D6F-PH MEMS Differential pressure Sensor User’s Manual (A288)
18
8. Explanation of output data
The measured data is sent to the dedicated registers. These registers contain, respectively,
upper byte and lower byte of the sensing signals of the sensor.
For example, the compensated flow data is given by the concatenation COMP_DATA1_H &
COMP_DATA1_L in unsigned 16bit number. And the raw flow data is given by the
concatenation UCFM1_H & UCFM1_L and it is expressed as a 2’s complement of signed
16bit number.
8-1.
Data alignment
Sensing data is represented as 16bit numbers. The data is split and sent in two consecutive
bytes to Flow Registers in “Big Endian” format.
“Big Endian” means that the upper byte of the number is stored in a register at the lowest
address, and the lower byte at the highest address.
8-2.
Register content
・
COMP_DATA1_H & COMP_DATA1_L [D051h – D052h] : Compensated Data (unsigned)
These registers contain compensated flow rate data.
○
If pressure range is
±
50[Pa] or
±
500[Pa]
Dp[Pa] = (Pv - 1024)/60000*RANGE – RANGE/2 (RANGE = 100 or 1000)
Where
、
Pv is Register content stored in the Compensated Flow Data registers [D051h
– D052h].
○
If pressure range is 0-250[Pa]
Dp[Pa] = (Pv - 1024)/60000*RANGE ( RANGE = 250 )
Where
、
Pv is Register content stored in the Compensated Flow Data registers [D051h
– D052h].
・
TMP_H & TMP_L [D061h – D062h] : Temperature data (signed)
The values stored in these registers represent the temperature data measured by the
internal temperature of the ASIC.
The following formula can be applied to convert register data into temperature value.
Tv [
℃
] = (Rv – 10214) / 37.39
Where, Tv is Converted temperature value in the degC format, and Rv is Register
content stored in the Temperature Data register.
Note: Temperature data is for reference ONLY. Its accuracy is not specified in the
device specifications.