Voltage Providing Circuit Power Sequence Controller
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Solution Overview
Problem
Digital driving methods for electroluminescent displays face image quality degradation due to timing deviations in power supply voltages and ohmic drops, which are difficult to manage with complex IC structures, especially in large and high-resolution displays.
Innovation Solution
A voltage providing circuit with a power sequence controller that efficiently manages power sequences by enabling and disabling voltage regulators based on feedback signals and logic operations, preventing flickering and enhancing image quality without adding complex hardware or software.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex IC structure is used to manage power supply voltages, then power sequence control can be achieved, but device complexity increases
Solution Approach 1:
The power sequence controller is divided into multiple independent logic units: a first logic unit that generates the first enable signal based on the ready signal and data voltage, and a second logic unit that generates the second enable signal based on the ready signal and first power supply voltage. This segmentation allows each unit to perform a specific function independently, achieving reliable power sequence control without requiring a complex monolithic IC structure.
Solution Approach 2:
The controller activates voltage regulators in a predetermined sequence based on the ready signal. Before the display panel operates, the first voltage regulator is activated to generate the first power supply voltage, followed by the second voltage regulator generating the data voltage. This preliminary action ensures proper power sequencing without complex real-time control logic.
2Speed
If voltage regulators are activated simultaneously, then power supply is faster, but timing deviation degrades image quality
Solution Approach 1:
The system activates the first voltage regulator before the second voltage regulator based on the ready signal timing. This preliminary activation sequence ensures that the first power supply voltage is established before the data voltage, preventing timing deviations that would degrade image quality while maintaining efficient power supply speed.
Solution Approach 2:
The enable signals for the voltage regulators are dynamically controlled based on real-time voltage levels and the ready signal state. The first enable signal is activated when the ready signal is high and data voltage exceeds a threshold, while the second enable signal is activated when the ready signal is high and first power supply voltage exceeds a threshold. This dynamic control achieves precise timing without simultaneous activation.
3Device complexity
If power sequence control is simplified, then device complexity is reduced, but flickering may occur
Solution Approach 1:
The power sequence controller uses feedback from voltage level comparisons to control the enable signals. The first enable signal is generated based on feedback from the data voltage level and ready signal, while the second enable signal is generated based on feedback from the first power supply voltage level and ready signal. This feedback mechanism ensures proper power sequencing and prevents flickering without adding complex control circuitry.
Solution Approach 2:
The voltage regulators self-regulate their activation and deactivation based on the enable signals generated by the logic units. When the ready signal changes state or voltage thresholds are crossed, the logic units automatically adjust the enable signals, causing the voltage regulators to turn on or off as needed. This self-service mechanism maintains image stability without requiring complex external control.
Data Source
AI summary
A display device includes a data driver configured to generate a data signal based on a data voltage; a display panel configured to be driven based on a first power supply voltage and the data signal; a timing controller configured to control operations of the data driver and the display panel and configured to generate a ready signal indicating a power supply timing; a first voltage regulator configured to generate the first power supply voltage based on a first input voltage and a first enable signal; a second voltage regulator configured to generate the data voltage based on the first input voltage and a second enable signal; and a power sequence controller configured to generate the first enable signal based on the ready signal and the data voltage and configured to generate the second enable signal based on the ready signal and the first power supply voltage.