TMP303 Fixed Trip Point Temperature Switches Texas Instruments TMP303 Fixed Trip Point Temperature Switches offer design flexibility through an extra small footprint (SOT-563), low power (5µA maximum) and low supply voltage capability (as low as 1.4V). These devices require no additional components for operation and each can function independently of microprocessors or microcontrollers. The trip points are preprogrammed at the factory. The OUT pin is a push-pull, active-high output. When the measured temperature is beyond the trip point range and the Set Output High (SOH) pin is low, the OUT pin is high. The SOH pin is an input pin with an internal pulldown resistor. When the SOH pin is forced high, the OUT pin goes high regardless of the measured temperature.