Acoustics; Electromagnetic Immunity - Seagate ST3750641NS Product Manual

2.10

Acoustics

Drive acoustics are measured as overall A-weighted acoustic sound power levels (no pure tones). All mea-
surements are consistent with ISO document 7779. Sound power measurements are taken under essentially
free-field conditions over a reflecting plane. For all tests, the drive is oriented with the cover facing upward.
Note. For seek mode tests, the drive is placed in seek mode only. The number of seeks per second is defined
by the following equation:
(Number of seeks per second = 0.4 / (average latency + average access time)
Table 7: Fluid Dynamic Bearing (FDB) motor acoustics
ST3750641NS, ST3750841NS
ST3500631NS, ST3500831NS, ST3400621NS, ST3400821NS
ST3320621NS, ST3320821NS, ST3250621NS, ST3250821NS
*During periods of drive idle, some offline activity may occur according to the S.M.A.R.T. specification, which may increase acoustic and
power to operational levels.
2.11

Electromagnetic immunity

When properly installed in a representative host system, the drive operates without errors or degradation in
performance when subjected to the radio frequency (RF) environments defined in the following table:
Table 8: Radio frequency environments
Test Description
Electrostatic Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV
discharge
Radiated RF 80 to 1,000 MHz, 3 V/m,
immunity 80% AM with 1 kHz sine
900 MHz, 3 V/m, 50% pulse modulation @ 200 Hz
Electrical fast ± 1 kV on AC mains, ± 0.5 kV on external I/O
transient
Surge immunity ± 1 kV differential, ± 2 kV common, AC mains
Conducted RF 150 kHz to 80 MHz, 3 Vrms, 80% AM with 1 kHz sine A
immunity
Voltage dips, 0% open, 5 seconds
interrupts 0% short, 5 seconds
40%, 0.10 seconds
70%, 0.01 seconds
22
Idle*
2.7 bels (typ)
3.0 bels (max)
2.5 bels (typ)
2.8 bels (max)
Performance level
B
A
B
B
C
C
C
B
Barracuda ES+ Serial ATA Product Manual, Rev. B
Performance seek
3.2 bels (typ)
3.9 bels (max)
3.2 bels (typ)
3.5 bels (max)
Reference standard
EN 61000-4-2: 95
EN 61000-4-3: 96
ENV 50204: 95
EN 61000-4-4: 95
EN 61000-4-5: 95
EN 61000-4-6: 97
EN 61000-4-11: 94