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  • LM50 and LM50-Q1 SOT-23 Single-Supply Centigrade Temperature Sensor

    • SNIS118G July   1999  – January 2017 LM50 , LM50-Q1

      PRODUCTION DATA.  

  • CONTENTS
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  • LM50 and LM50-Q1 SOT-23 Single-Supply Centigrade Temperature Sensor
  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics: LM50B
    6. 6.6 Electrical Characteristics: LM50C and LM50-Q1
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 LM50 and LM50-Q1 Transfer Function
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Full-Range Centigrade Temperature Sensor
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Capacitive Loads
        3. 8.2.1.3 Application Curve
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
  13. IMPORTANT NOTICE

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
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Thermal pad, mechanical data (Package|Pins)
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DATA SHEET

LM50 and LM50-Q1 SOT-23 Single-Supply Centigrade Temperature Sensor

1 Features

  • LM50-Q1 is AEC-Q100 Grade 1 Qualified and is Manufactured on an Automotive Grade Flow
  • Calibrated Directly in Degrees Celsius (Centigrade)
  • Linear + 10 mV/°C Scale Factor
  • ±2°C Accuracy Specified at 25°C
  • Specified for Full –40° to 125°C Range
  • Suitable for Remote Applications
  • Low Cost Due to Wafer-Level Trimming
  • Operates From 4.5 V to 10 V
  • Less Than 130-µA Current Drain
  • Low Self-Heating: Less Than 0.2°C in Still A
  • Nonlinearity Less Than 0.8°C Over Temp
  • UL Recognized Component

2 Applications

  • Automotive
  • Computers
  • Disk Drives
  • Battery Management
  • FAX Machines
  • Printers
  • Portable Medical Instruments
  • HVAC
  • Power Supply Modules

    • SPACER

3 Description

The LM50 and LM50-Q1 devices are precision integrated-circuit temperature sensors that can sense a –40°C to 125°C temperature range using a single positive supply. The output voltage of the device is linearly proportional to temperature (10 mV/°C) and has a DC offset of 500 mV. The offset allows reading negative temperatures without the need for a negative supply.

The ideal output voltage of the LM50 or LM50-Q1 ranges from 100 mV to 1.75 V for a –40°C to 125°C temperature range. The LM50 and LM50-Q1 do not require any external calibration or trimming to provide accuracies of ±3°C at room temperature and ±4°C over the full –40°C to 125°C temperature range. Trimming and calibration of the LM50 and LM50-Q1 at the wafer level assure low cost and high accuracy. The linear output, 500 mV offset, and factory calibration of the LM50 and LM50-Q1 simplify the circuitry requirements in a single supply environment where reading negative temperatures is necessary. Because the quiescent current of the LM50 and LM50-Q1 is less than 130 µA, self-heating is limited to a very low 0.2°C in still air.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM50, LM50-Q1 SOT-23 (3) 2.92 mm × 1.30 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

LM50 LM50-Q1 full_range_centigrade_temp_sensor_snis118.gif

Full-Range Centigrade Temperature Sensor (–40°C to 125°C)

LM50 LM50-Q1 C001_SNIS177.png

4 Revision History

Changes from F Revision (December 2016) to G Revision

  • Changed LMT90 to LM50 in VO description of Equation 1 Go

Changes from E Revision (September 2013) to F Revision

  • Added Device Information table, Pin Configuration and Functions section, ESD Ratings table, Detailed Description section, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo
  • Added Thermal Information tableGo
  • Changed Junction-to-ambient, RθJA, value in Thermal Information table From: 450°C/W To: 291.9°C/WGo
  • Deleted the Temperature To Digital Converter (Parallel TRI-STATE Outputs for Standard Data Bus to µP Interface) (125°C Full Scale) figureGo

Changes from C Revision (February 2013) to E Revision

  • Added LM50-Q1 option throughout documentGo

5 Pin Configuration and Functions

DBZ Package
3-Pin SOT-23
Top View
LM50 LM50-Q1 PinOut_DBZ-3_SNIS118.gif

Pin Functions

PIN TYPE DESCRIPTION
NO. NAME
1 +VS Power Positive power supply pin.
2 VOUT Output Temperature sensor analog output.
3 GND Ground Device ground pin, connected to power supply negative terminal.

