SBVS343 March   2019 TPS7A78

ADVANCE INFORMATION for pre-production products; subject to change without notice.  

  1. Features
  2. Applications
    1.     Typical Schematic
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Active Bridge Control
      2. 7.3.2 Full Bridge (FB) and Half Bridge Configurations
      3. 7.3.3 4 to 1 Switch Capacitor Voltage Reduction
      4. 7.3.4 VLDO_IN Overvoltage Protection
      5. 7.3.5 Dropout Voltage Regulation
      6. 7.3.6 Current Limit
      7. 7.3.7 Programmable Power-Fail Detection
      8. 7.3.8 Power-Good (PG) Detection
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation: AC Input mode
      2. 7.4.2 Dropout Mode
      3. 7.4.3 Disabled Mode
      4. 7.4.4 Normal Operation: DC Input mode
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Recommended Capacitor Types
      2. 8.1.2 Cap-Drop Capacitor CS
      3. 8.1.3 Surge Resistor RS
      4. 8.1.4 Input and Output Capacitors Requirements
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
発注情報

Detailed Design Procedure

For this design example HB configuration is used. the AC Line with cap-drop capacitor and the surge resistor is connected to AC- pin while the Neutral is connected to AC+ pin. The values for CS, RS, CSCIN, R1, and R2 are calculated as follows:

  • CS value is selected from Table 2 to be 220 nF.
  • RS value is calculated using Equation 3 to be 68 Ω.
  • CSCIN value is calculated using Equation 5 to be 35 µF and rounded up to the next standard value of 47 µF.
  • R1 is chosen to be 1 MΩ to minimize divider current from CSCIN while R2 value are calculated using Equation 1 and Equation 2 to be 105 kΩ.
  • CSC1 is chosen to be 1.0 µF.
  • CSC2 is chosen to be 1.0 µF.
  • CLDO_IN is chosen to be 10 µF.
  • CLDO_OUT is chosen to be 1.0 uF.
  • R3 and R4 are chosen to be 100 kΩ each.