- Mon Aug 08, 2005 1:08 pm
#6518
reading the MMA7260 Spec can someone tell me what exactly the following two specs mean? (i figured out the rest of the spec, these are the only two that confuse me)
Noise
RMS (0.1 Hz – 1 kHz)(4) 4.7 mVRMS
Power Spectral Density RMS (0.1 Hz – 1 kHz)(4) 350 ug/sq(Hz)
are they trying to say the same thing in different ways or are these two different specs? For instance, the second spec, power spectral density, at 1000Hz the noise output (typical) is
350ug/sq(hz) * sq(1000) sq(hz) = 1.1067 mg RMS
now the above specs are at the 1.5g scale, which is speced at 800mV/g, so......
1.1067mg RMS * 1g/1000mg * 800mv/g = .88 mVRMS
which doesn't jive with the first spec
Noise
RMS (0.1 Hz – 1 kHz)(4) 4.7 mVRMS
Power Spectral Density RMS (0.1 Hz – 1 kHz)(4) 350 ug/sq(Hz)
are they trying to say the same thing in different ways or are these two different specs? For instance, the second spec, power spectral density, at 1000Hz the noise output (typical) is
350ug/sq(hz) * sq(1000) sq(hz) = 1.1067 mg RMS
now the above specs are at the 1.5g scale, which is speced at 800mV/g, so......
1.1067mg RMS * 1g/1000mg * 800mv/g = .88 mVRMS
which doesn't jive with the first spec