Active-Semi Solutions for Sustainability
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Product Features

  • Optimized for Low Voltage Applications
  • 2.6-to-7V Operating Input Range
  • 8V Max Input Blocking Voltage
  • Adjustable In-rush Current Control
  • Configurable Input Power Failure Level
  • 28V@4A Synchronous Buck Supports 100% Duty Cycle
  • Programmable up to 2.25MHz Buck Operating Frequency for Small Inductor Size
  • Power Loss, Vout Power Good, and Storage Cap Power Good Indicators
  • Compatible with Different Types of Storage Caps
    • Super Caps, Electrolytic, Tantalum, POSCAP etc.
  • Autonomous Health Monitoring for Detection of Earlier Storage Capacitor Failures
  • Configurable Interrupts to Inform Host for any Faults/Status Change
  • eFuse, Boost, and Buck UV/OV/OC Protection
  • Thermal Enhanced FCQFN 4×4-32 package


The ACT4921 device is a highly integrated power loss?protection IC that provides autarch capacitor health monitoring for optimized system protection. A built-in boost converter enables high voltage energy storage to minimize the storage capacitor size requirements. The built in buck converter with integrates FETs regulates the storage voltage to the system voltage and also provides hot swap capability and inrush current control.
The ACT4921 is very flexible and can easily be configured and monitored with I2五分快三计划C and external components.

五分快三计划The ACT4921QI-301 is available with the thermal enhanced QFN 4×4 32 pin package.

Orderable Partnumbers

PART NUMBER Input Voltage Storage Voltage Fsw PACKAGE
ACT4921QI301-T 3.3V 28V 1.125MHzkHz FCQFN4x4-32

Advantages of our Power Loss Protection

20m? eFuse Rds(on) at any input voltage Special gate driver circuit design make it suitable for both high voltage and low voltage applications.
High frequency, high efficiency synchronous Buck High backup converter efficiency and current capability, small inductor size.
Autonomous storage cap health monitoring Monitor cap capacitance & ESR and inform host when it’s abnormal, with programmable checking time & threshold.
Blocking FET for short circuit protection Protects system from failure if a storage cap is shorted out

  • Solid State Drive
  • Power Backup Systems
  • Industrial Applications
  • eFuse
  • Hot Plug Devices

ACT4921EVK1-301 Evaluation Tool User’s Guide

This EVK demonstrates the ACT4921QW301 eFuse power management IC.

五分快三计划This document describes the characteristic and operation of the Active Semi ACT4921EVK1QW301 evaluation kit (EVK). It provides setup and operation instructions, schematic, layout, BOM, and test data.

To communicate with the EVK a USB Dongle and a Graphical User Interface (GUI) is provided. Download the?GUI?and all documentation and drivers here or in the Software TAB.

The active-semi? ACT4921 GUI五分快三计划 is a graphical interface that gives the user access to the ACT4921 internal registers. It is specifically designed for use with the ACT4921 EVK.?The GUI allows the user to both read and modify the registers to configure the ACT4921-EVK specifically for the desired operating conditions.

Note that GUI communication with the ACT4921 EVK requires the active-semi??USB-TO-I2C dongle.