Datasheet

26 LMP90100 EVB User’s Guide August 2012
Figure 23 - Recommended LMP90100 Configuration for a Thermocouple
1. Step 1: Select a Sensor - select “Thermocouple”  select the thermocouple of your choice
or add your own thermocouple by clicking on “New”.
2. Step 2: Configure Inputs – click on the “INPUT MUX” block to set “VINP = 100: VIN4”
and “VINN = 011: VIN3”. Click on the “Eval. Board Settings button located next to the
block diagram. This should open up a PDF of the schematic for a thermocouple.
3. Step 3: Source IB1/IB2? – this step can be ignored because neither IB1 nor IB2 is connected
to the inputs.
4. Step 4: Select Reference – click on the “VREF MUX” block to choose “VREF_SEL = 0:
VREF1”. Make sure the value for VREF1 = 4.1V.
5. Step 5: Set Gain – since the differential junction across a thermocouple is low, the maximum
gain can be 128x. Click on the “FGA” block, “PGA” block, or the “Gain” slider to select
the gain. In this example, the gain can be 1x.
6. Step 6: Set Buffer – click on the “ B U F F” block to include or exclude the buffer from the
signal path. The buffer can be excluded from the signal path in this example.
7. Step 7: Set Calibration - click on the “No Calibration” block to enable or disable calibration.
Refer to the LMP90100 datasheet to more information on the LMP90100’s background
calibration types and modes. In this example, the calibration can be OFF.