The Best fitting Non-Volatile Memory Solution for Surveillance Cameras: Optimum Selection and Study Case Explanation
There are many different memories available in the industry, therefore sometimes finding the right solution for companies’ projects can be a real challenge.
To assist professionals in selecting the best fitting non-volatile memory for surveillance cameras application, and we provide examples of their utilization below. We also introduce design considerations based on the limitations of NAND flash and the characteristics of emerging NVMs such as FeRAM and ReRAM.
Role and Requirements of Non-Volatile Memory for Surveillance Cameras
In surveillance camera systems, non-volatile memory (NVM) is essential for storing recorded footage and metadata. Particularly for edge recording and real-time processing applications, it requires highly reliable recording performance, long lifespan, and resistance to sudden power outages. Selecting the optimal NVM according to these requirements is directly linked to the overall system stability and data integrity.
Storage Requirements for Video Recording and Buffering (Write Frequency, Capacity, Accessibility)
For video recording and buffer processing in surveillance cameras and avanced security cameras, non-volatile memory (NVM) capable of handling large capacities and high-frequency write operations is required. As recording resolution increases, the volume of data also grows, making storage capacities of at least several tens to several hundreds of gigabytes necessary. Additionally, there are many situations that demand real-time access, such as instant recording triggered by event detection and pre-event caching. Therefore, a balanced read/write speed is crucial. Any access latency can lead to recording failures or response delays, which, in turn, can affect the overall reliability of the surveillance system.
Reliability and Data Preservation Requirements During Power Outages or Interruptions
Surveillance cameras are devices designed to operate continuously, and it is essential to equip them with non-volatile memory (NVM) capable of preserving recorded data in the event of sudden power interruptions or outages. If the data being recorded is lost at the moment of a power failure, there is a significant risk that critical footage cannot be reviewed. Therefore, memory characteristics that allow for low write latency and immediate data retention are required. It is important to design the system in conjunction with buffer control and cache mechanisms to prevent data loss immediately after writing. The design must also ensure that the system can start up normally after power is restored.
Impact of Environmental Conditions such as Temperature, Signal Degradation, and Durability
Security cameras are often installed outdoors or in harsh environments, making them devices that are highly susceptible to external factors such as temperature fluctuations, humidity, vibration, and static electricity. Consequently, a Non-Volatile Memory for surveillance cameras is required to operate stably under these conditions, with particular attention to leakage current and signal degradation caused by temperature, as these significantly affect memory performance and lifespan. Additionally, durability that allows stable data retention over long periods, specifically high P/E (program/erase) cycle performance, is crucial. Selecting memory in conjunction with an evaluation of the usage environment is key to ensuring long-term stable operation.
Implementation and Limitations of Conventional NAND Flash (SD/eMMC/NAND Storage)
The most commonly used non-volatile memory in surveillance cameras is NAND flash-type SD cards or eMMC. Their major advantages are low cost and the ability to provide large storage capacity. However, there are also inherent design limitations, such as finite write endurance and access latency. While they have a proven track record for video recording applications, challenges remain for use in scenarios where edge AI processing or real-time performance is critical. Therefore, appropriate selection based on the intended usage is necessary.
Comparison of SLC/MLC/TLC/QLC Characteristics and Durability Trade-offs
NAND flash is categorized based on the number of bits per cell into SLC (1 bit), MLC (2 bits), TLC (3 bits), and QLC (4 bits), with higher bit densities offering greater cost efficiency. However, this comes at the expense of durability (P/E cycles), which significantly decreases, and data retention periods tend to be shorter. While SLC is expensive but long-lasting and suitable for industrial applications, QLC is inexpensive and high-capacity but has an extremely short rewrite lifespan, making it unsuitable for applications with frequent writes, such as surveillance. Selecting the appropriate grade according to the intended usage is directly linked to long-term reliability.
Flash Write Delays, Block Erase Limitations, and Wear Leveling Techniques
Using NAND flash memory requires block-level erasure before write operations, which makes it prone to delays during random write operations. To mitigate this limitation, flash memory controllers employ a technique called wear leveling, which distributes write operations to prevent uneven degradation of memory cells. However, the increasing complexity of these control mechanisms raises the overall system design difficulty and can lead to unpredictable performance degradation and reduced lifespan. Careful design is especially critical for surveillance cameras that are intended for long-term continuous operation.
Points and Precautions for Selecting microSD/SD Cards for Surveillance Use
Generally, commercially available microSD cards are designed for household use and are not suitable for professional surveillance applications in terms of durability and reliability. Industrial-grade SD cards are often based on SLC and feature high durability, allowing them to handle long-term continuous recording and high-frequency write operations. For card selection, it is important to evaluate not only the write speed but also temperature resistance, error correction capabilities (ECC), and data protection features in the event of power loss. Additionally, setting appropriate formatting intervals and replacement cycles for the cards is necessary.
Design Options Using Emerging NVM (ReRAM, MRAM, PCM, FeRAM, etc.)
