Battery Backup Unit (BBU)
BBU Design
The BBU provides power when loss of the main 12V is detected and operates through a series of three (3) modes as the BBU is working to preserve system operation and data integrity. These modes are: 5 second Ride Through, 1 second Power Shedding, 180-second Fire Hose Dump (data backup) (FHD). The modes are defined as:
Ride-Through (5 seconds): The BBU is design to support 5 seconds (from AC fail to OK_PWR_REDUCE asserted) of normal controller operation before the controller needs to initiate power shedding and the FHD operation. During the 5 seconds, 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 second period, the system will allow the drives to 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 one (1) second has elapsed, the application software 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.
(FHD) 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.- BBU power capability: Each BBU supports 562W/6s, and 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 has a 1ms overlap time for the BBU to take over
- Supports Hot Plug in/out
- Agency: UL2054, IEC62133, UL60950, IEC 62368, CB, BSMI
- Environmental: ROHS, REACH, WEEE