DC Boost Circuit Voltage Drop Compensation for AMOLED Displays
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Solution Overview
Problem
Conventional DC boost circuits for AMOLED display devices suffer from voltage drops due to impedance between the circuit and the load, leading to unstable output voltage, which affects the brightness and display quality of OLED displays as different load currents are required for varying frames.
Innovation Solution
A DC boost circuit comprising an inductor, diode, capacitor, FET, voltage conversion unit, voltage drop detection module, and control module, which adjusts the conduction interval of the FET to compensate for voltage drops by using a voltage conversion unit, voltage drop detection module, and control module to maintain a stable output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional DC boost circuit is used to provide positive power voltage to the AMOLED pixel driving circuit, then voltage boost is achieved, but the output voltage suffers voltage drop due to impedance between the DC boost circuit and the load
Solution Approach 1:
The patent implements a feedback mechanism where the control module continuously monitors the output voltage and adjusts the FET's conduction interval accordingly. When voltage drop is detected due to load current, the control module increases the conduction interval to compensate and maintain stable output voltage, thereby resolving the contradiction between achieving voltage boost and maintaining voltage stability.
Solution Approach 2:
The patent makes the FET's conduction interval dynamic rather than fixed. The control module adjusts the conduction interval in real-time based on the detected voltage drop and load conditions, allowing the DC boost circuit to adapt to varying load currents and maintain stable output voltage, thus resolving the stability issue.
2Reliability
If the conduction interval of the FET is increased to compensate for voltage drop, then output voltage stability is improved, but the circuit complexity increases due to additional control mechanisms
Solution Approach 1:
The control module uses a feedback loop that monitors output voltage and automatically adjusts the FET's conduction interval. This closed-loop control mechanism maintains voltage stability without requiring complex manual intervention or additional hardware, as the feedback system self-regulates based on detected voltage conditions.
Solution Approach 2:
The DC boost circuit performs self-regulation through the control module, which automatically detects voltage drop and adjusts the conduction interval without external intervention. The system serves itself by monitoring its own output and making necessary adjustments, thereby maintaining stability without adding excessive complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution ensures a stable output voltage level by compensating for voltage drops caused by impedance, enhancing the display quality of OLED displays by maintaining consistent brightness across different load conditions.
Implementation Method 1
When the DC boost circuit operates, the FET Q10 is conducted by the control signal PWM and the input voltage Vin charges the inductor L10 and the capacitor C10. When the FET Q10 is cut off by the control signal PWM, the inductor L10 charges the capacitor C10.
Implementation Method 2
The capacitor C10 has a first terminal electrically connected to the cathode of the diode D10, and a second terminal to ground.
Data Source
AI summary
The present invention teaches a DC boost circuit and method. The circuit includes an inductor, a diode, a first capacitor, a first FET, a first voltage conversion unit, a voltage drop detection module, a reference voltage adjustment module, and a control module. After a load is connected, the voltage drop detection module obtains a current flowing through the diode and outputs a corresponding second voltage to the reference voltage adjustment module, causing an output voltage from the reference voltage adjustment module greater than an original reference voltage. The control module controls the first FET to increase a ratio of its conduction interval to its cutoff interval in a cycle of conduction and cutoff, thereby increasing the output voltage to compensate the voltage drop resulted from the impedance between the DC boost circuit and the load. The output voltage is therefore ensured to have a stable level.