Current Driver Segmentation for Micro-LED Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional current driving configurations for micro-LED arrays face challenges in reducing dynamic power consumption and coupling back noise, especially when trying to achieve finer pixel pitches, due to large turn-on resistance and restricted design flexibility.
Innovation Solution
A current driving digital pixel apparatus is designed with a low voltage first switching device and a medium voltage current mirror device, where the current driver is located outside the digital pixel cell, allowing for reduced dynamic power consumption and noise, and enabling more compact and flexible design to achieve finer pitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a medium voltage switching device is used in the conventional one-to-one configuration, then the micro-LED can be driven, but the turn-on resistance is large and dynamic current consumption is large
Solution Approach 1:
The current driver is segmented into two functional parts: a low voltage switching device for signal control and a medium voltage current mirror device for current regulation. This segmentation allows each component to operate in its optimal voltage range, reducing the turn-on resistance and dynamic current consumption of the switching device while maintaining proper driving capability for the micro-LED
Solution Approach 2:
The low voltage switching device acts as an intermediary between the control signal and the medium voltage current mirror device. It converts the control signal into a form that can efficiently drive the current mirror, reducing the direct burden on the switching device and thereby lowering its dynamic current consumption and turn-on resistance
2Adaptability or versatility
If the conventional one-to-one configuration is used for current drivers, then each micro-LED can be individually driven, but the available area in the circuit is restricted and flexibility in designing current drivers is limited
Solution Approach 1:
The current driver design using low voltage switching devices combined with medium voltage current mirror devices creates a universal interface that can control multiple micro-LEDs. This multi-functional approach allows a single driver circuit to serve multiple LEDs, increasing design flexibility and reducing the area required per LED while maintaining individual control capability
3Object-affected harmful factors
If medium voltage switching devices are used, then the micro-LED array can be driven, but coupling back noise is generated
Solution Approach 1:
The circuit employs different voltage levels in different locations: low voltage for the switching device (reducing noise generation) and medium voltage for the current mirror device (maintaining driving capability). This local differentiation of voltage quality reduces coupling back noise at the switching node while preserving the necessary driving power for the micro-LED
Data Source
AI summary
A current driving digital pixel apparatus including a power rail, a common rail, a micro light emitting device, and a current driver is provided. The power rail is configured to supply a source current. The micro light emitting device is electrically coupled to the common rail. The current driver includes a first switching device electrically coupled to the power rail and a current mirror device electrically coupled between the first switching device and the micro light emitting device. The current mirror device receives the source current from the power rail through the first switching device and supplies a current to the micro light emitting device. The first switching device is a low voltage device and the current mirror device is a medium voltage device.