Specifications
4-6Quantum Atlas 10K II Ultra 160/m SCSI Hard Disk Drives
4.5 POWER
The Quantum Atlas 10K II Ultra 160/m SCSI hard disk drive operates from two
supply voltages:
+12V ±5%
+5V ±5%
The allowable ripple and noise (60Hz – 100MHz) is 150 mV peak-to-peak, for the
+12V supply and 75 mV peak-to-peak, for the +5V supply.
4.5.1 Power Sequencing
Power may be applied in any order or manner, or open either the power or power
return line with no loss of data or damage to the disk drive. However, data may be
lost in the sector being written at the time of a power loss. The disk drive can
withstand transient voltages of +10% to –100% from nominal while powering up or
down.
4.5.2 Power Reset Limits
When powering up, the disk drive remains reset until both VHT reset limits in Table
4-5 are exceeded. When powering down, the drive becomes reset when either supply
voltage drops below the VLT threshold.
Table 4-5 Power Reset Limits*
DC VOLTAGE THRESHOLD
+5V VLT = 4.25V minimum
VHT = 4.365V maximum
+12V VLT = 10.16V minimum
VHT = 10.48V maximum
* Includes a 75 mV peak-to-peak ripple on +5V or 150 mV
peak-to-peak ripple on +12V to maximize or minimize values.