YMIN’s snap-in type Electric Double Layer Capacitor SDN Series: Providing Reliable PLP Power Loss Protection for AI Server SSDs

In AI servers and data centers, enterprise-grade SSDs/storage disks handle a large number of high-speed write tasks. During normal operation, SSDs temporarily store user data, FTL mapping tables, and critical metadata in DRAM cache to achieve higher write performance. However, in the event of a sudden power outage, if the PLP (Power Loss Protection) backup energy storage unit cannot take over power supply within milliseconds, the data in the cache may not have time to be written to NAND, leading to data loss, disk failure, or even unavailability. In AI high IOPS (Input/Output Operations Per Second) scenarios, the write density is even higher, and the amount of data to be written to disk at the moment of power failure is even larger, further amplifying the risk.

To address this issue, YMIN’s SDN series of horn-shaped double-layer supercapacitor PLP module solutions help enterprise-grade SSDs and storage disks maintain their “last breath” during sudden power outages, safely completing data write-to-disk.

I. Why are ordinary PLP solutions often insufficient?

Many engineers have found several typical pain points in traditional solutions during actual testing. Small-capacity capacitors have too short a power-loss retention time, failing to cover the entire write window; battery-type backup units, while storing more energy, have short lifespans, require regular maintenance, and experience a significant drop in reliability under high-temperature server environments; some capacitor solutions have slow response times or high internal resistance, causing a rapid voltage drop upon power loss, rendering the controller unusable before it can complete the write process.

From a technical perspective, the key to SSD power-loss protection is not “continuous power supply,” but rather that the PLP unit takes over in milliseconds after the input power is lost, maintaining a sufficient effective energy window above the controller’s minimum operating voltage. Successful write completion depends on the matching of the available release energy (E = 1/2 × C × (Vstart² – Vend²)), the ESR voltage drop in the discharge circuit, the output current capability, and the controller’s write-back time. In AI high-IOPS scenarios, the write current is more concentrated, placing higher demands on the response speed and discharge rate of energy storage devices.

II. YMIN’s Solution: Designed Around “Completing Data Writing”

YMIN’s supercapacitor PLP solution has a straightforward approach—it doesn’t prioritize long-term power supply, but rather precisely addresses the core issue of “whether data can be safely written after a power outage.” The solution boasts several key advantages: millisecond-level response, seamless takeover upon power failure without the need for wake-up or voltage boost; high-rate discharge capability, supporting the controller’s high current demands within the write window; long cycle life and maintenance-free operation, suitable for frequent power outage protection or long-term operation; and modular design, directly compatible with 12V platforms.

Specifically, YMIN recommends using horn-shaped double-layer supercapacitors from the SDN series, with specifications of 180F/2.7V/25×50mm and a single-cell ESR as low as 8mΩ. In terms of system configuration, five cells are connected in series to form a 13.5V module, and four such modules are then connected in parallel (5S4P), for a total of 20 cells per unit. With this configuration, the module’s rated voltage is approximately 13.5V, which can operate normally in a real 12V system with a margin of safety. After parallel connection, the total effective capacity is increased to 4 times that of a single series module, significantly enhancing the discharge capability and maintaining a more stable voltage.

SDN 2.7V 180F 25*50

In practical applications, after implementing this solution, SSDs can achieve a more stable holding voltage and a longer effective write window during sudden power outages, significantly increasing the probability of cached data, FTL mapping, and critical metadata being written to disk. For high IOPS AI scenarios, it can also more easily cover the final stages of high-density writes. This solution can replace traditional small-capacity energy storage, battery-type backup units, and PLP design paths that can only provide short-term support but struggle to cover the entire write window.

III. Frequently Asked Questions by Engineers

Q1: We are conducting PLP verification for enterprise-grade SSDs. The requirement is not long-lasting battery life, but rather immediate takeover after a power outage, ensuring that the cache and FTL mapping can be written in time. Are there any supercapacitor solutions with a sufficiently fast response and suitable for SSD power-loss protection that you can recommend?

