19-2459; Rev 1; 1/03
Dual-Output Remote-Junction
Temperature Switches
General Description
MAX6685/MAX6686 are dual-output temperature switches
that use an external diode-connected transistor as a sens-
ing element. These devices have two logic outputs (T
HIGH
and T
LOW
). T
HIGH
asserts a logic signal when the remote
temperature crosses the factory-programmed, +120擄C, or
+125擄C upper trip threshold. T
LOW
is asserted when the
remote temperature exceeds the lower threshold, which is
controlled by pins S1 and S2. The lower thresholds are
available in two ranges in 5擄C increments. The two ranges
are +40擄C to +80擄C and +75擄C to +115擄C. Hysteresis for
both outputs to be deasserted is typically 5擄C.
T
HIGH
is an open-drain, active-low output for both the
MAX6685 and the MAX6686. T
LOW
is a CMOS push-pull,
active-high output for the MAX6685 and is an open-drain,
active-low output for the MAX6686. They are available in
a space-saving 8-pin 碌MAX package.
Features
o
Pin-Programmed Lower Temperature Threshold
from +40擄C to +80擄C or +75擄C to +115擄C
(5擄C Increments)
o
Preset Upper Threshold: +120擄C or +125擄C
o
Open-Drain, Active-Low Output for Upper
Temperature Alarm
o
CMOS Push-Pull, Active-High or Open-Drain,
Active-Low Output for Lower Temperature Alarm
o
1.5擄C Accuracy
o
3.0V to 5.5V, 200碌A(chǔ) Supply
o
8-Pin 碌MAX Package
MAX6685/MAX6686
Applications
CPU Temperature
Protection
Fan Control
Multichip Modules
FPGA Temperature
Protection
Pin Configurations appear at end of data sheet.
Ordering Information
PART
MAX6685UA40L
MAX6685UA40H
MAX6685UA75L
MAX6685UA75H
MAX6686UA40L
MAX6686UA40H
MAX6686UA75L
MAX6686UA75H
T
LOW
OUTPUT
Push-pull, active high
Push-pull, active high
Push-pull, active high
Push-pull, active high
Open drain, active low
Open drain, active low
Open drain, active low
Open drain, active low
T
LOW
TRIP
RANGE (0擄C)
+40擄C to +80擄C
+40擄C to +80擄C
+75擄C to +115擄C
+75擄C to +115擄C
+40擄C to +80擄C
+40擄C to +80擄C
+75擄C to +115擄C
+75擄C to +115擄C
T
HIGH
TRIP
THRESHOLD (0擄C)
+120擄C
+125擄C
+120擄C
+125擄C
+120擄C
+125擄C
+120擄C
+125擄C
PIN-PACKAGE
8 碌MAX
8 碌MAX
8 碌MAX
8 碌MAX
8 碌MAX
8 碌MAX
8 碌MAX
8 碌MAX
Typical Operating Circuits
3.3V
V
DD
TO SYSTEM
SHUTDOWN
T
HIGH
12V
CPU
C
S
DXN
S1
T
LOW
GND
N
S2
GND
T
LOW
DXP
3.3V
V
DD
CPU
C
S
DXP
T
HIGH
TO SYSTEM
SHUTDOWN
MAX6685
DXN
S1
S2
MAX6686
TO CLOCK
THROTTLE
CONTROL
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim鈥檚 website at www.maxim-ic.com.
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