Datasheet

25Maxim Integrated
±1°C Accurate 8-Channel Temperature Sensor
MAX6581
Twisted-Pair and Shielded Cables
Use a twisted-pair cable to connect the remote sensor
for remote-sensor distances longer than 8in or in very
noisy environments. Twisted-pair cable lengths can be
between 6ft and 12ft before noise introduces exces-
sive errors. For longer distances, the best solution is a
shielded twisted pair such as those used for audio micro-
phones. For example, Belden #8451 works well for dis-
tances up to 100ft in a noisy environment. At the device,
connect the twisted-pair cables to DXP_ and DXN_ and
the shielded cable to GND. Leave the shielded cable
unconnected at the remote sensor. For very long cable
runs, the cable’s parasitic capacitance often provides
noise filtering; therefore the 100pF capacitor can often
be removed or reduced in value. Cable resistance also
affects remote-sensor accuracy. For every 1I of series
resistance, the error is approximately +0.5NC.
Typical Application Circuit
DXP2 ALERT
V
CC
OVERT
STBY
DXP7
I.C.
24 23 22 21 20 19
18
17
16
15
14
13
12
DXN2
1
2
DXP1
N.C.
GND
+3.3V
SMBCLK
SMBDATA
CPU
FPGA
ASIC
100pF
100pF
DXP3
DXN3
DXN1
DXN7
3
4
5
6
100pF
100pF
100pF100pF
10 11
DXN6 DXP6
879
DXP5DXN4 DXN5
4.7kI 4.7kI4.7kI 4.7kI
TO
µP
TO
µP
TO
µP
TO
µP
0.1
µF
DXP4
N.C.
MAX6581