Texas Instruments' TMP390A ultra-low power, dual-channel, resistor-programmable temperature switcher enables protection and detection of system thermal events from -50°C to +130°C. The TMP390A offers independent overtemperature (hot) and undertemperature (cold) detection. The trip temperatures (T_TRIP) and thermal hysteresis (T_HYST) options are programmed by two E96-series (1%) standard decade value resistors on the SETA and SETB pins. Each resistor can range from 1.05 KΩ to 909 KΩ, representing one of 48 unique values.

The values of the resistor to ground on the SETA input sets the T_TRIP threshold of Channel A. The value of the resistor-to-ground on the SETB input sets the T_TRIP threshold of Channel B, as well as the T_HYST options of +5°C or +10°C for both channels preventing undesired digital output switching. The resistors accuracy has no impact on T_TRIP accuracy.

To enable customer board-level manufacturing, the TMP390 supports a trip test function where the digital outputs are activated by exercising the SETA or the SETB pin.