SNVS129G May   2004  – June 2025 LM2675

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
      1. 5.4.1 Electrical Characteristics – 3.3 V
    5. 5.5  Electrical Characteristics – 5 V
    6. 5.6  Electrical Characteristics – 12 V
    7. 5.7  Electrical Characteristics – Adjustable
    8. 5.8  Electrical Characteristics – All Output Voltage Versions
    9. 5.9  Typical Characteristics
    10. 5.10 Typical Characteristics – Fixed Output Voltage Versions
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Adjustable Output Voltage
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Active Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Fixed Output Voltage Application
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design with WEBENCH® Tools
          2. 7.2.1.2.2 Inductor Selection (L1)
          3. 7.2.1.2.3 Output Capacitor Selection (COUT)
          4. 7.2.1.2.4 Catch Diode Selection (D1)
          5. 7.2.1.2.5 Input Capacitor (CIN)
          6. 7.2.1.2.6 Boost Capacitor (CB)
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Adjustable Output Voltage Application
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 Programming Output Voltage
          2. 7.2.2.2.2 Inductor Selection (L1)
          3. 7.2.2.2.3 Output Capacitor SeIection (COUT)
          4. 7.2.2.2.4 Catch Diode Selection (D1)
          5. 7.2.2.2.5 Input Capacitor (CIN)
          6. 7.2.2.2.6 Boost Capacitor (CB)
        3. 7.2.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 WSON Package Devices
      2. 7.4.2 Layout Examples
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design with WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
7.2.1.2.4 Catch Diode Selection (D1)

In normal operation, the average current of the catch diode is the load current times the catch diode duty cycle, 1-D (D is the switch duty cycle, which is approximately the output voltage divided by the input voltage). The largest value of the catch diode average current occurs at the maximum load current and maximum input voltage (minimum D). For normal operation, the catch diode current rating must be at least 1.3 times greater than the maximum average current. However, if the power supply design must withstand a continuous output short, the diode must have a current rating equal to the maximum current limit of the LM2675. The most stressful condition for this diode is a shorted output condition (see Table 7-4). In this example, a 1-A, 20-V Schottky diode provides the best performance. If the circuit must withstand a continuous shorted output, TI recommends a Schottky diode of higher current.

The reverse voltage rating of the diode must be at least 1.25 times the maximum input voltage. Because of the fast switching speed and low forward voltage drop, Schottky diodes provide the best performance and efficiency. This Schottky diode must be located close to the LM2675 using short leads and short printed circuit traces.

Table 7-4 Schottky Diode Selection Table
VR1-A DIODES3-A DIODES
SURFACE MOUNTTHROUGH HOLESURFACE MOUNTTHROUGH HOLE
20 VSK121N5817SK321N5820
B120SR102—SR302
30 VSK131N5818SK331N5821
B13011DQ0330WQ03F31DQ03
MBRS130SR103——
40 VSK141N5819SK341N5822
B14011DQ0430BQ040MBR340
MBRS140SR10430WQ04F31DQ04
10BQ040—MBRS340SR304
10MQ040—MBRD340—
15MQ040———
50 VSK15MBR150SK35MBR350
B15011DQ0530WQ05F31DQ05
10BQ050SR105—SR305