Seagate Savvio 10K Product Manual page 32

Table 13:
ST936701SS
Voltage
Regulation
Avg idle current DCX
Maximum starting current
(peak DC) DC
(peak AC) AC
Delayed motor start (max) DC 3σ
Peak operating current:
Typical DCX
Maximum DC
Maximum (peak) DC
[1] Measured with average reading DC ammeter. Instantaneous +12V current peaks will exceed these val-
ues. Power supply at nominal voltage. N (number of drives tested) = 6, 35 Degrees C ambient.
[2] For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching
9,936 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been
completed and that the drive is able to accept selection by the host initiator.
[3] See +12V current profile in Figure 2.
[4] This condition occurs after OOB and Speed Negotiation completes but before the drive has received the
Notify Spinup primitive.
[5] See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
[6] Operating condition is defined as random 8 block reads with 295 I/Os per second for ST973401SS drives
and 285 I/Os per second for ST936701SS drives. Current and power specified at nominal voltages.
Decreasing +5 volt supply by 5% increases 5 volt current by 3.2%. Decreasing +12 volt supply by 5%
increases 12 volt current by 2.1% for ST973401SS models (2% for ST936701SS models).
[7] During idle, the drive heads are relocated every 60 seconds to a random location within the band from
three-quarters to maximum track.
General DC power requirement notes.
1. Minimum current loading for each supply voltage is not less than 1.7% of the maximum operating current
shown.
2. The +5V and +12V supplies should employ separate ground returns.
3. Where power is provided to multiple drives from a common supply, careful consideration for individual
drive power requirements should be noted. Where multiple units are powered on simultaneously, the peak
starting current must be available to each device.
4. Parameters, other than spindle start, are measured after a 10-minute warm up.
5. No terminator power.
26
DC power requirements
ST936701SS
3 Gbit mode
Notes (Amps)
+5V
[5] ±5%
[1] [7] 1.06
3σ [3] 1.19
3σ [3] 1.42
[1] [4] 1.05
[1] [6] 1.08
3σ [1] 1.09
3σ 1.46
ST936701SS
1.5 Gbit mode
(Amps) (Amps) (Amps)
+12V [2] +5V +12V [2]
±5% [2] ±5% ±5% [2]
0.18 1.06 0.18
1.81 1.19 1.82
2.94 1.41 2.93
0.05 1.05 0.05
0.47 0.98 0.46
0.50 0.99 0.47
1.46 1.34 1.48
Savvio SAS Product Manual, Rev. D