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Hi, I would to know the range of frequencies LIS2HH12. I also would to know the sensitivity of this accelerometer. I've read 0.061 mg/digit, but I need the sensitivity expressed in V/ms2. Thank you so much!

DFian.1
Associate
 
1 REPLY 1
Eleon BORLINI
ST Employee

Hi @DFian.1​ ,

the frequency range for the LIS2HH12 accelerometer is determined by the maximum output data rate (ODR) for the device, which is 800Hz. The max detectable frequency is so ODR/2 = 400Hz (see datasheet, p.32). Please note that if you run in high resolution, the bandwidth will be reduced according to the (datasheet, same page).

For the sensitivity, please note that the LIS2HH12 is a digital accelerometer: it means that the output is codified in bits. in the internal acquisition chain, the signal from the MEMS capacitance C variation is converted into voltage V, than -simplifying- pass through an ADC and is codified in bits, and after multiplying the sensitivity for the reg output content (for example, in the OUT_X_L (28h) - OUT_X_H (29h) registers), you can get the physical units of interest (milli g or m/s^2). So I don't believe it is useful to go back from the bits to the voltage...

float_t lis2hh12_from_fs2g_to_mg(int16_t lsb)
{
  return ((float_t)lsb * 0.061f);
}

 You can of course convert the 0.061 mg/digit into m/s^2/digit --> 1/(0.061 * 9.81) *1000 m/s^2 = 600k digit/m/s^2

-Eleon