Linear Technology DC2531 Demo Manual page 10

DEMO MANUAL DC2531
HarDware setup
DC2212 ThErMoCoupLE DaughTEr BoarD
The thermocouple board (see Figure 9) demonstrates the
flexibility, accuracy, and low noise features of the LTC2986
thermocouple modes.
If the user wishes to connect external sensors to the
thermocouple board, two universal-type thermocouple
jacks (J2 and J3) are provided (see schematic diagram
Figure 10 and corresponding software configuration
Figure 11). The user may connect any of the LTC2986
supported thermocouples (B, E, J, K, N, R, S, or T) as well
as custom thermocouples through these jacks.
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To demonstrate the flexibility of the LTC2986, the thermo-
couple board includes cold junction diodes (Q1 and Q2)
embedded in each thermocouple socket. Alternatively, a
4-wire PT100 RTD (R5) can be used as the cold junction
sensor for either or both thermocouples.
To demonstrate the low system noise and offset of the
LTC2986, the thermocouple board provides a short to
ground on channel 5.
To demonstrate the accuracy of the LTC2986, the thermo-
couple board allows the user to connect a thermocouple
calibrator or an external voltage source to CH10 of the
LTC2986 through a pair of banana jacks (J4 and J5).
Figure 9. DC2212 Thermocouple Daughter Board
dc2531f