Product category:
Power Supply ICs and Controllers
News Release from: Allegro MicroSystems Europe | Subject: A4490
Edited by the Electronicstalk Editorial
Team on 16 April 2008
Switching regulator cuts interference
The A4490 uses multiphase switching to reduce electromagnetic interference and minimise stress on the input capacitors by interleaving the turn-on cycle of the regulators.
The A4490 from Allegro MicroSystems Europe is a triple-output stepdown switching regulator integrated circuit that provides three high-current outputs that are adjustable from 0.8 to 5V with a maximum current of 2A Operating from an input voltage range of 4.5 to 34V, the A4490 uses multiphase switching to reduce electromagnetic interference and minimise stress on the input capacitors by interleaving the turn-on cycle of the regulators
This article was originally published on Electronicstalk on 30 Aug 2000 at 8.00am (UK)
Related stories
Integrated switching regulators cut PSU cost
Allegro Sanken now offers a range of integrated high-voltage switching regulators which allow the designer to produce the lowest-cost switch-mode power supply possible
Blue light-emitting diodes available from Allegro
A range of blue light-emitting diodes developed by Sanken Electric is now available from Allegro MicroSystems Europe.
Features like soft start, power-on reset output and a small 4 x 4mm QFN package make the device suitable for many portable, office automation and consumer applications.
The A4490 uses 550kHz fixed frequency switching which allows the selection of small, inexpensive inductors and ceramic output capacitors.
A charge pump is used to provide the supply to drive the power switches to ensure operation at very wide operating duty cycles and to avoid the need for power draining clamp circuits.
A power-on-reset circuit with programmable delay indicates when enabled regulators are in specification.
The power-on reset flag also indicates when the input voltage drops below specification, giving the system controller advance warning while the switching circuits continue to operate down to the shutdown level.
Internal diagnostics provide comprehensive protection against overloads, input undervoltages and overtemperature effects.
The Allegro A4490 is supplied in a low-profile 0.75mm, 4 x 4mm, 20-pin QFN package with exposed power tab.
• Allegro MicroSystems Europe: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