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Supply voltage –0.2 12 V
Output voltage –1 +VS + 0.6 V
Output current 10 mA
Maximum junction temperature, TJ 150 °C
Storage temperature, Tstg –65 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

6.2 ESD Ratings

VALUE UNIT
LM50
V(ESD) Electrostatic discharge Human body model (HBM)(1) ±2000 V
Charged-device model (CDM) ±750
Machine model(1) ±250
LM50-Q1
V(ESD) Electrostatic discharge Human-body model (HBM), per AEC Q100-002(2) ±2000 V
Charged-device model (CDM), per AEC Q100-011 ±750
(1) The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin. Machine model is a 200-pF capacitor discharged directly into each pin.
(2) AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.

6.3 Recommended Operating Conditions(1)

MIN MAX UNIT
+VS Supply voltage 4.5 10 V
TMIN, TMAX Specified temperature LM50C, LM50-Q1 –40 125 °C
LM50B –25 100
Operating temperature –40 150 °C
(1) Soldering process must comply with the Reflow Temperature Profile specifications. Reflow temperature profiles are different for lead-free and non-lead-free packages. Refer to www.ti.com/packaging.

6.4 Thermal Information

THERMAL METRIC(1) LM50, LM50-Q1 UNIT
DBZ (SOT-23)
3 PINS
RθJA Junction-to-ambient thermal resistance 291.9 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 114.3 °C/W
RθJB Junction-to-board thermal resistance 62.3 °C/W
φJT Junction-to-top characterization parameter 7.4 °C/W
φJB Junction-to-board characterization parameter 61 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics: LM50B

+VS = 5 V (DC) and ILOAD = 0.5 µA, in the circuit of Figure 12, TA = TJ = 25°C (unless otherwise noted)(1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Accuracy(2) TA = 25°C –2 2 °C
TA = TMAX –3 3 °C
TA = TMIN –3.5 3 °C
Nonlinearity(3) TA = TJ = TMIN to TMAX –0.8 0.8 °C
Sensor gain (average slope) TA = TJ = TMIN to TMAX 9.7 10.3 mV/°C
Output resistance TA = TJ = TMIN to TMAX 2000 4000 Ω
Line regulation(4) +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX –1.2 1.2 mV/V
Quiescent current(5) +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX 180 µA
Change of quiescent current +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX 2 µA
Temperature coefficient of quiescent current TA = TJ = TMIN to TMAX 1 µA/°C
Long term stability(6) TJ = 125°C, for 1000 hours ±0.08 °C
(1) Limits are specified to TI's AOQL (Average Outgoing Quality Level).
(2) Accuracy is defined as the error between the output voltage and 10 mv/°C multiplied by the device's case temperature plus 500 mV, at specified conditions of voltage, current, and temperature (expressed in °C).
(3) Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device's rated temperature range.
(4) Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output due to heating effects can be computed by multiplying the internal dissipation by the thermal resistance.
(5) Quiescent current is defined in the circuit of Figure 12.
(6) For best long-term stability, any precision circuit will give best results if the unit is aged at a warm temperature, and/or temperature cycled for at least 46 hours before long-term life test begins. This is especially true when a small (Surface-Mount) part is wave-soldered; allow time for stress relaxation to occur. The majority of the drift occurs in the first 1000 hours at elevated temperatures. The drift after 1000 hours does not continue at the first 1000 hour rate.

