Backlight Control Circuit Undervoltage Protection Mechanism
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Solution Overview
Problem
The existing backlight driving circuits face damage due to high currents when power supply is stopped, as the voltage drop is gradual, causing continuous operation and increased current through inductors and diodes.
Innovation Solution
A backlight control circuit with an undervoltage protection circuit that outputs a closing control signal when the voltage falls below a threshold, stopping the backlight driving circuit from working, thereby preventing high currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the backlight driving circuit continues to operate after power supply is stopped, then the voltage drop time is extended, but high currents damage the inductors and diodes
Solution Approach 1:
The undervoltage protection circuit detects the power supply voltage in advance and outputs a closing control signal before the voltage drops to a dangerous level. This preliminary action prevents the backlight driving circuit from operating under undervoltage conditions that would cause high currents and component damage.
Solution Approach 2:
The undervoltage protection circuit continuously monitors the power supply voltage and provides feedback through the closing control signal. When the voltage falls below the threshold, the feedback signal immediately shuts down the backlight driving circuit, preventing harmful high currents while allowing normal operation when voltage is sufficient.
2Reliability
If the undervoltage protection circuit is added to monitor voltage, then component protection is improved, but circuit complexity increases
Solution Approach 1:
The undervoltage protection circuit acts as an intermediary between the power supply and the backlight driving circuit. It monitors the power supply voltage and controls the backlight driving circuit through the closing control signal, providing protection without requiring modification to the existing backlight driving circuit components.
Solution Approach 2:
The protection function is segmented from the main backlight driving circuit into a separate undervoltage protection circuit. This modular approach allows the protection function to be added independently, maintaining the original circuit design while providing reliable component protection.
Data Source
AI summary
Embodiments of the present disclosure provide a backlight control circuit, a method for driving the same, a backlight module and a display apparatus. The backlight control circuit includes: an undervoltage protection circuit, electrically connected with a power supply voltage input end and a ground, and configured to output a closing control signal through an output end of the undervoltage protection circuit according to a voltage at the power supply voltage input end and an undervoltage threshold value; and a backlight driving circuit, electrically connected with a voltage supply end, a backlight driving output end and the output end of the undervoltage protection circuit separately, and configured to enable a port of the backlight driving circuit when receiving an enabling control signal for processing a voltage at the voltage supply end and outputting the processed voltage to the backlight driving output end, and stop working when receiving the closing control signal.