1 Features
1• Qualified for Automotive Applications, for
Commercial Device See LM57 Data Sheet
• AEC-Q100 Qualified with the Following Results:
– Temperature Grade 0 Extended: −50°C to
+160°C with Excursions up to 170°C Operating
Temperature Range
– Temperature Grade 0: −50°C to +150°C
Operating Temperature Range
– Temperature Grade 1: −50°C to +125°C
Operating Temperature Range
– HBM ESD Component Classification Level 2
– CDM ESD Component Classification Level C5
• Trip Temperature Set by External Resistors with
Accuracy of ±2.3°C from −40°C to +150°C
• Resistor Tolerance Contributes Zero Error
• Push-Pull and Open-Drain Switch Outputs
• Wide Operating Temperature Range of −50°C to
160°C
• Very Linear Analog VTEMP Temp Sensor Output
with ±1.3°C Accuracy from −50°C to +150°C
• Short-Circuit Protected Analog and Digital Outputs
• Latching Function for Digital Outputs
• TRIP-TEST Pin Allows In-System Testing
• Low Power Minimizes Self-Heating to Under
0.02°C

2 Applications
• Automotive
• Down Hole and Avionics

3 Description
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 TOVER 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. TOVER
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
TOVER , 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.