MAX6666

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 200µA. Both devices feature a single-wire output that minimizes thenumber of pins necessary to interface with a microprocessor (µP). The output is asquare wave with a nominal frequency of 35Hz (±20%)at +25°C. The output format is decoded as follows: Temperature (°C) = 235 - (400 x t1) / t²Where t ¹is fixed with a typical value of 10ms and t²is modulated by the temperature (Figure 1). The MAX6666/MAX6667 operate from -40°C to +125°C and are available in space-saving SOT23 and µMAX packages.