Packaging information
| Package | Pins TSSOP (PW) | 8 |
| Operating temperature range (°C) -50 to 150 |
| Package qty | Carrier 2,000 | LARGE T&R |
Features for the LM57
- See LM57-Q1 datasheet for AEC-Q100 Grade 1/Grade 0/Grade 0 Extended (Qualified and Manufactured on an Automotive Grade Flow)
- Trip Temperature Set by External Resistors with
Accuracy of ±1.7°C or ±2.3°C from -40°C to +150°C - Resistor Tolerance Contributes Zero Error
- Push-Pull and Open-Drain Switch Outputs
- Wide Operating Temperature and Trip-Temperature Range of −50°C to 150°C,
- Very Linear Analog VTEMP Temp Sensor Output
with ±0.8°C or ±1.3°C Accuracy from -40°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
Description for the LM57
The LM57 device is a precision, dual-output, temperature switch with analog temperature sensor output for wide temperature industrial applications. The trip temperature (TTRIP) is selected from 256 possible values in the range of –40°C to +150°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.