ADXRS613 Analog Devices, Inc., ADXRS613 Datasheet - Page 10

• Manufacturer Part Number: ADXRS613
• Description: ?150?/sec Yaw Rate Gyroscope
• Manufacturer: Analog Devices, Inc.

ADXRS613
ADXRS613 AND SUPPLY RATIOMETRICITY
The ADXRS613 RATEOUT and TEMP signals are ratiometric
to the V
temperature outputs are proportional to V
ADXRS613 is most easily used with a supply-ratiometric ADC
that results in self-cancellation of errors due to minor supply
variations. There is some small error due to nonratiometric
behavior. Typical ratiometricity error for null, sensitivity, self-
test, and temperature output is outlined in Table 4.
Note that V
Table 4. Ratiometricity Error for Various Parameters
Parameter
ST1
ST2
Null
Sensitivity
V
TEMP
Mean
Sigma
Mean
Sigma
Mean
Sigma
Mean
Sigma
Mean
Sigma
RATIO
RATIO
voltage, that is, the null voltage, rate sensitivity, and
V
−0.4%
0.6%
−0.4%
0.6%
−0.04%
0.3%
0.03%
0.1%
−0.3%
0.1%
must never be greater than AV
S
= V
RATIO
= 4.75 V
V
−0.3%
0.6%
−0.3%
0.6%
−0.02%
0.2%
0.1%
0.1%
−0.5%
0.1%
RATIO
S
= V
. Thus, the
CC
RATIO
.
= 5.25 V
Rev. 0 | Page 10 of 12
NULL ADJUSTMENT
The nominal 2.5 V null is for a symmetrical swing range at
RATEOUT (1B, 2A). However, a nonsymmetrical output swing
may be suitable in some applications. Null adjustment is
possible by injecting a suitable current to SUMJ (1C, 2C). Note
that supply disturbances may reflect some null instability.
Digital supply noise should be avoided particularly in this case.
SELF-TEST FUNCTION
The ADXRS613 includes a self-test feature that actuates each of
the sensing structures and associated electronics as if subjected
to angular rate. It is activated by standard logic high levels
applied to Input ST1 (5F, 5G), Input ST2 (4F, 4G), or both. ST1
causes the voltage at RATEOUT to change about −1.9 V, and
ST2 causes an opposite change of +1.9 V. The self-test response
follows the viscosity temperature dependence of the package
atmosphere, approximately 0.25%/°C.
Activating both ST1 and ST2 simultaneously is not damaging.
ST1 and ST2 are fairly closely matched (±5%), but actuating
both simultaneously may result in a small apparent null bias
shift proportional to the degree of self-test mismatch.
ST1 and ST2 are activated by applying a voltage of greater than
0.8 × V
vated by applying a voltage of less than 0.2 × V
and ST2 pins. The voltage applied to ST1 and ST2 must never
be greater than AV
CONTINUOUS SELF-TEST
The one-chip integration of the ADXRS613 gives it higher
reliability than is obtainable with any other high volume
manufacturing method. In addition, it is manufactured under
a mature BiMOS process with field-proven reliability. As an
additional failure detection measure, a power-on self-test can be
performed. However, some applications may warrant continuous
self-test while sensing rate. Details outlining continuous self-test
techniques are also available in the AN-768 Application Note,
Using the ADXRS150/ADXRS300 in Continuous Self-Test Mode
at www.analog.com.
RATIO
to the ST1 and ST2 pins. ST1 and ST2 are deacti-
CC
.
RATIO
to the ST1