SNVSAX6 June   2017 LM78M05-MIL

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 Recommended Operating Conditions
    3. 6.3 Thermal Information
    4. 6.4 Electrical Characteristics
    5. 6.5 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Operation With Low Input Voltage
      3. 7.4.3 Operation in Self Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Voltage
        2. 8.2.2.2 Output Current
        3. 8.2.2.3 Input Capacitor
        4. 8.2.2.4 Output Capacitor
      3. 8.2.3 Application Curves
  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 Documentation Support
      1. 11.1.1 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

7 Detailed Description

7.1 Overview

The LM78M05-MIL device is a fixed positive voltage regulators. It can accept up to 35 V at the input and regulate it down to outputs of 5 V, 12 V, or 15 V. The device is capable of supplying up to 500 mA of output current, although it is important to ensure an adequate amount of heat sinking to avoid exceeding thermal limits. However, in the case of accidental overload the device has built in current limiting, thermal shutdown and safe-operating area protection to prevent damage from occurring.

7.2 Functional Block Diagram

LM78M05-MIL 1048401.png

7.3 Feature Description

The LM78M05-MIL fixed voltage regulator has built-in thermal overload protection which prevents the device from being damaged due to excessive junction temperature.

The regulator also contains internal short-circuit protection which limits the maximum output current, and safe-area protection for the pass transistor which reduces the short-circuit current as the voltage across the pass transistor is increased.

Although the internal power dissipation is automatically limited, the maximum junction temperature of the device must be maintained below 125°C to meet data sheet specifications. An adequate heat sink must be provided to assure this limit is not exceeded under worst-case operating conditions (maximum input voltage and load current) if reliable performance is to be obtained.

7.4 Device Functional Modes

7.4.1 Normal Operation

The device OUTPUT pin sources current necessary to make the voltage at the OUTPUT pin equal to the fixed voltage level of the device.

7.4.2 Operation With Low Input Voltage

The device requires up to 2-V headroom (VIN – VOUT) to operate in regulation. With less headroom, the device may drop out of regulation in which the OUTPUT voltage would equal INPUT voltage minus dropout voltage.

7.4.3 Operation in Self Protection

When an overload occurs, the device shuts down Darlington NPN output stage or reduce the output current to prevent device damage. The device automatically resets from the overload. The output may be reduced or alternate between on and off until the overload is removed.