[2SMPB-02E] Datasheet Rev.05(Jun.,2017)

10

Copyright 2017 OMRON Corporation. All Rights Reserved.

4.3 Compensation of Pressure and Temperature

This section describes a typical measurement procedure and a calculation method after POR. This sensor has com-

pensation coefficients in internal Non Volatile Memory (NVM). The compensated pressure can be calculated by using

these values.

MSB of PRESS_TXDx, TEMP_TXDx and COE_** are sign bit.

①

Configure IO mode setting. Refer to IO_SETUP register section for more detail.

②

Read compensation coefficients which are stored in NVM. This procedure is sufficient just once after POR.

These values are used for a compensation calculation at the step ⑥ and ⑦.

③

Configure averaging times and power mode. Refer to CTRL_MEAS register section for more detail.

④

Read raw temperature data which are stored in TEMP_TXDx registers.

⑤

Read raw pressure data which are stored in PRESS_TXDx registers.

⑥

Compensated temperature can be calculated by using the below formula and the values of the step ② and ④.

2

2

1

0

Dt

a

Dt

a

a

Tr











Tr Calculation Result of Temperature ( Tr/256 = Temperature [degreeC] )

e.g.)

If Tr Value is 6400 LSB,

degreeC

25.00

C

LSB/degree

256

LSB

6400

Factor

Scaling

(LSB)

Value

Tr

(degreeC)

e

Temperatur







Dt Raw Temperature Data [digit] ( 20-24bits measurement value of TEMP_TXDx Reg. )

a0 Compensation Coefficient of PTAT (NVM resister: COE_a0_ex, COE_a0_0, COE_a0_1

)

a1 Compensation Coefficient of PTAT (NVM resister: COE_a1_0, COE_a1_1

)

a2 Compensation Coefficient of PTAT (NVM resister: COE_a2_0, COE_a2_1 )

START

① Configure IO mode setting by

“IO_STUP” register

② Read Compensation Coefficients

from N.V.M. ( COE_** )

③ Configure Averaging Times and

Power Mode

④ Read Uncompensated

Temperature Value ( TEMP_TXDx )

⑤ Read Uncompensated

Pressure Value ( PRESS_TXDx )

⑥ Compensate Temperature Value

⑦ Compensate Pressure Value

: Read/Write Values through Digital I/F

: Calculation by User MCU