SLUSBL6 February   2015 UCC24650

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 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 UVLO Block
      2. 7.3.2 PCD
      3. 7.3.3 Sample, Hold, and Transient Detector
      4. 7.3.4 Wake Pulse Generator and WAKE Switch
      5. 7.3.5 PCD Counter and ENS Switch
    4. 7.4 Device Functional 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
      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 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Enables Excellent Load Transient Performance and Zero Standby Power
  • Enables Smallest Output Capacitor for Tight ΔVOUT
  • No External Components Required
  • <50 µA Device Current Consumption (Typical)
  • 5-V to 28-V Output Monitoring Capability
  • 3% Voltage Droop Detection (Patent Pending)
  • 200-V Wake-Up Switch
  • Enables and Disables SR Controller, Relay Control, or Other Secondary Circuits
  • SOT-23 5-Pin Package

2 Applications

  • <5-mW Zero-Power Standby Applications
  • Adapters and Chargers for Consumer Electronics
    • Smart Phones, Tablets, Set-Top Box
  • TV and Monitor Power Supplies
  • Home Appliance SMPS
    • Refrigerator, Washing Machine, Air Conditioners
  • Industrial Power Supplies for Lighting and Home Automation

3 Description

The UCC24650 is an easy-to-use secondary-side voltage monitor that periodically measures its own VDD voltage. A relative droop of 3% from the previous reading triggers a wake-up alert signal to a receiving primary-side regulation (PSR) controller. Its low-power consumption helps achieve <5-mW Zero-Power standby loss in many applications.

An internal 200-V MOSFET switch is applied across a ground-referenced rectifier to provide a current-limited pulse to the flyback transformer secondary winding, which couples the signal to the primary-side controller. This signal is repeated at 33 kHz until controller-driven switching activity is detected.

Relative-droop detection allows scaling to any voltage between 5 and 28 V. The wake-up alert function allows very-low standby frequency to minimize switching loss and reduction of output capacitance needed to respond to a heavy load step. This monitor is used with a controller capable of detecting the wake-up signal, such as the UCC28730 PSR flyback controller.

The UCC24650 also provides an enable and disable signal which can be used to control a secondary-side circuit during no-load conditions to reduce standby power loss. Such a circuit may be a synchronous rectifier controller or a relay driver, for example.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UCC24650 SOT-23 (5) 2.92 mm × 1.30 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Schematic

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Rapid Full-Load Step Response

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