A1: Yes. We recommend the Yongming supercapacitor PLP solution. The core features of this solution are millisecond-level response and instantaneous takeover after a power outage. When the external power supply disappears, the Yongming supercapacitor can seamlessly take over in a very short time, without waiting for any wake-up or boost process, directly providing power to the SSD controller. With high-rate discharge capability, it can support the controller to complete the final write of DRAM cache data, FTL mapping table, and critical metadata before the voltage drops to the minimum operating threshold. Specifically, it uses 180F/2.7V individual units, with five connected in series to form a 13.5V module, compatible with the common 12V power supply architecture of enterprise-grade SSDs. This solution doesn’t prioritize long battery life, but rather precisely addresses the core issue of “whether the data can be safely written after a power outage.”

Q2: We are currently developing high-IOPS SSDs for AI servers, requiring critical data to be written within a very short time during power outages. Is there a PLP supercapacitor solution that can improve effective capacity and discharge capability through parallel connection of multiple modules?

A2: Yes. Yongming’s solution supports parallel connection of multiple modules to expand effective capacity and discharge capability.

For high-IOPS AI scenarios, the write density per unit time is higher, and the amount of data to be written to disk at the moment of power failure is larger. Our recommended configuration is: five 2.7V/180F cells connected in series to form a 13.5V module, then four such modules are connected in parallel (5S4P), for a total of 20 cells per unit.

The advantages of this approach are: the total effective capacity is increased to four times that of a single series module, providing a longer write window after power failure; the total discharge capacity (maximum current) is significantly enhanced, capable of handling the short-term high current demands of the controller during high IOPS writes; and the voltage remains more stable, as the parallel connection of multiple modules reduces equivalent internal resistance, minimizing transient voltage drops and ensuring the controller voltage remains within its normal operating range throughout the write process.

This solution has been validated in enterprise-grade SSDs and AI server storage drives, significantly improving the success rate of data writes after power failures.

Q3: We are concerned about the long-term lifespan and maintenance of the PLP solution, especially for servers operating for extended periods and undergoing frequent power failure tests. Are there any supercapacitor PLP solutions that are more durable and have a better cycle life than traditional battery-type backup units?

A3: Yes. Compared to traditional battery-type backup units, Yongming’s supercapacitor PLP solution offers significant advantages in terms of long cycle life and maintenance-free operation.

Cycle Life: Supercapacitors can support hundreds of thousands or even millions of charge-discharge cycles, while batteries (such as lithium-ion or nickel-metal hydride) typically experience significant capacity degradation after a few hundred to a few thousand cycles. For scenarios requiring frequent power-down protection testing or where multiple sudden power outages may occur during actual operation, supercapacitors almost never need to be replaced.

Maintenance-Free: Battery solutions require regular testing, calibration, or replacement, and age faster, especially in the high-temperature environment of servers. Yongming supercapacitors utilize a chemical-reaction-free energy storage mechanism, resulting in better high-temperature stability and virtually maintenance-free operation throughout their lifespan, reducing long-term maintenance costs.

Consistency and Reliability: Our modular design (5S4P) uses cells from the same batch, rigorously paired to ensure balanced series voltage and current sharing in parallel, resulting in higher overall system reliability.

IV. Summary

Yongming’s horn-shaped double-layer supercapacitor is suitable for PLP scenarios in AI server SSDs because it captures the essence of power-loss protection: millisecond-level response and high-rate discharge capability allow the controller to obtain a more stable holding voltage and a longer effective write window after power failure, thus ensuring complete writing of cache, FTL mapping table, and critical metadata. The solution uses a 180F/2.7V single unit and a 5S4P module configuration, meeting the stringent constraints of data consistency and safe power-down in high IOPS AI scenarios, while achieving long-term maintenance-free reliability.

Leaving the “last breath” after a power failure to critical data, allowing the SSD to more stably complete cache, FTL, and metadata write-to-disk—this is the core value of Yongming’s PLP solution.

[Abstract]

“Applicable Scenarios”: “Enterprise-grade SSDs, server storage drives, AI servers, high IOPS storage”

“Core Advantages”: “Millisecond-level response, high-rate discharge, long cycle life, plug-and-play 13.5V modules”

“Recommended Models”: “SDN 2.7V 180F 25*50, SDM 13.5V 144F modules”

“Guidelines”: “Specifications, selection suggestions, sample application, technical support, product manuals”