SNIS194 December   2016 LM73-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 Temperature-to-Digital Converter Characteristics
    6. 6.6 Logic Electrical Characteristics- Digital DC Characteristics
    7. 6.7 SMBus Digital Switching Characteristics
    8. 6.8 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 Power-On Reset
      2. 7.3.2 One-Shot Conversion
      3. 7.3.3 Temperature Data Format
      4. 7.3.4 SMBus Interface
      5. 7.3.5 ALERT Function
      6. 7.3.6 Communicating With the LM73-Q1
        1. 7.3.6.1 Reading from the LM73-Q1
        2. 7.3.6.2 Writing to the LM73-Q1
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
    5. 7.5 Register Map
      1. 7.5.1 LM73-Q1 Registers
        1. 7.5.1.1 Pointer Register
        2. 7.5.1.2 Temperature Data Register
        3. 7.5.1.3 Configuration Register
        4. 7.5.1.4 THIGH Upper-Limit Register
        5. 7.5.1.5 TLOW Lower-Limit Register
        6. 7.5.1.6 Control/Status Register
        7. 7.5.1.7 Identification Register
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Thermal Path Considerations
      2. 8.1.2 Output Considerations: Tight Accuracy, Resolution and Low Noise
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Related Documentation
    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

Package Options

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

1 Features

  • Qualified for Automotive Applications
  • AEC-Q100 Qualified With the Following Results
    • LM73-Q1 Temperature grade 1: –40°C to 125°C
    • LM73-Q1 HBM ESD Classification Level 2
    • LM73-Q1 CDM ESD Classification Level C6
  • Single Address Pin Offers Choice of Three Selectable Addresses Per Version for a Total of Six Possible Addresses.
  • SMBus and I2C-compatible Two-Wire Interface
  • Supports 400-kHz Operation
  • Shutdown Mode With One-shot Feature Available for Very Low Average Power Consumption
  • Programmable Digital Temperature Resolution From 11 Bits to 14 Bits
  • Fast Conversion Rate Ideal for Quick Power Up and Measuring Rapidly Changing Temperature
  • Open-Drain ALERT Output Pin Goes Active When Temperature is Above a Programmed Temperature Limit
  • Very Stable, Low-noise Digital Output
  • UL Recognized Component
  • Temperature Accuracy: ±1.45°C (Maximum)
  • Temperature Range: –40°C to 125°C
  • Conversion Time
    • 11-Bit (0.25°C): 14 ms (Maximum)
    • 14-Bit (0.03125°C): 112 ms (Maximum)
  • Operating Supply Current: 320 µA (Typical)
  • Shutdown Supply Current: 1.9 µA (Typical)
  • Resolution: 0.25°C to 0.03125°C

2 Applications

  • Automotive Climate Control
  • Advanced Driver Assistance Systems (ADAS)
  • Airflow Sensor
  • Infotainment Processor Management
  • Instrument Cluster Control
  • UREA Sensors
  • HID Lamps

3 Description

The LM73-Q1 is a digital output temperature sensor featuring an integrated incremental Delta-Sigma ADC. The LM73-Q1 communicates with a two-wire interface that is compatible with SMBus and I2C interfaces, and the host can query the LM73-Q1 at any time to read temperature.

The LM73-Q1 operates over a wide temperature range (–40°C to 125°C) and provides ±1.45°C accuracy from –10°C to 80°C. The LM73-Q1 includes four selectable resolution options that allow the temperature conversion time and sensitivity to be adjusted for optimal performance. The LM73-Q1 defaults to 11-bit mode (0.25°C/LSB), and will measure temperature in a maximum time of 14 ms, making it ideal for applications that require temperature data very soon after power-up. In its 14-bit maximum resolution mode (0.03125°C/LSB), the LM73-Q1 is optimized to sense very small changes in temperature.

A single multi-level address line selects one of three unique device addresses. An open-drain ALERT output goes active when the temperature exceeds a programmable limit. Both the data and clock lines are filtered for excellent noise tolerance and reliable communication. Additionally, the LM73-Q1 has a time-out feature that will automatically reset the clock and data lines, if these lines are held low for an extended period of time. This prevents a bus lock-up condition without requiring host processor intervention.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM73-Q1 SOT (6) 2.90 mm × 1.60 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

LM73-Q1 20147803.gif

4 Revision History

DATE REVISION NOTES
December 2016 * Initial release.