A4481: 5 VOUT, 50 mA Automotive Linear Regulator with 50 V Load Dump and Short-to-Battery Protection


The A4481 is a single low-dropout linear regulator with complete control, diagnostics, and protection features that address many requirements of automotive applications. It regulates input voltages from 5.25 to 40 V, down to 5 V ±1% output voltage and is able to supply up to 50 mA of load current.

Diagnostic output from the A4481 includes Power OK (POK) output to alert the microprocessor that a fault has occurred.

Protection features include input undervoltage lockout (UVLO), foldback overcurrent protection, output undervoltage and overvoltage protections (UV/OVP), and thermal shutdown (TSD). In addition, the output is protected from a short-to-battery event up to 32 V.

The A4481 device is available in an 8-pin SOIC package with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte-tin leadframe plating.


Power supplies for:

  • Microcontrollers
  • Transceivers (CAN, LIN, etc.)
  • Sensors

Top Features

  • Automotive AEC-Q100 qualified
  • 5.25 to 40 VIN operating range, 50 V load dump rating
  • 5 V ±1% internal LDO regulator
  • Foldback short-circuit protection
  • Short-to-battery protection (to 32 V, independent of VIN) for harness faults
  • Power OK (POK) flag
  • High-voltage logic level enable input (ENB) for microprocessor control or connection directly to battery
  • Pin-to-pin and pin-to-ground tolerant at every pin
  • Allegro Sensor Bias LDO

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
APEK4481KLJ-01-MH DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Distributor Stock
A4481KLJTR-T 8-lead SOIC -40°C to 150°C Yes View Data Contact your
local sales rep
Distributor 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.

Allegro LJ SOIC with exposed pad 8-pin package


 8-pin SOIC with exposed thermal pad (suffix LJ)