Source Driver Circuit Area Reduction via Current Control
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Solution Overview
Problem
Existing source drivers for display apparatuses require large transistors to handle high voltages, increasing circuit area and power consumption due to the need for high-voltage components like voltage follower amplifiers, which hinders miniaturization and power efficiency.
Innovation Solution
A source driver configuration using a resistor with a controlled current source, where the current source is connected to the data line, allowing the voltage corresponding to the gradation value to be supplied, eliminating the need for high-voltage amplifiers and reducing circuit area and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-voltage transistors and amplifier circuits are used to drive data lines, then the display apparatus can operate at required voltage levels, but the circuit area increases and power consumption rises
Solution Approach 1:
The patent changes the voltage parameter from high voltage to low voltage operation by using a current source controlled by low-voltage digital signals. The current source converts these low-voltage signals into appropriate current levels that, when passed through a resistor, generate the required high voltage on the data line without requiring high-voltage transistors in the signal path.
Solution Approach 2:
The patent replaces the traditional voltage amplification mechanism (mechanical/electrical system using high-voltage transistors and amplifier circuits) with a current-controlled mechanism. Instead of using voltage follower amplifiers that require large high-voltage transistors, the invention uses a current source that is controlled by low-voltage digital signals, substituting the voltage amplification approach with a current modulation approach.
2Reliability
If transistors with large element sizes are used to handle high voltages, then the circuit can withstand required voltage levels, but the circuit area increases
Solution Approach 1:
The patent changes the operating voltage parameter from high voltage to low voltage for the transistors in the signal path. By using a current source controlled by low-voltage digital signals, the transistors only need to withstand low voltage levels, allowing the use of smaller element sizes and reducing the overall circuit area while maintaining the ability to generate high voltages on the data line through the resistor.
Solution Approach 2:
The patent introduces a resistor as an intermediary element between the current source and the data line. This resistor converts the low-voltage, high-current signal from the current source into the required high-voltage signal on the data line, allowing the transistors to operate at low voltage levels while still achieving high-voltage output.
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
This configuration reduces the circuit area and power consumption by controlling current with low voltage, enabling smaller and more energy-efficient display apparatuses.
Implementation Method 1
a resistor having an end to which a predetermined power supply voltage is applied, and a current source that is connected to another end of the resistor, the amount of current of the current source being controlled according to the gradation value of the video signal, the voltage corresponding to the gradation value of the video signal being supplied from the other end of the resistor
Data Source
AI summary
Provided is a source driver that is used for supplying a voltage corresponding to a gradation value of a video signal to a data line of a display unit, the source driver including: a resistor having an end to which a predetermined power supply voltage is applied; and a current source that is connected to another end of the resistor, the amount of current of the current source being controlled according to the gradation value of the video signal, the voltage corresponding to the gradation value of the video signal being supplied from the other end of the resistor.