DC-DC Converter Pulse Counting for Low-Power Short Detection
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Solution Overview
Problem
Existing DC-DC converters cannot determine short circuit defects in display panels during low-power mode due to the non-operation of current sensors in this mode, leading to potential power consumption issues and reduced functionality.
Innovation Solution
A DC-DC converter design that includes a switcher and controller, which generates an output voltage based on an external input voltage and uses pulse width modulation to count the number of switching events in low-power mode, determining a short circuit defect when the count value exceeds a reference count value, and switches to pulse width modulation mode for further defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the DC-DC converter operates in low-power mode using pulse skip mode, then power consumption is reduced, but the ability to detect short circuit defects is lost
Solution Approach 1:
The patent introduces a pulse counter as an intermediary element that indirectly detects short circuit defects by counting the number of pulse width modulation signals during pulse skip mode operation. Instead of directly measuring current (which would require active current sensor operation), the system uses the pulse count as a proxy indicator - when the display panel has a short circuit defect, the driving current increases, causing the DC-DC converter to generate more pulses to maintain the required output voltage, and this increased pulse frequency is captured by the counter.
2Reliability
If the current sensor operates continuously to detect short circuit defects, then defect detection capability is maintained, but power consumption increases
Solution Approach 1:
The patent implements periodic action by activating the current sensor only when needed - specifically, when transitioning from pulse skip mode to pulse width modulation mode, or when a short circuit defect is suspected. During normal pulse skip mode operation, the current sensor remains inactive, and the system relies on the pulse counter for indirect monitoring. This periodic activation strategy maintains defect detection capability while minimizing power consumption associated with the current sensor.
3Reliability
If the DC-DC converter uses pulse width modulation mode for defect detection, then short circuit defect can be determined, but power consumption increases
Solution Approach 1:
The patent applies dynamics by making the operating mode flexible and adaptive - the system dynamically switches between pulse skip mode (low power consumption) and pulse width modulation mode (higher power consumption but with direct defect detection capability). The controller monitors the pulse count and other parameters, and when a short circuit defect is detected or suspected, it transitions to pulse width modulation mode for accurate detection. This dynamic mode switching allows the system to optimize between power consumption and detection accuracy based on actual operating conditions.
Data Source
AI summary
A direct current to direct current converter includes a switcher which generates an output voltage based on an external input voltage, and a controller which controls the switcher based on a pulse width modulation signal. The controller counts the number of switching of the pulse width modulation signal in a pulse skip mode of a low-power mode, generate a count value, and determines a short circuit defect when the count value is equal to or greater than a reference count value.