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

Description

The TPS7A78 improves the overall efficiency and standby power in power supplies for an easy-to-use non-magnetic approach to AC/DC conversion. The TPS7A78 uses an external capacitor to create a current source and actively clamps the rectified voltage. The device then regulates the voltage down to the application-specific operating voltage. The unique architecture of the device allows the standby power to be reduced from several 100s of milliwatts to just a few 10s of milliwatts. The TPS7A78 takes advantage of an innovative switched capacitor stage to reduce the clamped voltage down by approximately 1/4th of the value, which in turn multiplies the current by 4. Thus, the current source capacitor can be much smaller in size, which minimizes standby power, reduces solution size, and can lead to a lower system cost.

The TPS7A78 is optimized for e-metering applications where the power supply must be reliable and magnetic tamper-proof. The TPS7A78 requires no external magnetics, which makes complying with IEC 61000-4-8 easier while minimizing costly magnetic shielding in e-metering applications.

Additionally, the TPS7A78 also comes with a user-programmable power-fail detection threshold that can provide an early alert to power failures so the system can save data before completely losing power. A power-good indication can also be used for sequencing or to provide a reset to a micro-controller.

The TPS7A78 is available in a 14-pin TSSOP (PWP) package.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TPS7A78 TSSOP (14) 5.00 mm × 6.50 mm
  1. For all available packages, see the order-able addendum at the end of the data sheet.