Gate Drive Circuit Voltage Holding for Pull-Up Node Stability
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Solution Overview
Problem
The existing gate drive circuits face instability in the potential of pull-up nodes during the touch stage due to leakage of charge capacity, making it difficult to maintain a stable potential.
Innovation Solution
A gate drive circuit comprising cascaded gate drive units with a pull-up transistor, a touch transistor, and a voltage holding circuit, where the voltage holding circuit maintains the potential of the pull-up node by continuously injecting high potential signals during the touch stage, and sharing the touch line with the control end of the voltage holding circuit to reduce wire count and border space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate drive circuit operates during the touch stage without additional voltage holding components, then the circuit complexity is reduced, but the potential of the pull-up node becomes unstable due to charge leakage
Solution Approach 1:
The voltage holding circuit is activated before the touch stage begins (controlled by the touch signal TP going high) to pre-charge and maintain the pull-up node Q(N) at high potential. This preliminary action ensures that when the touch stage starts, the pull-up node is already stabilized and can withstand charge leakage throughout the touch operation.
Solution Approach 2:
The voltage holding circuit acts as an intermediary component between the high potential line VGH and the pull-up node Q(N). It mediates the potential maintenance by continuously supplying charge to the pull-up node through transistor T13, isolating the pull-up node from the direct influence of charge leakage while maintaining stable high potential.
2Ease of operation
If separate control lines are used for the touch transistor and voltage holding circuit, then the control precision is improved, but the wire count and border space increase
Solution Approach 1:
The control inputs of the touch transistor Ttp and the voltage holding circuit (transistor T13) are merged by connecting their gates to the same touch line. This merging reduces the wire count and border space while maintaining precise control, as the touch signal TP simultaneously controls both components to work together in coordinating fashion.
Solution Approach 2:
The touch line serves multiple functions: it controls the touch transistor Ttp for touch signal transmission and simultaneously controls the voltage holding circuit (transistor T13) for pull-up node potential maintenance. This multi-functionality eliminates the need for separate control lines while preserving control precision through coordinated operation.
Data Source
AI summary
Embodiments of the present disclosure are directed to a gate drive circuit and a display panel. The gate drive circuit includes a plurality of cascaded gate drive units. The N-level gate drive unit includes a pull-up transistor, a touch transistor, and a voltage holding circuit. An input end of the voltage holding circuit is connected with a high potential line, a first control end of the voltage holding circuit is connected with a touch line, a second control end of the voltage holding circuit is connected with a pull-up node, and an output end of the voltage holding circuit is connected with the pull-up node. The display panel includes a common voltage line and the gate drive circuit mentioned above, thereby alleviating the technical problem of unstable potential of pull-up nodes during a touch stage.