A8447: High-Voltage Step-Down Regulator


This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: December 1, 2015.

Recommended Substitutions: For existing customer transition, and for new customers or new applications, refer to the A8498SLDTR-T.

The A8447 is a 3 A, high efficiency general-purpose buck regulator designed for a wide variety of applications. The output voltage is adjustable from 0.8 to 24 V, based on a resistor divider and the 0.8 V 3% reference. External components include an external clamping diode, inductor, and filter capacitor. The offtime is determined by an external resistor to ground. It operates in both continuous and discontinuous modes to maintain light load regulation. An internal blanking circuit is used to filter out transients due to the reverse recovery of the external clamp diode. Typical blanking time is 200 ns.

This device is ideal for various end products including applications with 8 to 50 V input voltage range and require up to 3 A output current, such as uninterruptible power supplies, point of sale (POS) applications, and industrial applications with 24 or 36 V bus.

Applications include:

  • Printer power supplies
  • Office automation equipment
  • POS thermal, laser, photo, and inkjet printers
  • Tape drives
  • Industrial applications

Top Features

  • Wide input voltage range: 8 to 50 V
  • Integrated low RDS(on) DMOS switch
  • 3 A continuous output current
  • Adjustable fixed off-time
  • Highly efficient
  • Adjustable output: 0.8 to 24 V
  • Small package with exposed thermal pad

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A8447SLJTR-T 8-lead SOIC -20°C to 85°C Yes View Data Discontinued 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.


The A8447 is supplied in  8 pin SOIC with exposed thermal pad (suffix LJ). It is lead (Pb) free, with 100% matte-tin leadframe plating.

LJ SOIC with exposed pad 8 pin