AOZ5508QI_2

Overview

The AOZ5508QI is a high-current, high-performance DrMOS power module from Alpha & Omega Semiconductor Inc. It integrates two asymmetrical MOSFETs and an internal driver for synchronous buck applications. The High-Side MOSFET features low capacitance for fast switching, while the Low-Side MOSFET offers ultra-low ON resistance to minimize conduction loss. It operates with a 4.5V to 25V power supply range and supports up to 2MHz switching frequencies.

Feature Summary

• Integrated bootstrap switch and diode emulation mode for improved light-load performance
• Compatible with 5V CMOS logic and Tri-State PWM inputs
• Optimized pin-out layout designed to minimize parasitic effects

Applications

• Memory and graphics cards
• VRMs for motherboards
• Point of load DC/DC converters
• Video gaming consoles

Procurement Notes

Verify the specific suffix QI against the datasheet to confirm the -40°C to +150°C junction temperature range and RoHS compliance. Ensure the ordering code matches the QFN3.5x4.5-22L package configuration. Confirm that the intended application does not involve life support systems, as these are explicitly prohibited by the manufacturer's legal disclaimer.

Selection Notes

Select this component for designs requiring high efficiency in compact form factors. The integrated gate drivers reduce external component count and parasitic loop inductance. Consider the thermal requirements carefully, as the module dissipates significant heat under high-power conditions. Ensure the PCB layout strictly follows the recommended guidelines for VIN and PGND exposed pads to maintain optimal thermal dissipation and switching performance.

Part Context

This device belongs to the DrMOS family, combining power switches and drivers into a single module. It is designed specifically for synchronous buck converters where space and efficiency are critical constraints. The asymmetric MOSFET arrangement allows for optimized performance across varying duty cycles, distinguishing it from standard discrete MOSFET solutions.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation.

FAQ

How is the Diode Emulation Mode activated?

Diode Emulation Mode is activated when the FCCM (Pin 1) input is held Low. In this state, the Low-Side MOSFET enters asynchronous operation during discontinuous conduction.

What is the function of the Tri-State input?

When the PWM input is in a high impedance or Tri-State condition, both High-Side and Low-Side MOSFETs are turned off, placing the VSWH node in a high impedance state.

How is the High-Side gate drive supplied?

The High-Side gate drive is powered by a bootstrap capacitor connected between the BOOT (Pin 4) and PHASE (Pin 5) pins. An internal bootstrap diode eliminates the need for an external diode.