Driving Display Innovation: 22nm Mobile Display Driver IC Makes Low Power the Norm

Introducing 22nm process technology for mobile display driver ICs

In 2024, discussion in the semiconductor industry tends to focus on the fierce competition to achieve the latest ultra-fine process. Even though 3nm process technology is relatively new to the market, it feels like both the industry and the public are already looking toward a 2nm future.

Against this backdrop, Samsung System LSI has designed and developed a display driver IC (DDI) for smartphones using a 22nm process, which has been in mass production over a year. Although 22nm might seem large in comparison to 2nm, it is an advanced node in the DDI industry. This is due to the wide variety of semiconductor types used in the market, with 28nm and 45nm process technology often being applied to products that do not require ultra-fine processes. It is in this context that Samsung has reestablished its role as a fast mover, as it is now the first in the industry to successfully design, develop and commercialize a mobile DDI (mDDI) using the 22nm process.

22nm mDDI is all about power efficiency and functionality

At the core of this progression to a 22nm process is the market’s push toward the reduction of power consumption, which continues to be a key consideration of DDI design. From the outset, Samsung System LSI researched and developed a 22nm process for mDDIs to achieve this goal. With the rising popularity of mobile functions like on-device AI, there is a need for power reduction of components that are not the application processor (AP). And since display screen power consumption is high, reducing their power draw is particularly valuable to the industry.

What’s more, this lower power consumption must be achieved while still meeting the market’s need for better-looking displays with high resolutions and high frame rates, which generally use more power. WQHD mobile displays now require a frame rate exceeding 165Hz, beyond 120Hz, while foldable displays require higher resolutions to achieve sufficient pixel density.  

There are even more considerations: existing image-quality functions, like compensation for OLED mura¹ and crosstalk² have become essential, and new functions like the under-panel camera and private mode are also being implemented. As a result, the circuit complexity of DDIs has increased along with the amount of data to be processed, which leads to further increased power usage.  

That mobile displays have evolved to this level of advanced functionality is excellent for the user, but it also means that power-reducing solutions for DDIs are more important than ever. And this is why System LSI’s 22nm process and power-saving design technologies are reaching the market at exactly the right time.  
 

Next-generation mDDI products based on leading 22nm research

As mentioned, 22nm process technology shrinks the logic process of the 28nm process that is typically  used to manufacture mDDIs for premium smartphones. Thanks to this finer node, it can reduce logic power by approximately 30% (1V to 0.8V) and the logic area by 10%.

System LSI was one of the first in the industry to start preliminary research on the 22nm process for mDDIs, which was started in 2021. The results of the research showed that in comparison to Samsung's equivalent-level ICs, the 22nm process led to an approximately 20% reduction in logic current. Following this, the qualification testing for 22nm ICs was successfully completed, allowing for a smooth transition to mass production of mDDIs.
 

Improved design, decreased power

In addition to the power-saving advantages of the 22nm process, System LSI has developed a low power design kit that achieves approximately 12% further power reduction. It minimizes clock toggle during circuit operation, which reduces dynamic current even when performing the same operations. This maximizes the effect of reduced logic currents along with the 22nm process.

Furthermore, through the comprehensive application of clock gating,³ System LSI is providing a low-power solution suitable for variable refresh rate (VRR), which changes the frame rate according to the state of display image. VRR allows the display to vary from 120Hz to 1Hz, and it has been confirmed that there is a logic power reduction of approximately 38% at 120Hz and about 45% at 1Hz, when compared to the predecessor manufactured using the 28nm process.
 

Market-proven progress in power efficiency

Samsung’s first mDDI to use the 22nm process confirmed the technology’s impressive power efficiency. Compared to its 28nm-based predecessor, the new model reduced logic power by 38%, based on the advantages of the finer process and the application of the low-power design kit. This led to a verified 16% reduction in IC power, which is equivalent to an extra hour of battery life.⁴ Building on that initial progress, the 22nm process has also been successfully mass-produced and applied to an mDDI for foldable devices. Both of these achievements are indications of a positive trajectory for the mDDI product lineup.

Looking to the future, Samsung System LSI will continue striving to be a fast adopter of advanced processes, and it will also aim to maintain its technological leadership in DDI products. This will be achieved by constantly enhancing the company’s design technology to meet the various demands of low-power products, with the ultimate goal of creating products and technologies that elevate user experiences.
 

* All images shown are provided for illustrative purposes only and may not be an exact representation of the product. All images are digitally edited, modified, or enhanced.

* All product specifications reflect internal test results and are subject to variations by user's system configurations. Actual performance may vary depending on use conditions an environment. 

_{¹⁾ The mura effect, also known as clouding, describes uneven displays caused by imperfect illumination of the screen.
²⁾ Crosstalk refers to unwanted light interference between neighboring pixels.
³⁾ Clock gating in DDIs is a power-saving technique that switches off circuits to reduce power dissipation and improve energy conservation.
⁴⁾ Verified battery life increase was from 26 hours to 27 hours, based on video play time.}