Recent fluctuations in memory pricing have once again become a major focus in the semiconductor industry. As DRAM and specialty memory prices continue to rise, many system designs that rely on external memory are facing new cost pressures. For the Display Driver IC (DDI) industry, the impact extends beyond procurement costs—it also affects architectural decisions for next-generation products.
In small-display applications such as smartphone OLED panels, wearable devices, and compact automotive displays, DDIs typically integrate display buffers directly on-chip, using embedded SRAM as the frame buffer. This architecture offers several advantages, including low latency, low power consumption, simplified packaging, and support for thinner and lighter devices.
However, the situation differs for large displays such as TVs, high-end monitors, and large automotive central control screens. As resolutions increase to 4K and 8K, image data volume grows dramatically. If these systems rely entirely on embedded memory, the required SRAM area may expand significantly, resulting in larger die sizes, higher costs, and reduced yield. As a result, DDIs for these applications have traditionally adopted external DRAM or SDRAM to achieve greater memory capacity at a lower cost per bit.
However, market conditions are changing. The primary advantage of external memory has always been its low capacity cost, but its weaknesses are becoming increasingly apparent. The first issue is supply chain risk. External memory pricing is highly sensitive to economic cycles, capacity adjustments, and supply-demand imbalances, making BOM costs difficult to predict. The second issue is system power consumption and latency. Frequent data transfers between the DDI and external memory not only increase I/O power consumption but also create bandwidth bottlenecks.
In contrast, although embedded SRAM occupies more die area, it delivers extremely high bandwidth and ultra-low latency. As demand for higher refresh rates and better display quality continues to rise, its technical value is becoming increasingly significant. More importantly, when external memory prices rise while SRAM costs remain relatively stable, companies are likely to reassess the cost trade-offs of different memory architectures.
In the past, many companies considered embedded SRAM too expensive and therefore preferred external memory. But when external memory is no longer inexpensive—and may even introduce supply risks—increasing the embedded SRAM capacity within DDI may become a more strategic choice.
Of course, embedded SRAM also introduces new challenges. As SRAM capacity increases, the memory area ratio within the chip continues to grow. In advanced process nodes, SRAM already accounts for more than 50% of die area in many SoCs. The larger the memory, the higher the probability that process defects will create fail bits, directly impacting overall yield. Therefore, if DDI architectures are moving toward larger SRAM capacity, a critical factor is whether the backend flow includes sufficiently mature memory test and repair capabilities.
Through MBIST (Memory Built-In Self-Test) and Memory BISR (Memory Built-In Self-Repair) technologies, chips can identify defective SRAM regions during wafer testing and repair them using redundancy mechanisms, effectively improving overall yield. This enables companies to increase SRAM capacity without being constrained by yield concerns, allowing them to improve performance while maintaining manufacturing stability.
This is where iSTART-TEK demonstrates its core strength. With deep expertise in memory test, repair, and diagnosis technologies, iSTART-TEK provides comprehensive MBIST, MBISR, and memory test algorithm platforms to help customers establish high-coverage SRAM test strategies during the design stage. As SRAM capacity continues to grow in DDIs, AI chips, and automotive SoCs, iSTART-TEK helps customers improve memory yield, reduce production risk, and accelerate time-to-market.