Microchip Technology MCP3422EV Data Sheet

© 2009 Microchip Technology Inc.

DS22088C-page 35

 shows an example of calculating the

expected number of output code with various PGA gain
settings for Type K thermocouple output.

 

 shows an example of measuring both

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

DD

 of 5V (sensor

excitation voltage). 

 shows an example of

calculating the number of output code for the full scale
output of the NPP301. 

μ

⎝

⎠

⎜

⎟

⎜

⎟

⎛

⎞

 = 11.6 bits for PGA = 1

 = 12.6 bits for PGA = 2
 = 13.6 bits for PGA = 4

 = 14.6 bits for PGA = 8

Expected
Number of Output Code = 

Where:

1 LSB

=

15.625 µV with 18 Bit configuration.

5 k

Ω

V

DD

4

5

6

9

CH2-

V

SS

CH3+

Adr1

Adr0

3

12

CH2+

CH3-

2

13

CH1-

CH4+

1

14

CH1+

CH4-

7

8

SDA

SCL

V

DD

11

10

0.1 µF

10 µF

T

O

 MCU

(MASTER)

5 k

Ω

V

DD

Thermistor

V

DD

V

DD

V

DD

V

DD

R

1

R

2

Thermistor

R

2

R

1

R

1

 and R

2

 = Voltage Divider

×

V

IN

V

IN