EVAL-ADXRS646Z AD [Analog Devices], EVAL-ADXRS646Z Datasheet - Page 11

• Manufacturer Part Number: EVAL-ADXRS646Z
• Description: High Stability, Low Noise Vibration Rejecting Yaw Rate Gyro
• Manufacturer: AD [Analog Devices]

Data Sheet
IMMUNITY TO VIBRATION
Gyroscopes are designed to respond only to rotation. However,
all gyroscopes respond to linear motion as well, to varying
degrees. While bias stability is often used as the primary figure
of merit for evaluating high performance gyroscopes, many
additional error sources are present in real-world applications.
Especially in applications that require motion sensors, vibration
and acceleration are present, and the resulting errors often
overwhelm bias drift.
Its differential, quad-sensor design makes the
inherently resistant to vibration, without the need for
compensation. The excellent vibration immunity of the
ADXRS646
Figure 21 shows the
without random 15 g rms vibration applied at 20 Hz to 2 kHz.
Performance is similar regardless of the direction of input
vibration.
Figure 21.
0.00001
0.0001
0.001
0.01
(15 g RMS, 20 Hz to 2 kHz); Gyroscope Bandwidth Set to 1600 Hz
0.1
1
10
ADXRS646
is demonstrated in Figure 21 and Figure 22.
WITH VIBRATION
Output Response With and Without Random Vibration
NO VIBRATION
ADXRS646
100
FREQUENCY (Hz)
output response with and
1k
ADXRS646
10k
Rev. 0 | Page 11 of 12
To further improve immunity to vibration and acceleration,
some g-sensitivity compensation can be performed using an
accelerometer. This technique is most successful when the
response to vibration is constant regardless of vibration
frequency. Figure 22 demonstrates the
response to a 5 g sinusoidal vibration over the 20 Hz to 5 kHz
range. This figure shows that there are no sensitive frequencies
present and that vibration rectification is vanishingly small.
Accordingly, g-sensitivity compensation using an accelerometer
is possible where needed, but the inherent device performance
is sufficient for many applications.
Figure 22.
–0.02
–0.04
0.12
0.10
0.08
0.06
0.04
0.02
0
10
ADXRS646
Gyroscope Bandwidth Set to 1600 Hz
Sine Vibration Output Response (5 g, 20 Hz to 5 kHz);
100
FREQUENCY (Hz)
ADXRS646
1k
ADXRS646
dc bias
10k