SNIS177B March   2013  – September 2015 LMT90

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
    6. 6.6 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 LMT90 Transfer Function
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Capacitive Loads
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Community Resources
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7 Detailed Description

7.1 Overview

The LMT90 is a precision integrated-circuit temperature sensor that can sense a −40°C to 125°C temperature range using a single positive supply. The output voltage of the LMT90 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 VO pin. The amplifier has a simple class A output stage with typical 2-kΩ output impedance as shown in the Functional Block Diagram. The output impedance has a temperature coefficient of approximately 1300 ppm/°C. Over temperature the output impedance will max out at 4 kΩ.

7.2 Functional Block Diagram

LMT90 01203017.png
*R2 ≈ 2k With a typical 1300 ppm/°C Drift.

7.3 Feature Description

7.3.1 LMT90 Transfer Function

The LM60 follows a simple linear transfer function in order to achieve the accuracy as listed in Electrical Characteristics:

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

where

  • T is the temperature in °C
  • VOUT is the LMT90 output voltage

7.4 Device Functional Modes

The LMT90's only functional mode is that it has an analog output directly proportional to temperature.