SNVS209G November   2002  – May 2019 LM2733

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit
      2.      Efficiency vs. Load Current
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Switching Frequency
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Pin Operation
  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  Selecting the External Capacitors
        2. 8.2.2.2  Selecting the Output Capacitor
        3. 8.2.2.3  Selecting the Input Capacitor
        4. 8.2.2.4  Feedforward Compensation
        5. 8.2.2.5  Selecting Diodes
        6. 8.2.2.6  Setting the Output Voltage
        7. 8.2.2.7  Switching Frequency
        8. 8.2.2.8  Duty Cycle
        9. 8.2.2.9  Inductance Value
        10. 8.2.2.10 Maximum Switch Current
        11. 8.2.2.11 Calculating Load Current
        12. 8.2.2.12 Design Parameters VSW and ISW
        13. 8.2.2.13 Thermal Considerations
        14. 8.2.2.14 Minimum Inductance
        15. 8.2.2.15 Inductor Suppliers
      3. 8.2.3 Application Curves
  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 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.4 Feedforward Compensation

Although internally compensated, the feedforward capacitor Cf is required for stability (see Figure 24). Adding this capacitor puts a zero in the loop response of the converter. Without it, the regulator loop can oscillate. The recommended frequency for the zero fz is approximately 8 kHz. Cf can be calculated using the formula:

Equation 1. Cf = 1 / (2 X π X R1 X fz)