Physical/Electrical Specifications; Ac Power Requirements; Dc Power Requirements; Conducted Noise Immunity - Seagate ST32430N - Hawk 2.1 GB Hard Drive Product Manual

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7.0

Physical/electrical specifications

7.1 AC power requirements: None
7.2

DC power requirements

The voltage and current requirements for a single drive are shown in the following table. Values indicated apply
at the drive power connector. The single ended power requirements includes the internal disc drive SCSI I/O
termination.
Voltage
Regulation [4] [2]
Average Idle Current [1]
Maximum Starting Current (Peak)[5][2] 0.61 A
Delayed Motor Start (Max) [3][5]
Operating Current [6]
Typ. [1]
Max. [1]
Max. (Peak)
[1] Measured with average reading DC ammeter. Instantaneous current peaks will exceed these values.
[2] A droop of up to -10% is permissible during the T2 portion of power up (see Figure 7.2.2-1).
[3] This condition occurs when the Motor Start Option is enabled and the drive has not yet received a Start
Motor command.
[4] See paragraph 7.2.1 "Conducted Noise Immunity".
[5] Peaks of 0.90 A (nominal) on +12 V will occur for no more than 100 ms total during the first 250 ms after
power is applied.
[6] Instantaneous peaks less than 5 msec. in duration are allowed.
General Notes from Table 7.2-1:
1. At powerup, the motor current regulator limits the 12 volt current to a peak value of less than 1.9
amperes, although instantaneous peaks may occur as stated in [7] above.
2. Operating condition is defined as random seek read of 64 blocks.
3. Minimum operating current loading for each supply voltage is not less than 38% of the maximum operating
current shown.
4. The +5 and +12 volt supplies shall employ separate ground returns.
5. 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.
7.2.1

Conducted noise immunity

Noise is specified as a periodic and random distribution of frequencies covering a band from DC to 10 mHz.
Maximum allowed noise values given below are peak to peak measurements and apply at the drive power
connector.
+5 V = 150 mV pp from 0 to 50 kHz and 45 mA pp from 50 kHz to 10 mHz.
+12 V = 150 mV pp from 0 to 50 kHz and 60 mA pp from 50 kHz to 10 mHz.
Product Manual - Hawk 2LP Family SCSI-2 (Volume 1), Rev. A
Table 7.2-1. DC power requirements
ST32430
Single Ended Differential I/O
+5 V +12 V +5 V
±5% ±5% +5%
0.36 A 0.35 A 0.51 A
2.0 A 0.71 A
0.56 A 0.22 A 0.56 A
0.80 A 0.40 A 0.90 A
0.85 A 0.42 A 1.05 A
1.1 A 1.9 A 1.3 A
ST31230
Single Ended
+12V +5 V +12 V
+5% ±5% ±5%
0.35 A 0.36 A 0.35 A
2.0 A 0.61 A 2.0 A
0.22 A 0.56 A 0.22 A
0.40 A 0.80 A 0.40 A
0.42 A 0.85 A 0.42 A
1.9 A 1.1 A 1.9 A
Differential I/O
+5 V +12V
+5% +5%
0.51 A 0.35 A
0.71 A 2.0 A
0.56 A 0.22 A
0.90 A 0.40 A
1.05 A 0.42 A
1.3 A 1.9 A