6.6 Electrical Characteristics: LM50C and LM50-Q1

+VS = 5 V (DC) and ILOAD = 0.5 µA, in the circuit of Figure 12. TA = TJ = 25°C, unless otherwise noted.(1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Accuracy(1) TA = 25°C –3 3 °C
TA = TMAX –4 4 °C
TA = TMIN –4 4 °C
Nonlinearity(2) TA = TJ = TMIN to TMAX –0.8 0.8 °C
Sensor gain(average slope) TA = TJ = TMIN to TMAX 9.7 10.3 mV/°C
Output resistance TA = TJ = TMIN to TMAX 2000 4000 Ω
Line regulation(3) +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX –1.2 1.2 mV/V
Quiescent current(4) +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX 180 µA
Change of quiescent current +VS = 4.5 V to 10 V, TA = TJ = TMIN to TMAX 2 µA
Temperature coefficient of quiescent current TA = TJ = TMIN to TMAX 2 µA/°C
Long term stability(5) TJ = 125°C, for 1000 hours ±0.08 °C
(1) Accuracy is defined as the error between the output voltage and 10 mv/°C multiplied by the device's case temperature plus 500 mV, at specified conditions of voltage, current, and temperature (expressed in °C).
(2) Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device's rated temperature range.
(3) Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output due to heating effects can be computed by multiplying the internal dissipation by the thermal resistance.
(4) Quiescent current is defined in the circuit of Figure 12.
(5) For best long-term stability, any precision circuit will give best results if the unit is aged at a warm temperature, and/or temperature cycled for at least 46 hours before long-term life test begins. This is especially true when a small (Surface-Mount) part is wave-soldered; allow time for stress relaxation to occur. The majority of the drift occurs in the first 1000 hours at elevated temperatures. The drift after 1000 hours does not continue at the first 1000 hour rate.

6.7 Typical Characteristics

To generate these curves the device was mounted to a printed circuit board as shown in Figure 20.
LM50 LM50-Q1 01203021.png Figure 1. Junction-to-Ambient Thermal Resistance
LM50 LM50-Q1 01203023.png
see Figure 20
Figure 3. Thermal Response in Still Air With Heat Sink
LM50 LM50-Q1 01203025.png Figure 5. Start-Up Voltage vs Temperature
LM50 LM50-Q1 01203027.png
1.
see Figure 12
Figure 7. Quiescent Current vs Temperature
LM50 LM50-Q1 01203029.png Figure 9. Noise Voltage
LM50 LM50-Q1 01203031.png Figure 11. Start-Up Response
LM50 LM50-Q1 01203022.png Figure 2. Thermal Time Constant
LM50 LM50-Q1 01203024.png
Figure 4. Thermal Response in Stirred Oil Bath
With Heat Sink
LM50 LM50-Q1 01203026.png Figure 6. Thermal Response in Still Air Without a Heat Sink
LM50 LM50-Q1 01203028.png
Figure 8. Accuracy vs Temperature
LM50 LM50-Q1 01203030.png Figure 10. Supply Voltage vs Supply Current

7 Detailed Description

7.1 Overview

The LM50 and LM50-Q1 devices are precision integrated-circuit temperature sensors that can sense a –40°C to 125°C temperature range using a single positive supply. The output voltage of the LM50 and LM50-Q1 has a positive temperature slope of 10 mV/°C. A 500-mV offset is included enabling negative temperature sensing when biased by a single supply.

The temperature-sensing element is comprised of a delta-VBE architecture. The temperature-sensing element is then buffered by an amplifier and provided to the VOUT pin. The amplifier has a simple class A output stage with typical 2-kΩ output impedance as shown in the Functional Block Diagram.

7.2 Functional Block Diagram

LM50 LM50-Q1 01203017.png
*R2 ≈ 2k with a typical 1300-ppm/°C drift.

7.3 Feature Description

7.3.1 LM50 and LM50-Q1 Transfer Function

The LM50 and LM50-Q1 follow a simple linear transfer function to achieve the accuracy as listed in the Electrical Characteristics: LM50B table and the Electrical Characteristics: LM50C and LM50-Q1 table.

Use Equation 1 to calculate the value of VO.

Equation 1. VO = 10 mV/°C × T °C + 500 mV

where

  • T is the temperature in °C
  • VO is the LM50 output voltage

7.4 Device Functional Modes

The only functional mode of the device has an analog output directly proportional to temperature.

 
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