Gate Driving Circuit With Separated Control Nodes for Threshold Stability
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Solution Overview
Problem
The threshold voltage shift in the inverting circuit of a gate driving circuit leads to improper operation, affecting the normal functioning of the gate driver and display apparatus due to high voltage levels at the control nodes.
Innovation Solution
The control node of the pull-up circuit and the control node of the inverting circuit are separated, with the maximum voltage of the inverting circuit's control node being less than that of the pull-up circuit, reducing positive bias temperature stress and threshold voltage shift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control node of the inverting circuit is connected to the pull-up circuit with high voltage levels, then the inverting circuit can operate with proper signal levels, but the threshold voltage of switching elements shifts due to positive bias temperature stress
Solution Approach 1:
The patent divides the control node functionality into separate nodes: a first control node for the pull-up circuit and a second control node for the inverting circuit. This segmentation isolates the high voltage stress from the inverting circuit's switching elements, preventing threshold voltage shift while maintaining proper signal levels through controlled voltage transmission.
Solution Approach 2:
The patent introduces an inverting control circuit as an intermediary between the pull-up circuit and the inverting circuit. This intermediary controls the voltage level at the second control node, ensuring that switching elements receive appropriate voltage levels without being exposed to the high voltage stress that would cause threshold voltage shift.
2Ease of operation
If high voltage levels are applied to the control node of the inverting circuit, then the inverting circuit can properly switch signals, but the lifetime of the circuit decreases due to threshold voltage shift
Solution Approach 1:
By segmenting the control node into separate first and second control nodes, the patent enables the inverting circuit to operate with proper voltage levels at the second control node while isolating it from the high voltage stress that would otherwise reduce circuit lifetime.
Solution Approach 2:
The patent applies different voltage characteristics to different parts of the control structure: the first control node handles high voltage levels for pull-up operation, while the second control node maintains lower voltage levels suitable for inverting circuit switching, optimizing both operation and lifetime.
3Stability of the object's composition
If the control nodes are separated with reduced voltage at the inverting circuit's control node, then threshold voltage shift is minimized, but the circuit complexity increases
Solution Approach 1:
The inverting control circuit serves multiple functions: it receives the carry signal, controls the voltage level at the second control node, and protects the inverting circuit from high voltage stress. This multi-functionality justifies the additional structural elements by consolidating control functions.
Solution Approach 2:
The inverting control circuit acts as a mediator that adds controlled complexity to manage the voltage levels between the pull-up circuit and inverting circuit, achieving threshold voltage stability while maintaining manageable circuit architecture.
Data Source
AI summary
A gate driving circuit includes: a first pull-up control circuit, a pull-up circuit, a pull-down circuit and an inverting circuit. The first pull-up control circuit applies a previous carry signal which is one of carry signals of previous stages to a first control node in response to the previous carry signal. The pull-up circuit outputs a gate clock signal as a gate output signal in response to a signal of the first control node. The pull-down circuit outputs a second low voltage as the gate output signal in response to a first next carry signal which is one of carry signals of next stages. The inverting circuit outputs one of a first signal and a first low voltage to a third control node in response to the first signal and a signal of a second control node.