DiamondMax 21 Serial ATA Product Manual, Rev. C 25

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)
*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.
**Measured in performance mode.
***Measured in quiet mode.
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: Fluid Dynamic Bearing (FDB) motor acoustics

Idle* Seek
STM3500630AS 2.8 bels (typ)
3.0 bels (max)
3.7 bels (typ)**
3.9 bels (max)**
STM3320620AS, STM3320820AS, and STM3250820AS 2.5 bels (typ)
2.9 bels (max)
3.0 bels (typ)**
3.2 bels (max)**
STM3250824AS 2.7 bels (typ)
2.9 bels (max)
3.4 bels (typ)**
3.6 bels (max)**
STM3250310AS 2.6 bels (typ)
2.7 bels (max)
2.7 bels (typ)***
2.8 bels (max)***
STM3160815AS, STM3160215AS, STM380815AS
STM380215AS and STM340215AS
2.8 bels (typ)
3.0 bels (max)
3.0 bels (typ)***
3.2 bels (max)***

Table 9: Radio frequency environments

Test Description Performance level Reference standard
Electrostatic
discharge
Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV B EN 61000-4-2: 95
Radiated RF
immunity
80 to 1,000 MHz, 3 V/m,
80% AM with 1 kHz sine
900 MHz, 3 V/m, 50% pulse modulation @ 200 Hz
A EN 61000-4-3: 96
ENV 50204: 95
Electrical fast
transient
± 1 kV on AC mains, ± 0.5 kV on external I/O B EN 61000-4-4: 95
Surge immunity ± 1 kV differential, ± 2 kV common, AC mains B EN 61000-4-5: 95
Conducted RF
immunity
150 kHz to 80 MHz, 3 Vrms, 80% AM with 1 kHz sine A EN 61000-4-6: 97
Voltage dips,
interrupts
0% open, 5 seconds
0% short, 5 seconds
40%, 0.10 seconds
70%, 0.01 seconds
C
C
C
B
EN 61000-4-11: 94