VCOM Generator Circuit Using Reduced Supply Rails for Lower Display Power
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Solution Overview
Problem
Existing driver circuitry for electronic visual displays, such as LCDs, faces challenges in reducing power consumption and minimizing flickering and image retention issues, which affect performance and longevity.
Innovation Solution
A VCOM generator circuit with reduced supply rails, utilizing operational amplifiers with three or four supply rails (AVDD, GND, VP, and VN) to optimize power usage, where VP is less than AVDD and VN is higher than ground, allowing for dynamic selection of supply rails based on output needs, reducing power consumption and heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional VCOM circuit uses standard supply rails (AVDD and GND), then the circuit can provide sufficient voltage range for display operation, but power consumption is high
Solution Approach 1:
The supply voltage range is segmented into multiple intermediate rails (VP and VN) between AVDD and GND. The VCOM amplifier can selectively use different supply rails based on the required output voltage range, thereby reducing power consumption and heat generation by avoiding unnecessary voltage headroom.
Solution Approach 2:
The patent changes the supply voltage parameters by introducing intermediate rails VP and VN. This allows dynamic adjustment of the amplifier's supply voltage to match the actual output requirements, reducing power consumption while maintaining the ability to drive the display panel across its full operating range.
2Use of energy by moving object
If VCOM amplifier uses reduced supply rails to save power, then power consumption decreases, but the ability to drive full voltage range may be limited
Solution Approach 1:
The VCOM amplifier is designed with dynamic supply rail selection capability. It can adaptively choose from multiple supply rails (AVDD, VP, VN, GND) based on the required output voltage range, thereby maintaining full adaptability while reducing power consumption during normal operation.
Solution Approach 2:
The amplifier is designed to be multi-functional by supporting operation with different supply rail configurations. It can operate with full voltage range when needed (using AVDD and GND) or switch to reduced voltage modes (using VP and/or VN) for power-saving operations, making it universally adaptable to different operating conditions.
3Use of energy by moving object
If VCOM circuit uses more supply rails (3 or 4 rails), then power consumption is reduced through selective operation, but circuit complexity increases
Solution Approach 1:
The patent merges multiple supply rail control functions into a unified VCOM amplifier design. By integrating the ability to select from multiple supply rails within a single amplifier architecture, it reduces overall system complexity compared to using separate circuits for different voltage ranges.
Data Source
AI summary
A VCOM generator circuit generates a VCOM signal for an electronic display. The VCOM circuit includes an operational amplifier having reduced supply rails. In an implementation, the VCOM circuit has at least three supply rails, AVDD, ground or GND, and VP or VN, or both. VP is less than AVDD and greater than VN. VN is higher than ground and below VP. The VCOM circuit with reduced voltage supply rails for VP and VN reduces power consumption of the VCOM op amps. By reducing power consumption, this also reduces the surface temperature of the integrated circuit.