SNIS249 May   2025 LM50-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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: LM50-Q1
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 LM50-Q1 Transfer Function
    4. 7.4 Device Functional Modes
  9. 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
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
      3. 8.5.3 Thermal Considerations
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1.      Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
8.2.1.2.1 Capacitive Loads

The LM50-Q1 handles capacitive loading very well. Without any special precautions, the LM50-Q1 can drive any capacitive load. The device has a nominal 2kΩ output impedance (shown in Functional Block Diagram). The temperature coefficient of the output resistors is approximately 1300ppm/°C. Taking into account this temperature coefficient and the initial tolerance of the resistors the output impedance of the device does not exceed 4kΩ. In an extremely noisy environment adding filtering can be necessary to minimize noise pickup. TI recommends adding a 0.1µF capacitor between +VS and GND to bypass the power supply voltage, as shown in Figure 8-3. Adding a capacitor from VO to ground can be necessary. A 1µF output capacitor with the 4kΩ output impedance forms a 40Hz low-pass filter. Since the thermal time constant of the LM50-Q1 is much slower than the 25ms time constant formed by the RC, the overall response time of the device is not significantly affected. For much larger capacitors this additional time lag increases the overall response time of the LM50-Q1.

LM50-Q1 LM50-Q1 No Decoupling Required for Capacitive LoadFigure 8-2 LM50-Q1 No Decoupling Required for Capacitive Load
LM50-Q1 LM50-Q1 With Filter for Noisy EnvironmentFigure 8-3 LM50-Q1 With Filter for Noisy Environment