A4490EESTR-T

Overview

The A4490EESTR-T is a triple-output step-down switching regulator from Allegro Microsystems, designed for high-current applications. It features an input voltage range of 4.5 V to 34 V and provides three adjustable outputs, each capable of delivering up to 2 A with a voltage range of 0.8 V to 5 V. The device operates at a fixed switching frequency of 550 kHz, enabling the use of small inductors and ceramic capacitors. Multiphase switching interleaves regulator cycles to reduce electromagnetic interference and minimize stress on input capacitors. It includes soft start, power-on-reset functionality, and a charge pump for wide duty cycle operation without clamp circuits.

Feature Summary

• Multiphase switching architecture reduces electromagnetic interference and minimizes stress on input capacitors by interleaving turn-on cycles.
• Integrated charge pump drives power switches to ensure operation at wide operating duty cycles without requiring power-draining clamp circuits.
• Fixed-frequency switching allows selection of small, inexpensive inductors and ceramic output capacitors.
• Includes soft start and power-on-reset (PoR) output features for controlled startup and system protection.

Applications

• Portable electronic devices
• Office automation equipment
• Consumer electronics

Procurement Notes

Verify the specific suffix STR-T indicates tape and reel packaging when ordering. Confirm the QFN-20 package dimensions match your PCB footprint requirements. Check RoHS compliance status if required for your manufacturing process. Ensure input voltage does not exceed 34 V maximum rating during operation.

Selection Notes

Select this component when three independent low-voltage rails are needed from a single higher-voltage source. The 2 A per output capability suits moderate current loads. Consider the 550 kHz frequency for balancing efficiency and component size. Verify thermal performance within the -40°C to +85°C operating range for your enclosure design.

Part Context

This part belongs to the A4490 series of triple-output buck regulators. It replaces older versions like the A4490EES-T, which has been discontinued. The EESTR-T designation specifies the surface-mount QFN package and reel packaging format. It is part of Allegro's PMIC portfolio for integrated power management solutions.

Replacement Considerations

The A4490EES-T is a discontinued direct predecessor. No other active substitutes are listed in official documentation. Verify pin compatibility if considering alternative triple-output regulators from other manufacturers.

FAQ

What is the maximum current per output?

Each of the three outputs can deliver a maximum current of 2 amps.

Does the device include shutdown functionality?

No, the A4490EESTR-T does not have a dedicated shutdown pin; it relies on soft start and power-on-reset features.

What type of package is used?

It uses a 20-WFQFN (Quad Flat Package, No Leads) with an exposed pad, specifically a 4x4 mm QFN-20 package.