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.
The MAX6666 and MAX6667 convert ambient temperature to a ratiometric PWM output. The MAX6666 provides a push‑pull output, while the MAX6667 uses an open‑drain output. Both devices operate from +3 V to +5.5 V and are available in a 6‑pin SOT23 package.
Typical applications include process control, HVAC, automotive temperature monitoring, and microcontroller‑based temperature sensing. Features include ±1 °C accuracy at 25 °C, low 200 nA typical supply current, and a nominal 35 Hz output frequency.
| Supply Voltage Range | 3.0 V to 5.5 V |
|---|---|
| Output Frequency (nominal) | 35 Hz ±20 % |
| Operating Temperature Range | -40 °C to +125 °C |
| Package | 6‑pin SOT23 |
| Accuracy at 25 °C | ±1.0 °C |
They operate from 3.0 V to 5.5 V.
The MAX6666 has a push‑pull output, while the MAX6667 has an open‑drain output.
Accuracy is ±1 °C at 25 °C and ±2.5 °C from 10 °C to 50 °C.