SNVS686K March   2011  – May 2024 LMZ22005

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
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Synchronization Input
      2. 6.3.2 Output Overvoltage Protection
      3. 6.3.3 Current Limit
      4. 6.3.4 Thermal Protection
      5. 6.3.5 Prebiased Start-Up
    4. 6.4 Device Functional Modes
      1. 6.4.1 Discontinuous And Continuous Conduction Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Design Steps
        2. 7.2.2.2 Enable Divider, RENT, RENB and RENH Selection
        3. 7.2.2.3 Output Voltage Selection
        4. 7.2.2.4 Soft-start Capacitor Selection
        5. 7.2.2.5 Tracking Supply Divider Option
        6. 7.2.2.6 CO Selection
        7. 7.2.2.7 CIN Selection
        8. 7.2.2.8 Discontinuous And Continuous Conduction Modes Selection
      3. 7.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Examples
    3. 9.3 Power Dissipation and Thermal Considerations
    4. 9.4 Power Module SMT Guidelines
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.2.2.3 Output Voltage Selection

Output voltage is determined by a divider of two resistors connected between VO and ground. 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. VO = 0.8 V × (1 + RFBT / RFBB)

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

Equation 5. RFBT / RFBB = (VO / 0.796 V) – 1

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

For VO = 0.8 V the FB pin can be connected to the output directly and RFBB can be omitted.

Table 7-1 lists the values for RFBT , and RFBB.

Table 7-1 Typical Application Bill of Materials
REF DESDESCRIPTIONCASE SIZEMANUFACTURERMANUFACTURER P/N
U1SIMPLE SWITCHERPFM-7Texas InstrumentsLMZ22005TZ
Cin1,50.047 µF, 50 V, X7R1206Yageo AmericaCC1206KRX7R9BB473
Cin2,310 µF, 50 V, X7R1210Taiyo YudenUMK325BJ106MM-T
Cin6 (OPT)CAP, AL, 150 µF, 50 VRadial GPanasonicEEE-FK1H151P
CO1,60.047 µF, 50 V, X7R1206Yageo AmericaCC1206KRX7R9BB473
CO2 (OPT)100 µF, 6.3 V, X7R1210TDKC3225X5R0J107M
CO5220 μF, 6.3 V, SP-Cap(7343)PanasonicEEF-UE0J221LR
RFBT3.32 kΩ0805PanasonicERJ-6ENF3321V
RFBB1.07 kΩ0805PanasonicERJ-6ENF1071V
RSN (OPT)1.50 kΩ0805Vishay DaleCRCW08051K50FKEA
RENT42.2 kΩ0805PanasonicERJ-6ENF4222V
RENB12.7 kΩ0805PanasonicERJ-6ENF1272V
RFRA(OPT)23.7Ω0805Vishay DaleCRCW080523R7FKEA
RENH100 Ω0805Vishay DaleCRCW0805100RFKEA
CFF180 pF, ±10%, C0G, 50 V0805TDK08055A181JAT2A
CSS047 μF, ±10%, X7R, 16 V0805AVX0805YC474KAT2A
D1(OPT)5.1 V, 0.5 WSOD-123Diodes Inc.MMSZ5231BS-7-F