MS5534AP Datasheet, PDF (10/21 Pages) List of Unclassifed Manufacturers – BAROMETER MODULE

Start
Read calibration data (factory calibrated) from
PROM of MS5534
Word1, Word2, Word3 and Word4 (4x16 Bit)
Basic equations:
Convert calibration data into coefficients:
(see bit pattern of Word1-Word4)
C1: Pressure sensitivity
C2: Pressure offset
C3: Temperature coefficient of pressure sensitivity
C4: Temperature coefficient of pressure offset
C5: Reference Temperature
C6: Temperature coefficient of the temperature
(15 Bit)
(12 Bit)
(10 Bit)
(10 Bit)
(11 Bit)
(6 Bit)
SENST1
OFFT1
TCS
TCO
Tref
TEMPSENS
Example:
Word1 = 50426
Word2 = 9504
Word3 = 48029
Word4 = 55028
C1 = 25213
C2 = 1908
C3 = 859
C4 = 750
C5 = 148
C6 = 32
Read digital pressure value from MS5534A
D1 (16 Bit)
D1 = 17000
Read digital temperature value from MS5534A
D2 (16 Bit)
Calculate calibration temperature
UT1=8*C5+20224
Calculate actual temperature
Difference between actual temperature and reference
temperature:
dT = D2 - UT1
Actual temperature in °C:
TEMP = (200 + dT*(C6+50)/2¹⁰)/10
dT(D2) = D2 - Tref
TEMP(D2)=20°+dT(D2)*TEMPSENS
Calculate temperature compensated pressure
Offset at actual temperature:
OFF = C2*4 + ((C4-512)*dT)/2¹²
Sensitivity at actual temperature:
SENS = C1 + (C3*dT)/2¹⁰ + 24576
X = (SENS * (D1-7168))/2¹⁴ - OFF
Temperature compensated pressure:
P = X*100/2⁵ + 250*100 (0.01mbar resolution)
P = X*10/2⁵ + 250*10 (0.1mbar resolution)
OFF(D2)=OFFT1+TCO*dT(D2)
SENS(D2)=SENST1+TCS*dT(D2)
P(D1,D2)=D1*SENS(D2)-OFF(D2)
D2 = 22500
dT = 1092
TEMP = 287
= 28.7 °C
OFF = 7695
SENS = 50705
X = 22732
P = 96037
= 960.37 mbar
Display pressure and temperature value
Fig. 3: Flow chart for pressure/temperature reading and software compensation.
Notes:
1. Readings of D2 can be done less frequently, but the display will be less stable in this case
2. For a stable display of 0.1mbar resolution, it is recommended to display the average of 8 subsequent
pressure values.
DA5534_022.doc
July 17th, 2002
10
ECN493