UCC24650 200-V Wake-up Monitor for Fast Transient Primary-side Regulation | TI.com

UCC24650 (ACTIVE) 200-V Wake-up Monitor for Fast Transient Primary-side Regulation

 

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 alert signal to a receiving primary-side regulation (PSR) controller. Its low-power consumption helps achieve <5-mW 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 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 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.

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

Parametrics

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Part number Order Frequency (Max) (kHz) UVLO thresholds on/off (V) Features Operating temperature range (C) Package Group Package size: mm2:W x L (PKG)
UCC24650 Order now 83     4.0/3.75V     Chip Enable Gating
Negative Voltage Monitoring    
-40 to 125     SOT-23 | 5     5SOT-23: 5 mm2: 1.6 x 2.9 (SOT-23 | 5)