A4401: Automotive Quasi-Resonant Flyback Control IC

These parts are discontinued. Samples are no longer available. For new customers or new applications, please contact Allegro. Date of status change: December 2, 2014.

This device provides all the necessary control functions to provide the power rails for driving a vacuum fluorescent display (VFD) using minimal external components. The power supply is based on a quasi-resonant, discontinuous flyback converter, operating near the critical conduction boundary. A novel adaptive turn-on control scheme is used to optimize the turn-on and turn-off phase of the MOSFET, to reduce EMI emissions while minimizing switching losses.

The converter is self-oscillating, operating at switching frequencies depending on the input voltage, load, and external components. An onboard linear regulator that is powered directly from the battery provides the housekeeping supply, avoiding the need for complex bias supplies.

Internal diagnostics provide comprehensive protection against overloads, input undervoltage, and overtemperature conditions..

The A4401 is supplied in an 8-pin narrow SOIC package (suffix L), which is lead (Pb) free, with 100% matte-tin leadframe plating.


Astrorep Inc. (Allegro and Sanken Semiconductors, Sanken Power Supplies)
141 John Street, Suite 300
Babylon, NY 11702
Phone: (631)422-2500
Fax: (631)422-2504
Web: www.astrorepinc.com
Email: donna.tweedy@astrorepinc.com

If this is not your local representative, find your local sales rep here.

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  • Multiple output regulator
  • 7 to 40 V input supply
  • Low EMI conducted and radiated emissions
  • Adaptive quasi-resonant turn on/off control
  • Minimal number of external components
  • Enable input which can be driven with respect to the battery voltage

The A4401 is supplied in an 8-pin narrow SOIC package (suffix L), which is lead (Pb) free, with 100% matte-tin leadframe plating.

L-SOIC 8 pin

There are no news items available for this product.

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Product Image Functional Block Diagram

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check
Distributor Stock
A4401KLTR-T 8-lead SOIC -40°C to 125°C Yes View Data Discontinued Contact your
local sales rep
Check Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.

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