Display Buffer Circuit With Compensation Current for Faster Slew Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face challenges in achieving a high slew rate for buffer circuits while maintaining low power consumption, especially when driven at lower voltages.
Innovation Solution
A buffer circuit design that includes an operational amplifier and a slew rate compensating circuit, which generates a compensation current proportional to the voltage difference between the input and output voltages to improve the slew rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the DDI is driven at a lower driving voltage to reduce power consumption, then power consumption is reduced, but the slew rate in the buffer circuit becomes slower
Solution Approach 1:
The slew rate compensating circuit performs preliminary action by generating compensation current in advance based on the voltage difference between input and output. This compensation current is prepared and applied proactively to counteract the slow transition caused by low driving voltage, thereby maintaining high slew rate without increasing power consumption.
Solution Approach 2:
The compensation current acts as an intermediary element that mediates between the low driving voltage condition and the required high slew rate performance. By introducing this intermediate compensation mechanism, the system achieves fast transition without directly increasing the main driving voltage, thus resolving the contradiction between power consumption and slew rate.
2Productivity
If a higher display frame rate is required to improve user experience, then display performance is improved, but the slew rate of the buffer circuit needs to be increased which may increase power consumption
Solution Approach 1:
The slew rate compensating circuit applies partial action by providing compensation current only during the transition periods when slew rate enhancement is needed, rather than continuously. The compensation is applied selectively based on the voltage difference detection, enabling high frame rate support without sustained excessive power consumption.
3Use of energy by moving object
If the buffer circuit operates with small voltage difference between input and output voltage, then power consumption is reduced, but the available compensation current is limited
Solution Approach 1:
The circuit changes the parameter of compensation current generation by using the voltage difference itself as the driving parameter for current generation. The slew rate compensating circuit converts the small voltage difference into a proportional compensation current through its internal circuitry, enabling effective compensation without requiring large voltage swings that would increase power consumption.
Data Source
AI summary
According to an embodiment, a buffer circuit includes an operational amplifier configured to output an output voltage based on voltages of a first output node and a second output node which vary in response to an input voltage of the operational amplifier, and a slew rate compensating circuit configured to receive the input voltage and the output voltage, generate a compensation current which is proportional to a voltage difference between the input voltage and the output voltage, and supply the compensation current to the first output node or the second output node.