Power Dissipation; Figure 4. Typical Barracuda 50 Family Drive +5 V Current Profile - Seagate ST150176LW Product Manual

Barracuda 50 Product Manual, Rev. C
+5 Volt Current during spindle start – Typical Amperes
+5V
Current
(amps)
1.0
A
0.5
0.0
Figure 4. Typical Barracuda 50 family drive +5 V current profile
6.3

Power dissipation

For drives using single-ended interface circuits, typical power dissipation under idle conditions is 11.82 watts
(40.3 BTUs per hour).
For drives using differential interface circuits, typical power dissipation under idle conditions is 11.87 watts
(40.5 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following two I/O rate curves (see
Figures 5 and 6). Locate the typical I/O rate for a drive in your system on the horizontal axis and read the cor-
responding +5 volt current, +12 volt current, and the total watts on the vertical axis. To calculate BTUs per hour,
multiply watts by 3.4123.
T T0 T2 T2 T2
0.0 4 8 12
Component
Nominal (average) DC curve
16 20 24
Seconds
AC
T5
28 32
21