SNIS118G July   1999  – January 2017 LM50 , LM50-Q1

PRODUCTION DATA.  

  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

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DBZ|3
Thermal pad, mechanical data (Package|Pins)

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.