High-Accuracy PWM Output Temperature Sensors

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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 × t1)/t2
Where t1 is fixed with a typical value of 10ms and t2 is modulated by the temperature (Figure 1 in the full data sheet). The MAX6666/MAX6667 operate from -40° to +125° and are available in space-saving SOT23 packages.
MAX6666, MAX6667: Typical Operating Circuit MAX6666, MAX6667: Typical Operating Circuit Enlarge+

Key Features

  • Simple Single-Wire PWM Output
  • ±1.0°C Accuracy at +25°C
  • High Accuracy
    • ±1°C at TA = +30°C
    • ±2.5°C at TA = +10°C to +50°C
  • Operate Up to +125°C
  • Low 200µA Typical Current Consumption
  • Small SOT23 package


  • HVAC and Environmental Control
  • Industrial
  • Process Control
  • µP and µC Temperature Monitoring

Additional Resources

Temperature Family by Product Type
Request Reliability Report for: MAX6666 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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