MCP3422A1-E/MS Microchip Technology, MCP3422A1-E/MS Datasheet - Page 35

• Manufacturer Part Number: MCP3422A1-E/MS
• Description: 18-Bit, Multi-Channel Delta-Sigma ADC w/ I2C Interface and On-Board Reference ; 8L MSOP 3x3mm
• Manufacturer: Microchip Technology

Equation 6-2
expected number of output code with various PGA gain
settings for Type K thermocouple output.
EQUATION 6-2:
FIGURE 6-7:
Figure 6-7
pressure and temperature. The pressure is measured
by using NPP 301 (manufactured by GE NovaSensor),
and temperature is measured by a thermistor. The
pressure sensor output is 20 mV/V. This gives 100 mV
of full scale output for V
© 2008 Microchip Technology Inc.
Where:
Expected
Number of Output Code =
1 LSB = 15.625 µV with 18 Bit configuration.
Thermistor
shows an example of measuring both
shows an example of calculating the
V
DD
V
R
DD
R
1
2
Pressure Sensor
EXPECTED NUMBER OF
OUTPUT CODE FOR TYPE
K THERMOCOUPLE
Example of Pressure and Temperature Measurement.
DD
(NPP301)
of 5V (sensor excitation volt-
= 11.6 bits for PGA = 1
= 12.6 bits for PGA = 2
= 13.6 bits for PGA = 4
= 14.6 bits for PGA = 8
log
0.1 µF
2
V
⎛
⎜
⎜
⎝
10 µF
IN
----------------------- -
15.625μV
----------------------- -
50 mV
PGA
V
R
IN
1
1
2
3
4
5
6
7
5 kΩ
⎞
⎟
⎟
⎠
and R
CH1+
CH1-
CH2+
CH2-
V
V
SDA
=
SS
DD
MCP3424
------------------
R
2
1
R
= Voltage Divider
+
2
R
2
CH4+
CH3+
CH4-
CH3-
Adr1
Adr0
×
SCL
V
age).
the number of output code for the full scale output of the
NPP301.
DD
5 kΩ
13
10
14
12
11
9
8
Equation 6-3
V
IN
V
DD
(MASTER)
V
T
DD
O
shows an example of calculating
MCP3422/3/4
MCU
V
DD
R
R
2
1
Pressure Sensor
V
DD
DS22088B-page 35
(NPP301)
Thermistor