3°C Dual output resistor-programmable temperature switch with fan control

The LM56 is a precision low power thermostat. Two stable temperature trip points (VT1 and VT2) are generated by dividing down the LM56 1.250V bandgap voltage reference using 3 external resistors. The LM56 has two digital outputs. OUT1 goes LOW when the temperature exceeds T1 and goes HIGH when the the temperature goes below (T1–THYST). Similarly, OUT2 goes LOW when the temperature exceeds T2 and goes HIGH when the temperature goes below (T2–THYST). THYST is an internally set 5°C typical hysteresis.

The LM56 is available in an 8-lead VSSOP surface mount package and an 8-lead SOIC.