C1 (15 Bit)
C5/I
1 Bit
DB14
DB9
DB13
DB8
DB12
DB7
DB11
DB6
DB10
DB9
DB8
DB3
DB7
DB6
DB1
DB5
DB0
DB4
DB5
DB3
DB4
DB2
DB1
DB0
DB1
DB10
Word1
Word2
C5/II (10 Bit)
C6 (6 Bit)
DB5
DB4
DB2
DB3
DB2
DB0
C4 (10 Bit)
C2/I (6 Bit)
DB9
DB9
DB8
DB8
DB7
DB7
DB6
DB6
DB5
DB4
DB3
DB3
DB2
DB2
DB1
DB1
DB0
DB0
DB11
DB5
DB10
DB4
DB9
DB8
DB7
DB1
DB6
DB0
Word3
Word4
C3 (10 Bit)
C2/II (6-Bit)
DB5
DB4
DB3
DB2
Fig. 4: Arrangement (Bit-pattern) of calibration data in Word1 to Word4.
SECOND-ORDER TEMPERATURE COMPENSATION
In order to obtain best accuracy over the whole temperature range, it is recommended to compensate for the
non-linearity of the output of the temperature sensor. This can be achieved by correcting the calculated
temperature and pressure by a second order correction factor. The second-order factors are calculated as
follows:
TEMP < 200
TEMP > 450
200 ≤ TEMP ≤ 450
yes
yes
yes
No correction
Low Temperatures
High Temperatures
T2 = 11*(C6+24)*(200 - TEMP)*(200 – TEMP) / 220
P2 = 3 *T2 * (P - 3500)/214
T2 = 3*(C6+24)*(450 - TEMP)*(450 – TEMP) / 220
P2 = T2 * (P - 10000)/213
T2 = 0
P2 = 0
Calculate pressure and temperature
TEMP = TEMP – T2
P = P – P2
Fig. 5: Flow chart for calculating the temperature and pressure to the optimum accuracy.
DA5540B_007
September 25th, 2006
11
00005540767 ECN 865
INTERSEMA [ INTERSEMA SENSORIC SA ]
