Datasheet
MCP9600
DS20005426C-page 24 2015-2017 Microchip Technology Inc.
5.1 Thermocouple Temperature
Sensor Registers
This device integrates three Temperature registers that
are used to read the cold and hot-junction temperatures,
and the sum of the two junctions to output the absolute
thermocouple temperature. In addition, the Raw ADC
Data register, which is used to derive the thermocouple
temperature, is available. The following sections
describe each register in detail.
5.1.1 THERMOCOUPLE TEMPERATURE
REGISTER (T
H
)
This register contains the cold-junction compensated and
error-corrected thermocouple temperature in degree
Celsius. The temperature data from this register is the
absolute Thermocouple Hot-Junction temperature, T
H
, to
the specified accuracy (see Section 1.0 “Electrical
Characteristics”. T
H
is the sum of the values in the T
∆
and T
C
registers, as shown in Figure 5-2.
EQUATION 5-1: TEMPERATURE
CONVERSION
The temperature bits are in two’s complement format;
therefore, positive temperature data and negative tem-
perature data are computed differently. Equation 5-1
shows how to convert the binary data to temperature in
degree Celsius.
FIGURE 5-2: Thermocouple Temperature
Register Block Diagram.
Temperature 0°C
T
H
= (UpperByte x 16 + LowerByte/16)
Temperature 0°C
T
H
= (UpperByte x 16 + LowerByte/16) – 4096
V
IN
+
V
IN
-
Temperature
Sensor Core
ADC Core
Delta-Sigma
18-Bit
Error Corrected
Temperature
ADC
Thermocouple
Temperature
T
C
T
H
T
∆
REGISTER 5-2: THERMOCOUPLE TEMPERATURE REGISTER (READ-ONLY)
R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0
SIGN 1024°C 512°C 256°C 128°C 64°C 32°C 16°C
bit 15 bit 8
R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0
8°C 4°C 2°C 1°C 0.5°C 0.25°C 0.125°C 0.0625°C
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 15 SIGN: Sign bit
1 =T
A
0°C
0 =T
A
0°C
bit 14-0 T
H
: Data in Two’s Complement Format bits
This register contains the error corrected and cold-junction compensated thermocouple temperature.