MCP3424 Microchip Technology, MCP3424 Datasheet - Page 34

• Manufacturer Part Number: MCP3424
• Description: Multi-Channel Analog-to-Digital Converter
• Manufacturer: Microchip Technology

MCP3422/3/4
Figure
MCP3424 for four-channel thermocouple temperature
measurement applications.
FIGURE 6-6:
With
temperature from 0°C to 1250°C degrees. The full
scale output range of the Type K thermocouple is
about 50 mV. This provides 40 µV/°C (= 50 mV/
1250°C) of measurement resolution.
shows the measurement budget for sensor signal using
the
PGA = 8 settings.
MCP3424 can detect the input signal level as low as
approximately 2 µV. The internal PGA boosts the input
signal level eight times. The 40 µV/°C input from the
thermocouple is amplified internally to 320 µV/°C
before the conversion takes place. This results in
20.48 LSB/°C output codes. This means there are
about 20 LSB output codes (or about 4.32 bits) per 1°C
of change in temperature.
DS22088C-page 34
Thermocouple Sensor
Heat
MCP3422/3/4
6-6,
Type
shows
K
thermocouple,
MCP9800
MCP9800
With
an
Four-Channel Thermocouple Applications.
device
Isothermal Block
SDA
example
SCL
this
SDA
SCL
with
configuration,
it
of
can
0.1 µF
18 bits
Equation 6-1
10 µF
using
measure
1
2
3
4
5
6
7
SDA
and
CH1+
CH2+
5 kΩ
CH1-
SDA
CH2-
V
V
the
the
SS
DD
MCP3424
CH4+
CH3+
CH4-
CH3-
Adr1
Adr0
SCL
EQUATION 6-1:
Where:
Detectable Input Signal Level
Input Signal Level after gain of 8:
14
13
12
11
10
1 LSB
9
8
No. of LSB/°C
SCL
5 kΩ
(MASTER)
T
O
MCU
V
V
=
DD
DD
15.625 µV with 18 bit configuration
SDA
=
SDA
Isothermal Block
320
------------------------ -
=
15.625
SCL
MCP9800
MCP9800
=
© 2009 Microchip Technology Inc.
(
μ
40
SCL
1.953125
V/°C
μ
μ
V/°C
V
=
=
15.625
) 8
μ
20.48 Codes/°C
•
V for PGA
=
μ
V/PGA
320
www.DataSheet4U.com
μ
V/°C
=
8