GOA Short-Circuit Protection Circuit for LCD Panels
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Solution Overview
Problem
In Gate Driver on Array (GOA) liquid crystal panels, short-circuits often occur due to manufacturing process factors, leading to excessive CLK_OUT current and potential panel damage or fire, as the plastic frame may not be tightly configured, causing the CLK_OUT output of the level shifter to be short-circuited.
Innovation Solution
A short-circuit protection circuit is implemented, comprising a power module, first and second booster modules, a feedback module, and a control module, where the control module detects excessive feedback current and cuts off the PWM signal to prevent excessive output current, employing diodes, capacitors, and a transistor to manage voltage and current, thereby entering a short-circuit protection mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the CLK_OUT output of the level shifter is used without protection, then the liquid crystal panel can operate normally, but the output current may become excessive and cause short-circuit damage or fire
Solution Approach 1:
The feedback module continuously monitors the output current before excessive current can cause damage. The control module is pre-configured to detect abnormal current conditions and automatically cut off the PWM signal, preventing short-circuit damage before it occurs.
Solution Approach 2:
The feedback module extracts a feedback current from the current flowing from the first to the second booster module and provides a feedback signal to the control module. When the feedback current exceeds a current threshold, the control module cuts off the PWM signal, forming a closed-loop current protection mechanism.
2Reliability
If a feedback module with current threshold detection is added, then excessive current can be detected and protected against, but the circuit complexity increases
Solution Approach 1:
The feedback module is integrated into the existing power supply circuit between the first and second booster modules. The current detection function is combined with the existing current path, allowing the control module to monitor output current without requiring a completely separate detection circuit.
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 effectively prevents the liquid crystal panel from burning due to short-circuit by reducing excessive output current, enhancing the reliability and safety of the GOA liquid crystal panels.
Implementation Method 1
The feedback module contains a transistor having a base, an emitter, and a collector. The base is electrically connected to the feedback signal input terminal. The emitter is electrically connected to the first booster module. The collector is electrically connected to the second booster module.
Implementation Method 2
The first capacitor has a first terminal electrically connected to the cathode of the first diode and a second terminal electrically connected to the PWM signal output terminal. The second capacitor has a first terminal electrically connected to the cathode of the second diode and a second terminal electrically connected to ground.
Data Source
AI summary
The short-circuit protection circuit for a Gate Driver on Array (GOA) liquid crystal panel contains a power module, a first booster module, a feedback module, and a second booster module series-connected in the this order. A control module is electrically connected to the first booster, feedback, and second booster modules. The power module provides a power voltage. The control module provides a pulse width modulation (PWM) signal so as to control the first and second booster modules to transform the power voltage into driving voltage. The feedback module extracts a feedback current from a current flowing from the first to the second booster module and provides a feedback signal to the control module. When the feedback current exceeds a current threshold, the control module cuts off the PWM signal output so as to achieve short-circuit protection. A liquid crystal panel incorporating the above short-circuit protection circuit is also provided.