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 temperature
information contained in the duty cycle of the output
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 200μA. Both devices feature a single-wire
output that minimizes the number of pins necessary to
interface with a microprocessor (μP). The output is a
square wave with a nominal frequency of 35Hz (±20%)
at +25°C. The output format is decoded as follows:
Temperature (°C) = 235 - (400 x t1) / t2
Where t1 is fixed with a typical value of 10ms and t2 is
modulated by the temperature (Figure 1). The MAX6666/
MAX6667 operate from -40°C to +125°C and are available
in space-saving SOT23 packages.
Applications
Process Control
Industrial
HVAC and Environmental Control
Automotive
μP and μC Temperature Monitoring