In recent years, emerging non-volatile memories such as ReRAM, MRAM, PCM or FeRAM, have drawn attention as alternatives to conventional NAND-type memory. These technologies offer characteristics such as high-speed writing, low power consumption, and high endurance, making them promising solutions for use in edge AI and surveillance systems that require real-time processing.
On the other hand, challenges related to mass production, cost, and compatibility remain, requiring designers to carefully select the appropriate technology based on the intended application.
Edge AI and Model Retention Applications Using ReRAM (Avoiding Startup Delays, etc.)
ReRAM (Resistive RAM) features low-voltage operation, high-speed writing, and extremely low read latency. This allows AI models on edge AI devices to be accessed directly from ReRAM rather than being loaded into DRAM at each startup, significantly reducing startup delays. This is particularly effective in scenarios where devices, such as surveillance cameras, are not continuously active, or where rapid recovery from low-power modes is required. Additionally, its high write endurance makes it suitable for storing configuration information and learning results.
Characteristics of MRAM/PCM: Comparison of Read/Write Speed, Endurance, and Power Consumption
MRAM (Magnetoresistive Random Access Memory) combines extremely fast read/write performance with high durability. It utilizes magnetism rather than voltage during write operations, which reduces cell degradation. PCM (Phase-Change Memory) allows multi-level data storage by exploiting temperature changes, making it advantageous for high-density applications. Both types offer significantly longer rewrite lifespans compared to NAND and are superior in terms of energy efficiency. In applications such as surveillance cameras, they are beneficial for processes like frequent log writing and storing inference results.
Characteristics of FeRAM and Its Advantages for Surveillance Camera Applications
FeRAM (Ferroelectric RAM) is a non-volatile memory that features high-speed access and write endurance comparable to SRAM, while retaining data even when the power is cut off. With extremely low write latency and very low power consumption, FeRAM is highly effective in systems requiring real-time processing and frequent log recording, such as surveillance cameras. It is particularly well-suited for applications that involve recording small amounts of data at high frequency, including configuration information, logs, sensor state histories, and firmware event records. Additionally, FeRAM offers high reliability due to its cell structure, with minimal degradation from repeated write cycles, enabling long-term operation without maintenance. The ability to simultaneously achieve “immediacy” and “durability,” which are essential requirements for surveillance use, represents a notable advantage over other emerging non-volatile memories.
Implementation Challenges (Write Endurance Constraints, Error Correction, Process Compatibility)
While emerging non-volatile memories (NVMs) offer numerous advantages over conventional memory, several implementation challenges remain. For instance, ReRAM can experience bit errors due to write variability, necessitating a design that works in conjunction with ECC (Error Correction Codes). Additionally, compatibility with CMOS processes, limitations on the deployable memory capacity, and ensuring stable supply as a product are also significant concerns. In long-lifecycle applications such as monitoring, it is essential to evaluate and make adoption decisions from a long-term perspective, taking these factors into account.
Summary
The evolution of non-volatile memory has significantly enhanced both the design flexibility and performance of surveillance camera systems. By selecting the optimal NVM according to system requirements, it is possible to build a smart surveillance environment that combines reliability, scalability, and energy efficiency. In particular, when considering future integration with edge AI, the adoption of emerging NVM technologies becomes an important design consideration.
Summary of Key Points for selecting a suitable Non-Volatile Memory for surveillance cameras
When choosing non-volatile memory suitable for surveillance cameras, it is necessary to comprehensively evaluate factors such as “write frequency,” “durability,” “power-loss tolerance,” and “environmental resistance” according to the intended use. For NAND-type memory, industrial SD cards based on SLC are candidates, while emerging NVMs such as MRAM and ReRAM are also options. It is important to make decisions not solely based on cost, but from the perspective of total cost of ownership (TCO), including long-term reliability and replacement costs. It is recommended to clarify memory requirements from the early stages of design.
List of Design Considerations and Trade-Offs
When selecting non-volatile memory, there are multiple trade-offs to consider, such as capacity versus durability, speed versus power consumption, and cost versus performance. For example, SLC NAND offers high durability but comes at a higher cost, whereas QLC NAND is inexpensive but has a shorter lifespan. Additionally, with emerging NVM technologies, process compatibility and mass production capabilities can pose challenges, requiring a balance with implementation risks. Clearly understanding these trade-offs and determining the configuration that best meets your company’s design requirements is crucial for maintaining long-term quality.
Trends in Technology and Key Areas of Focus Ahead
In the future of non-volatile memory (NVM) technologies, compatibility with AI-integrated surveillance systems will be a critical factor. As the trend toward processing and storing inference models and learning data on-device continues, high-speed, high-durability memories such as FeRAM and MRAM are expected to play an important role. Additionally, optimizing memory architecture to achieve real-time processing while minimizing power consumption will likely advance. In the surveillance camera market, the utilization of these advanced NVM technologies will serve as a differentiating factor, making their strategic implementation from the design stage essential.
Related Links
・RAMXEED FeRAM Product Lineup
FeRAM Product List｜RAMXEED
・RAMXEED ReRAM Product Lineup
ReRAM Product List｜RAMXEED
