SNVS710I March   2011  – December 2015 LMZ13608

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application Schematic
      2.      Efficiency 3.3-V Output at 25°C
  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 Output Overvoltage Protection
      2. 7.3.2 Current Limit
      3. 7.3.3 Thermal Protection
      4. 7.3.4 Prebiased Start-Up
    4. 7.4 Device Functional Modes
      1. 7.4.1 Discontinuous Conduction and Continuous Conduction Modes
  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 Design Steps
        2. 8.2.2.2 Enable Divider, RENT, RENB and RENH Selection
        3. 8.2.2.3 Output Voltage Selection
        4. 8.2.2.4 Soft-Start Capacitor Selection
        5. 8.2.2.5 Tracking Supply Divider Option
        6. 8.2.2.6 COUT Selection
        7. 8.2.2.7 CIN Selection
        8. 8.2.2.8 Discontinuous Conduction and Continuous Conduction Modes Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Power Dissipation and Thermal Considerations
    4. 10.4 Power Module SMT Guidelines
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    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
    1. 12.1 Tape and Reel Information

Package Options

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

8.2.2.3 Output Voltage Selection

Output voltage is determined by a divider of two resistors connected between VOUT and AGND. The midpoint of the divider is connected to the FB input.

The regulated output voltage determined by the external divider resistors RFBT and RFBB is:

Equation 4. VOUT = 0.795 V × (1 + RFBT / RFBB)

Rearranging terms; the ratio of the feedback resistors for a desired output voltage is:

Equation 5. RFBT / RFBB = (VOUT / 0.795 V) – 1

These resistors must generally be chosen from values in the range of 1.0 kΩ to 10.0 kΩ.

For VOUT = 0.8 V the FB pin can be connected to the output directly and RFBB can be set to 8.06 kΩ to provide minimum output load.

Table 1 lists the values for RFBT , and RFBB.

Table 1. Typical Application Bill of Materials

REF DES DESCRIPTION CASE SIZE MANUFACTURER MANUFACTURER P/N
U1 SIMPLE SWITCHER PFM-11 Texas Instruments LMZ13608TZ
CIN1,6 (OPT) 0.047 µF, 50 V, X7R 1206 Yageo America CC1206KRX7R9BB473
CIN2,3,4 10 µF, 50 V, X7R 1210 Taiyo Yuden UMK325BJ106MM-T
CIN5 (OPT) CAP, AL, 150 µF, 50 V Radial G Panasonic EEE-FK1H151P
CO1,5 (OPT) 0.047 µF, 50 V, X7R 1206 Yageo America CC1206KRX7R9BB473
CO2 (OPT) 47 µF, 10 V, X7R 1210 Murata GRM32ER61A476KE20L
CO3,4 330 μF, 6.3 V, 0.015 Ω CAPSMT_6_UE Kemet T520D337M006ATE015
RFBT 3.32 kΩ 0805 Panasonic ERJ-6ENF3321V
RFBB 1.07 kΩ 0805 Panasonic ERJ-6ENF1071V
RENT 42.2 kΩ 0805 Panasonic ERJ-6ENF4222V
RENB 12.7 kΩ 0805 Panasonic ERJ-6ENF1272V
CSS 0.47 μF, ±10%, X7R, 16 V 0805 AVX 0805YC474KAT2A
D1 (OPT) 5.1 V, 0.5 W SOD-123 Diodes Inc. MMSZ5231BS-7-F