Datasheet
Package Availability, Models, Samples & Pricing
| Part Number | Package | Factory Lead Time | Models | Samples & Electronic Orders | Budgetary Pricing | Std Pack Size | Package Marking Format |
| Type | Pins | Spec. | MSL Rating | Peak Reflow | RoHS Report | CAD Symbols | Weeks | Qty | Qty | $US each |
| LM57B10EB | LM57 Evaluation Board | Full production | N/A
|
| 1+ | $65.00 | 1 | - |
| N/A | N/A |
| LM57BISD-10 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
| 
| 1K+ | $1.25 | reel of 1000 | XYTT 57B9 |
| 12 weeks | 1000 |
| LM57BISD-5 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
| 
| 1K+ | $1.25 | reel of 1000 | XYTT 57B5 |
| 12 weeks | 2000 |
| LM57CISD-10 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
| 
| 1K+ | $0.89 | reel of 1000 | XYTT 57C9 |
| 6 weeks | 2000 |
| LM57CISD-5 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
| 
| 1K+ | $0.89 | reel of 1000 | XYTT 57C5 |
| 6 weeks | 1000 |
| LM57BISDX-10 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
|
| 1K+ | $1.25 | reel of 4500 | XYTT 57B9 |
| 12 weeks | N/A |
| LM57BISDX-5 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
|
| 1K+ | $1.25 | reel of 4500 | XYTT 57B5 |
| 12 weeks | N/A |
| LM57CISDX-10 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
|
| 1K+ | $0.89 | reel of 4500 | XYTT 57C9 |
| 12 weeks | N/A |
| LM57CISDX-5 | LLP | 8 | NOPB | 3 | 260 | RoHS |
N/A |
Full production | N/A
|
| 1K+ | $0.89 | reel of 4500 | XYTT 57C5 |
| 12 weeks | N/A |
General Description
The LM57 is a precision, dual-output, temperature switch with integrated analog temperature sensor. The trip temperature
(TTRIP) is programmable by using two external 1% resistors. Using extremely small packaged resistors (0.5 mm x 1 mm), the LM57 can
be programmed to any of 256 trip temperatures while consuming very little board space. The VTEMP output delivers an analog output voltage which is proportional with a negative temperature coefficient (NTC) to the measured
temperature.
Built-in temperature hysteresis (THYST) keeps the output stable in an environment of thermal oscillation. The digital temperature switch outputs will go active
when the die temperature exceeds TTRIP and will release when the temperature falls below a temperature equal to TTRIP minus THYST. One of the digital outputs, TOVER, is active-high with a push-pull structure. The other digital output,
^TOVER, is active-low with an open-drain structure.
Driving the TRIP-TEST input high will make the digital outputs active. A processor can read the logic level of the temperature
switch outputs, confirming that they changed to their active state. This allows for in-situ verification that the comparator
and output circuitry are functional after system assembly. When the TRIP-TEST pin is high, the trip-level reference voltage
appears at the Vtemp pin. The system could then use this voltage to calibrate the sensor for even tighter accuracy. Tying
TOVER to TRIP-TEST will latch the output after it trips. It can be cleared by forcing TRIP-TEST low or powering off the LM57.
As it draws only 28µA max from its supply, it has very low self-heating, about 0.02°C in still air.
Application Notes
| Title | Size in Kbytes |
Date |
 |
| AN-1984: Application Note 1984 LM57 Temperature Switch vs Thermistors |
210 Kbytes |
28-Jul-09 |
Download |
[Information as of 7-Nov-2009]
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