller by integrating a rectifier circuit inside the switching controller. This eliminates the need for external freewheel diodes, reducing both power consumption (no 0.4-0.7V voltage drop) and device size/weight, while maintaining the power conversion function.
Solution Approach 2:
The patent introduces a rectifier circuit as an intermediary component within the switching controller to handle the freewheeling current. This rectifier circuit acts as a mediator that converts the inductive current into unidirectional current, eliminating the need for external freewheel diodes and their associated power losses.
2Reliability
If freewheel diodes are coupled in forward direction, then power conversion is enabled, but continuous power supply occurs even when converter does not operate
Solution Approach 1:
The patent makes the power supply path dynamic by using controllable switching elements (MOSFETs) instead of fixed freewheel diodes. The switching controller can dynamically control the on/off state of these switches, enabling true shutdown capability where power flow is completely blocked when not in use, eliminating continuous power consumption during standby.
Solution Approach 2:
The patent extracts the one-way current conducting property from the freewheel diode and replaces it with controllable switching elements. This allows the system to take out the diode's inherent limitation (inability to block reverse current) and replace it with actively controlled switches that can fully interrupt power flow during shutdown.
3Device complexity
If external freewheel diodes are used, then converter operation is achieved, but overall size and weight increase
Solution Approach 1:
The patent merges the freewheel diode function with the switching controller by integrating a rectifier circuit inside the switching controller. This eliminates the need for external freewheel diodes, reducing both power consumption (no 0.4-0.7V voltage drop) and device size/weight, while maintaining the power conversion function.
Solution Approach 2:
The switching controller is designed to perform multiple functions: primary switching control, rectification of inductive current, and freewheeling current management. By making the switching controller universal and multi-functional, external freewheel diodes become unnecessary, reducing overall component count and weight.
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 enables a compact, low-power DC-DC converter that can be fully shut down, reducing power consumption and extending the lifespan of organic light emitting displays by eliminating continuous power supply when not in use.
Implementation Method 1
a first inductor L11 electrically coupled to the power supplier 110
Implementation Method 2
a first switch M11 electrically coupled to the first inductor L11
Data Source
Figure 1
Figure 2a~2b
Figure 3~4
AI summary
An organic light emitting display having a DC-DC converter with freewheel diodes replaced by switches integrated into a switching controller. This way, power consumption is reduced by truly shutting down a current path when the DC-DC converter does not operate, and the size and weight of the DC-DC converter may be reduced. One embodiment of the DC-DC converter has a boost converter with a first switch coupled to a power supplier and a second switch, functioning as a freewheel diode, coupled to an organic light emitting display panel, and an inverter with a third switch coupled to the power supplier and a fourth switch, functioning as a freewheel diode, coupled to the organic light emitting display panel. A switching controller is coupled to the boost converter and the inverter. The second and fourth switches, which function as the freewheel diodes, are integrated into the switching controller.