Texas Instruments' TMP709 is a fully-integrated, resistor- programmable temperature switch with a temperature threshold that is set by just one external resistor within its entire operating range. The TMP709 provides an open-drain, active-low output and has a 2.7 V to 5.5 V supply voltage range.
The temperature threshold accuracy is typically ±0.5°C with a maximum of ±3°C (+60°C to +100°C). The quiescent current consumption is typically 40 µA. Hysteresis is pin-selectable to 2°C or 10°C.