Relationship Between LED Display Refresh Rate and Driver ICs

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The refresh rate of an LED display is closely related to the performance of its driver ICs. Through hardware design and technological innovation, driver ICs directly determine the maximum refresh rate and stability of the display. The following analysis expands from three levels: technical principles, core mechanisms, and practical applications.

The refresh rate refers to the number of times the display updates the image per second, measured in Hz. Driver ICs control the lighting timing and current distribution of LED pixels to achieve dynamic image refresh. Their core role is reflected in two aspects:

Data Transmission Efficiency: Driver ICs need to complete data reception, decoding, and output within an extremely short time. For example, high-end chips (such as Macroblock's MBI5152) support high-speed shift clocks (15-25 MHz and above), enabling grayscale data transmission for a row of pixels within microseconds. If the chip's data processing speed is insufficient, it can lead to a decreased refresh rate or screen tearing.

Row Scan Control:Under non-static scanning (e.g., 1/16 scan), the driver IC needs to light up pixels row by row. Taking 1/16 scan as an example, if the total refresh rate is 3840Hz, the refresh interval for each row is only 6.5μs. The chip needs to use row scan multiplication technology (e.g., the 16x multiplication of Sunmoon's SM16380SF) to shorten the row switching time, thereby increasing the overall refresh rate.

Cache and Multiplication Technology Built-in SRAM Cache: Chips like the SM16380SF have built-in 32K SRAM, which can pre-store multiple rows of grayscale data, reducing data transmission wait times.

PWM Multiplication:By increasing the PWM (Pulse Width Modulation) frequency, more refresh cycles can be completed in the same time. For instance, TBSilicon's Hybrid PWM+PAM chips increase the PWM frequency to 64KHz, achieving a 1 grayscale 240Hz refresh rate, completely eliminating low grayscale flicker.

Multi-channel Output: 16-channel chips (like SM16169S) reduce the number of chips required by half compared to 8-channel chips, lowering wiring complexity and improving data transmission efficiency.

Dynamic Row Scan Compensation:For high scan numbers (e.g., 1/64 scan), chips use features like pre-charge and shadow elimination (e.g., MBI515X series) to eliminate the effects of parasitic capacitance, ensuring uniform refresh time for each row.

Balance Between Grayscale and Refresh Rate: In traditional PWM driving, a high refresh rate compresses the grayscale time, leading to poor low grayscale performance. New chips solve this contradiction through hybrid driving technology (like Hybrid PWM+PAM):

PWM controls the dynamic range of high grayscales, while PAM (Pulse Amplitude Modulation) adjusts the brightness of low grayscales, achieving a 1200Hz refresh rate at 1 nit brightness while maintaining 24-bit grayscale accuracy.

Professional Filming Scenarios (e.g., virtual studios, sports events) require refresh rates above 3840Hz to prevent high-speed cameras from capturing scan lines. Refresh rates of tens of thousands of Hz (e.g., 15,360Hz) can meet the shooting requirements with shutter speeds of 1/10,000 second, commonly used in cinematic virtual production.

A refresh rate of ≥3840Hz is recommended to resist ambient light interference. Driver ICs need to support dynamic power saving (like the intelligent power consumption adjustment of SM16380SF) to reduce heat generation and energy consumption under high refresh rates.

Typically use 1/16 to 1/64 scan designs, requiring chips to enhance the refresh rate through row scan multiplication and cache. For example, Xintao's CFD555 achieves a 3840Hz refresh rate under 64 scan, meeting the fineness requirements for close viewing.

With advancements in chip technology, refresh rates are progressing from 3840Hz towards tens of thousands of Hz and beyond.

Technological Breakthroughs: New chips are improving switching speeds through Gallium Nitride (GaN) processes, combined with AI algorithms to optimize timing. It is estimated that by 2026, refresh rates of 100,000 Hz level could be achieved.

Application Expansion:Ten-thousand Hz level refresh rates will drive development in emerging fields like AR/VR and medical imaging. For example, surgical microscopes may require 100,000 Hz level refresh rates to display dynamic details of cells.

Driver ICs are the core engine of the LED display refresh rate. Their data transmission rate, row scan control capability, and grayscale optimization technology directly determine the upper limit of the refresh rate. From the early general-purpose chips like the 74HC595 to today's intelligent Hybrid PWM+PAM chips, technological iteration has always revolved around "higher refresh rate, lower power consumption, and better image quality." In the future, with breakthroughs in materials science and algorithms, driver ICs will further push physical limits, bringing new experiences to LED displays.