LTC2983
50
2983fc
For more information www.linear.com/LTC2983
APPLICATIONS INFORMATION
Example: Shared/Rotated Differential Thermistor
The differential thermistor configuration allows separate
internal ground sensing for each sensor. In this configura-
tion, one sense resistor can be used for multiple thermis-
tors. Differential thermistors follow the convention shown
in Figure 28. Terminal 1 ties to CH
THERM
and terminal 2
ties to CH
THERM-1
and the sense resistor. Channel assign-
ment data (see Table 50) is mapped to memory locations
corresponding to CH
THERM
.
Sense resistor channel assignments follow the general
convention shown in Figure 29. The sense resistor is tied
between CH
RSENSE
and CH
RSENSE-1
, where CH
SENSE
is tied
to the 2nd terminal of the thermistor. Channel assignment
data (see Table 33) is mapped into a memory location
corresponding to CH
THERM
.
Figure 30 shows a typical temperature measurement
system using a shared sense resistor and one rotated/
one non-rotated differential thermistors. In this example
Figure 28. Thermistor with Shared R
SENSE
Channel
Assignment Convention
Figure 29. Sense Resistor Channel Assignment
Convention for Thermistors
2983 F28
2
1
CH
THERM–1
CH
THERM
EXCITATION
CURRENT
FLOW
= CH
THERM
(2 ≤ THERM ≤ 20)
2ND TERMINAL TIES TO SENSE RESISTOR
CHANNEL
ASSIGNMENT
2983 F29
CH
RSENSE-1
CH
RSENSE
R
SENSE
EXCITATION
CURRENT
FLOW
= CH
RSENSE
(2 ≤ RSENSE ≤ 20)
CHANNEL
ASSIGNMENT
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