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Controller

Battery Backup Unit (BBU)

Warning: The BBU contains enough power and current to exceed 240VA.
Note: To prevent electrical shock, the BBU is designed to ensure its pins are turned off when it is disconnected from the system.

BBU Design

The BBU provides power when loss of the main 12V is detected and operates through a series of modes as the BBU is working to preserve system operation and data integrity. These modes are: 5 second Ride Thru, 1 second Power Shedding, 180-second fire hose dump (data backup) (FHD). These 3 modes are defined as:

Ride-Thru (5 seconds): The BBU is design to support 5 seconds (from AC fail to OK_PWR_REDUCE asserted) of the normal canister operation before the Canister needs to initiate power shedding and the FHD operation. During the 5 second, the Drive Bays could be off-line and maintain the full operation. The CPU will detect the drives are off-line and hold any pending transactions, per the software/firmware architecture.

If main power returns within this 5-seconds period, the system will allow the drives to spin-up (come back online) again, and normal operation will resume without doing the FHD cycle.

If the system fails to signal power reduction (no OK_PWR_REDUCE asserted) and the CPLD's 20-second countdown elapses, the system will enter shutdown mode without initiating the fire hose dump (FHD) backup cycle.

Power Shedding (1 second): After the above 1seconds have elapsed, the application SW will force the CPU to transition to a lower power mode and shuts down all un-necessary I/O (PCIe, etc.) traffic. It will then notify the CPLD, that it can remove power from the devices not needed during the Data Backup operation.

Data Backup (180 seconds): The application SW now has the CPU copying data from DRAM to the SSD Flash Module. It is estimated that copying 70GB to SSD may take up to 180 seconds.

Backup Complete: Once the CPU has completed the Data Backup, the System SW will notify the Complex Programmable Logic Device (CPLD) and power down.
Note: After the initial 5-second Ride-Thru period, the system will proceed with the full data backup cycle, regardless of whether the main power is restored before the cycle's completion.
Note: If the main power is restored after the 5-second Ride-Thru but before the fire hose dump (FHD) backup is complete, the system will switch back to using the main 12V power rail to finish the FHD backup, conserving BBU energy. Once the FHD backup is finished, the system will reboot, restore the saved data, and return to operational status.
  • BBU power capability: Single BBU supports 562W/6s, then 325W/180S for two cycles
  • Life cycle: Two (2) years shelf life + five (5) years operation
  • Operating temperature range: 13℃ - 50℃ (45℃ above 1829m1)
  • Charger: Internal Bi-direction Buck-boost Charger with normal and fast charge capability
  • Calibration: Self discharge (Power resistor or Bi-direction Buck-boost) for BBU calibration
  • EPOW from PSU to get 1ms overlap time for BBU taking over
  • Support Hot Plug in/out
  • Agency: UL2054, IEC62133, UL60950, IEC 62368, CB, BSMI
  • Environmental: ROHS, REACH, WEEE
1 Above 1829m the maximum air temperature is de-rated by 1°C per additional 175m. Temperatures above 45°C may reduce life of pack.

Last updated: November 19, 2024