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.