Data Sheet

MCP3422/3/4
DS22088C-page 36 © 2009 Microchip Technology Inc.
EQUATION 6-3: EXPECTED NUMBER OF
OUTPUT CODE FOR
NPP301 PRESSURE
SENSOR
The thermistor temperature sensor can measure the
temperature range from -100°C to 300°C. The
resistance of the thermistor sensor decreases as
temperature increases (negative temperature
coefficient). As shown in Figure 6-7, the thermistor (R
2
)
forms a voltage divider with R
1
.
The thermistor sensor is simple to use and widely used
for the temperature measurement applications. It has
both linear and non-linear responses over temperature
range. R
1
is used to adjust the linear region of interest
for measurement.
Expected
log
2
100 mV
15.625
μ V
PGA
------------------------
------------------------
⎝⎠
⎜⎟
⎜⎟
⎛⎞
= 12.64 bits for PGA = 1
= 13.64 bits for PGA = 2
= 14.64 bits for PGA = 4
= 15.64 bits for PGA = 8
Number of Output Code =
Where:
1 LSB = 15.625 µV with 18 Bit configuration.