The LM57-Q1 device is a precision, dual-output, temperature switch with analog temperature sensor output for wide temperature applications such as automotive grade. The trip temperature (TTRIP) is selected from 256 possible values in the range of –40°C to 160°C. The VTEMPis a class AB analog voltage output that is proportional to temperature with a programmable negative temperature coefficient (NTC). Two external 1% resistors set the TTRIPand VTEMPslope. The digital and analog outputs enable protection and monitoring of system thermal events.

Built-in thermal hysteresis (THYST) prevents the digital outputs from oscillating. The TOVERandTOVERdigital outputs will assert when the die temperature exceeds TTRIPand will de-assert when the temperature falls below a temperature equal to TTRIPminus THYST.

TOVERis active-high with a push-pull structure.TOVERis active-low with an open-drain structure. Tying TOVERto TRIP-TEST will latch the output after it trips. The output can be cleared by forcing TRIP-TEST low. Driving the TRIP-TEST high will assert the digital outputs. A processor can check the state of TOVERorTOVER, confirming they changed to an active state. This allows for in situ verification that the comparator and output circuitry are functional after system assembly. When TRIP-TEST is high, the trip-level reference voltage appears at the VTEMPpin. The system could then use this voltage to calculate the threshold of the LM57-Q1.Read more