AK8999AD Datasheet, PDF (39/68 Pages) Asahi Kasei Microsystems – Pressure Sensor Control IC

CONFIDENTIAL
[AK8999A/AW/AD]
6) The Compensation of the 2nd Order Temperature Characteristics of Offset and Span Voltage
Offset temperature drift and sensitivity temperature drift characteristics of a pressure sensor can be adjusted by the
1st order compensation coefficient or the 2nd order compensation coefficient by piecewise linear approximation.
The AK8999A can compensate the 1st and 2nd order temperature characteristics of offset and span voltage
temperature drift. The compensation of the quasi 2nd order temperature characteristics uses the piecewise linear
approximation that has each correction coefficient for the high and low temperature side on the basis of 25C.
When the 1st order temperature characteristics of offset and span voltage temperature drift is adjusted, the offset
and span voltage temperature coefficients are calculated from the measurement results of at least two
temperatures (for example, 25C and -40C and/or 105C) and set the same coefficient for the high and low
temperature side.
When the quasi 2nd order temperature characteristics of offset and span voltage temperature drift is adjusted, the
offset and span vltage temperature coefficients are calculated from the measurement results for each the high
and low temperature side (for example, 25C and -40C and/or 105C) and set separately.
When the quasi 2nd order temperature characteristics is compensated by using the piecewise linear
approximation, the adjustment error (Span adjustment error : 0.080%FS max., Offset adjustment error : 0.222%FS
max.) can be appeared by the comparator offset etc. on the turning point near 25C.
The compensation of offset voltage temperature characteristics @VOUT
VOUT [V]
Low temp.
High temp.
0.222%FS
-40
25
105 _{Temp. [C]}
The compensation of span voltage temperature characteristics @VOUT
VOUT [V]
MS1600-E-00
Low temp.
High temp.
0.080%FS
-40
25
- 39 -
105 Temp. [C]
2014/05