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 VTEMP is a class AB analog voltage
output that is proportional to temperature with a programmable negative temperature coefficient
(NTC). Two external 1% resistors set the TTRIP and
VTEMP slope. 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 TOVER and
digital outputs will assert when the die temperature
exceeds TTRIP and will de-assert when the temperature falls below a
temperature equal to TTRIP minus THYST.
TOVER is active-high with a push-pull structure.
is active-low with an open-drain structure. Tying
TOVER to 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 TOVER or
, 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
VTEMP pin. The system could then use this voltage to calculate the threshold
of the LM57-Q1.
View datasheet View product folder