3–446
Motorola Sensor Device Data
For More Information On This Product,
Go to: www.freescale.com
Symbols, Terms and Definitions
The following are the most commonly used letter symbols, terms and definitions associated with solid state silicon pressure
sensors.
Pburst
Burst Pressure
The maximum pressure that can be applied to a transducer without rupture of either the sensing
element or transducer case.
Io
Io+
kPa
supply current
The current drawn by the sensor from the voltage source.
output source current
The current sourcing capability of the pressure sensor.
kilopascals
Unit of pressure. 1 kPa = 0.145038 PSI.
—
Linearity
The maximum deviation of the output from a straight line relationship with pressure over the
operating pressure range, the type of straight line relationship (end point, least square
approximation, etc.) should be specified.
mm Hg
millimeters of mercury
Unit of pressure. 1 mmHg = 0.0193368 PSI.
Pmax
overpressure
The maximum specified pressure which may be applied to the sensing element without
causing a permanent change in the output characteristics.
POP
operating pressure range
The range of pressures between minimum and maximum temperature at which the output
will meet the specified operating characteristics.
—
Pressure Hysteresis
The difference in the output at any given pressure in the operating pressure range when
this pressure is approached from the minimum operating pressure and when approached
from the maximum operating pressure at room temperature.
PSI
pounds per square inch
Unit of pressure. 1 PSI = 6.89473 kPa.
—
Repeatability
The maximum change in output under fixed operating conditions over a specified period of
time.
Ro
input resistance
The resistance measured between the positive and negative input terminals at a specified
frequency with the output terminals open.
TA
TCR
operating temperature
The temperature range over which the device may safely operate.
temperature coefficient
of resistance
The percent change in the DC input impedance per unit change in temperature relative to the
DC input impedance at a specified temperature (typically +25
°
C).
TCVFSS
temperature coefficient
of full scale span
The percent change in full scale span per unit change in temperature relative to the full scale
span at a specified temperature (typically +25
°
C).
TCVoff
temperature coefficient
of offset
The percent change in offset per unit change in temperature relative to the offset at a speci-
fied temperature (typically +25
°
C).
Tstg
tR
storage temperature
The temperature range at which the device, without any power applied, may be stored.
response time
The time required for the incremental change in the output to go from 10% to 90% of its
final value when subjected to a specified step change in pressure.
—
Temperature Hysteresis
The difference in output at any temperature in the operating temperature range when the
temperature is approached from the minimum operating temperature and when approached
from the maximum operating temperature with zero pressure applied.
VFSS
Voff
VS
full scale span voltage
The change in output over the operating pressure range at a specified supply voltage.
offset voltage
The output with zero differential pressure applied for a specified supply voltage or current.
supply voltage dc
The dc excitation voltage applied to the sensor. For precise circuit operation, a regulated
supply should be used.
VS max
Zin
maximum supply voltage
The maximum supply voltage that may be applied to a circuit or connected to the sensor.
input impedance
The resistance measured between the positive and negative input terminals at a specified
frequency with the output terminals open. For Motorola X-ducer, this is a resistance measure-
ment only.
Zout
output impedance
The resistance measured between the positive and negative output terminals at a speci-
fied frequency with the input terminals open.
V/
P
sensitivity
The change in output per unit change in pressure for a specified supply voltage.
F
Freescale Semiconductor, Inc.
n
.