Gate Driver Overcurrent Detection Using Delayed Signal Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display apparatuses, abnormal display signals can cause overcurrent issues in gate driver circuits, leading to damage and reduced service life due to abnormal scanning and potential polarization or drift of liquid crystals or thin film transistors.
Innovation Solution
An overcurrent protection circuit is implemented, comprising a sampling sub-circuit, delay determination sub-circuit, and counting control sub-circuit, which continuously detects gate input signals, identifies overcurrent conditions, and outputs control signals to cut off power supply to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the timing controller continuously monitors gate input signals to detect overcurrent conditions, then the reliability of the display panel is improved, but the device complexity increases due to additional protection circuits
Solution Approach 1:
The protection circuit performs preliminary detection of gate input signal voltage levels before overcurrent damage occurs. The sampling sub-circuit continuously monitors voltage levels, and the delay determination sub-circuit prepares control signals in advance when abnormal voltage levels are detected, enabling preventive action before actual overcurrent damage happens to the display panel
Solution Approach 2:
The protection circuit introduces intermediary components between the timing controller and the display panel. The sampling sub-circuit, delay determination sub-circuit, and counting control sub-circuit act as intermediaries that monitor and control the gate input signals, preventing direct overcurrent damage to the display panel while adding controlled complexity to the system architecture
2Measurement precision
If the protection circuit delays the control signal to avoid false triggering, then the measurement precision is improved, but the response time increases
Solution Approach 1:
The protection circuit uses periodic sampling of gate input signals at predetermined time intervals. The sampling sub-circuit periodically acquires voltage levels, and the counting control sub-circuit uses a preset number of sampling periods to determine whether to trigger protection. This periodic approach filters out transient noise while maintaining responsive protection timing
Solution Approach 2:
The delay determination sub-circuit performs preliminary processing of sampled signals by comparing voltage levels against reference values and generating control signals in advance. This preliminary action with predetermined thresholds and delay timing ensures accurate detection of genuine overcurrent conditions while filtering false positives, balancing precision with response time
3Reliability
If the counting control sub-circuit uses a preset number of sampling periods to confirm overcurrent, then the reliability of protection activation is improved, but the loss of time increases due to multiple sampling cycles
Solution Approach 1:
The counting control sub-circuit uses a preset number of sampling periods that provides sufficient confirmation without excessive delay. This partial action approach uses just enough sampling cycles to reliably distinguish genuine overcurrent from noise, avoiding both premature activation and excessive delay in protection response
Data Source
AI summary
An overcurrent protection circuit includes: a sampling sub-circuit configured to acquire gate input signals, select a gate input signal with a voltage value greater than a first preset voltage value as a sample gate input signal, generate a first control signal according to the sample gate input signal, and output the first control signal; a delay determination sub-circuit configured to receive the first control signal, delay the first control signal for a first preset time, determine whether a voltage value of the first control signal after delay is less than a voltage value of the first control signal before the delay, and if not, output a counting signal; and a counting control sub-circuit configured to receive the counting signal, perform counting according to the counting signal, and if a counted number reaches a preset number, output a second control signal.