19-2138; Rev 1; 12/03
High-Accuracy PWM Output Temperature
Sensors
General Description
The MAX6666/MAX6667 are high-accuracy, low-cost,
low-power temperature sensors with a single-wire
output. The MAX6666/MAX6667 convert the ambient
temperature into a ratiometric PWM output with temper-
ature information contained in the duty cycle of the out-
put square wave. The MAX6666 has a push-pull output
and the MAX6667 has an open-drain output.
The MAX6666/MAX6667 operate at supply voltages
from +3V to +5.5V. The typical unloaded supply current
at 5.0V is 200碌A(chǔ). Both devices feature a single-wire
output that minimizes the number of pins necessary to
interface with a microprocessor (碌P). The output is a
square wave with a nominal frequency of 35Hz (鹵20%)
at +25擄C. The output format is decoded as follows:
Temperature (擄C) = 235 - (400 x t
1
) / t
2
Where t
1
is fixed with a typical value of 10ms and t
2
is
modulated by the temperature (Figure 1). The
MAX6666/MAX6667 operate from -40擄C to +125擄C and are
available in space-saving SOT23 and 碌MAX packages.
o
Simple Single-Wire PWM Output
o
鹵1.0擄C Accuracy at +25擄C
o
High Accuracy
鹵1擄C at T
A
= +30擄C
鹵2.5擄C at T
A
= +10擄C to +50擄C
o
Operate Up to +125擄C
o
Low 200碌A(chǔ) Typical Current Consumption
o
Multiple Package Options
6-Pin SOT23
8-Pin SO
8-Pin 碌MAX
Features
MAX6666/MAX6667
Ordering Information
PART
MAX6666AUT-T
MAX6666AUA
MAX6666ASA
MAX6667AUT-T
MAX6667AUA
MAX6667ASA
TEMP RANGE
-40擄C to +125擄C
-40擄C to +125擄C
-40擄C to +125擄C
-40擄C to +125擄C
-40擄C to +125擄C
-40擄C to +125擄C
PIN-PACKAGE
6 SOT23-6
8 碌MAX
8 SO
6 SOT23-6
8 碌MAX
8 SO
Applications
Process Control
Industrial
HVAC and Environmental Control
Automotive
碌P and 碌C Temperature Monitoring
Typical Operating Circuit
+3.3V
V
CC
t
1
t
2
Pin Configurations
TOP VIEW
D
OUT
V
CC
1
2
3
8
7
IC
IC
IC
IC
MAX6666
MAX6667
DOUT
GND
碌C
INPUT TO
TIMER/COUNTER
GND
MAX6666
MAX6667
6
5
IC
4
碌MAX/SO
Pin Configurations continued at end of data sheet.
________________________________________________________________
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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