Display Driver Overcurrent Protection via Power Line Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices face damage due to failures in the connection between light emitting elements and driving power sources, causing driving current to flow through initialization power sources instead of the light emitting elements, potentially damaging the driver.
Innovation Solution
A display device with a power supply system that includes first, second, and third power lines, where the driver measures a sensing voltage on the second power line and limits or interrupts the third power voltage when it is out of a reference range, using a comparator and control signal generator to prevent overcurrent and protect the driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the driver continuously supplies initialization voltage to initialize the light emitting element, then the light emitting element can be properly initialized to improve display performance, but the driver may be damaged by overcurrent when there is a connection failure between the light emitting element and driving power sources
Solution Approach 1:
The driver measures the second power voltage through a routing line and uses this feedback information to determine whether to supply the third power voltage. When the second power voltage is abnormal (outside reference range), the driver stops supplying the third power voltage, preventing overcurrent damage while maintaining initialization functionality when conditions are normal
Solution Approach 2:
The driver performs preliminary voltage measurement and verification before supplying the third power voltage to the display panel. By checking whether the second power voltage is within the reference range in advance, the driver prevents harmful overcurrent from occurring before it can damage the circuit
2Object-affected harmful factors
If the driver measures and monitors the second power voltage to prevent overcurrent, then the driver can be protected from damage, but the device complexity increases due to additional sensing circuits and control logic
Solution Approach 1:
The driver performs multiple functions using the same circuit components: it supplies the third power voltage for initialization, measures the second power voltage through an existing routing line, compares the measured voltage against reference values, and controls the power supply based on the comparison results. This multi-functionality reduces the need for separate dedicated protection circuits
Solution Approach 2:
The routing line serves as an intermediary that allows the driver to measure the second power voltage without requiring a separate sensing path. The routing line already exists for power delivery, and the driver utilizes it for both power supply and voltage measurement purposes, simplifying the overall circuit architecture
Data Source
AI summary
A display device includes: a display panel including a pixel electrically connected to each of a data line, a first power line, a second power line, and a third power line; a power supply to provide a first power voltage to the first power line, and a second power voltage to the second power line; and a driver to provide a data voltage to the data line, and a third power voltage to the third power line. The driver is to determine whether a sensing voltage measured at the second power line is out of a reference range, and to limit the supply of the third power voltage when the sensing voltage is out of the reference range.