Pressure sensors
C32 series
Absolute pressure sensor die for wet media
Preliminary data
αs and βs are the linear and nonlinear temperature coefficient of the sensitivity respectively (see 15)).
Therefore TCV0+ and TCV0– are defined for the measurement temperature range by:
Vo(Tmin ) − Vo(25°C)
Tmin − 25°C
Vo(Tmax ) − Vo(25°C)
Tmax − 25°C
TCVo−
=
TCVo+
=
12)
13)
Full scale value FS
Sensitivity S
The sensitivity is defined for a bridge voltage power supply VDD = 5 V. It can be determined by the formula:
FS = Vout (prmax ) − Vo
Vout (prmax ) − Vo
S =
prmax
This parameter is tested for process control on samples, mounted on AK transducer package (AK2 series).
14)
Nonlinearity L
This parameter may be influenced by assembly.
The nonlinearity is measured using the endpoint method. Assuming a characteristic, this can be approximated
by a polynomial of second order, where the maximum is at px = pr,max/2. The nonlinearity is defined at px = pr,max/2,
using the equation:
Vout (px ) − Vo
px
L =
−
Vout (pr,max ) − Vo pr,max
This parameter is tested for process control on samples, mounted on AK transducer package (AK2 series).
15)
Temperature coefficients of sensitivity αRs and βRs
These parameters may be influenced by assembly.
:
The temperature coefficients of sensitivity are tested for design verification on samples, mounted on AK transducer
package (AK2 series) over a reduced temperature range Tmeas min = –20 °C to Tmeas max = 80 °C with TR = 25 °C.
The temperature coefficients of first and second order are defined with the polynomial:
,
,
2
S(T)=S(T=25°C) 1+αS
(
T−25°C
)
+βS
(
T−25°C
)
The coefficients αS and βS are calculated using the three measurement points of S(T) at Tmeas,min, TR and Tmeas,max
.
16)
Pressure hysteresis pHys
The pressure hysteresis is the difference between output voltages at constant pressure and constant temperature while
applying a pressure cycle with pressure steps of pr, min, p1, p2, p3, pr,max, p3, p2, p1, pr, min
:
Vout,2(pk )− Vout,1(pk )
pHys =
FS
With k = min, 1, 2, 3, max. The pressure steps are: prmin = 0, p1 = 0.25·pr,max, p2 = 0.5·pr,max, p3 = 0.75·pr, max, pr,max
This parameter is tested for design verification on samples, mounted on AK transducer package (AK2 series).
.
17)
Reliability data
For long-term stability of offset voltage LTSV0 please refer to the defined Aktiv Sensor’s standard AS100001 in chapter
“Reliability data” on the internet.
AS SEN PD
2009-08-03
Please read Cautions and warnings and
Page 6 of 8
Important notes at the end of this document.
EPCOS [ EPCOS ]
