AON6922 Equivalent & Substitute Parts

Part Overview

The AON6922 is a dual N-channel MOSFET array in an 8-DFN surface mount package, rated for 25V drain-to-source voltage with continuous drain currents of 18A and 31A. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement continuity. Substitute parts must maintain compatibility across electrical ratings, package form factor, and thermal characteristics to ensure direct replacement capability in existing applications.

Substiute Parts

AON6922

Alpha & Omega Semiconductor Inc.In Stock: 13387AON6922 Datasheet

Current PartRFQ

AON6992

Alpha & Omega Semiconductor Inc.In Stock: 15658AON6992 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AON6922 is determined by the following critical electrical and mechanical parameters:

Voltage Rating Compatibility: The substitute part must support the application's maximum drain-to-source voltage requirement. The AON6922 operates at 25V Vdss; substitute parts with equal or higher voltage ratings (30V or greater) are acceptable for direct replacement in circuits designed for 25V operation.

Current Handling Capability: Continuous drain current ratings must meet or exceed the application requirement. The AON6922 provides 18A and 31A; substitute parts with equivalent or superior current ratings ensure thermal and electrical performance parity.

On-Resistance (Rds On): This parameter directly affects power dissipation and switching efficiency. The AON6922 specifies 3.8mOhm at 20A and 10V gate voltage. Substitute parts with comparable or lower on-resistance values maintain or improve circuit efficiency.

Gate Charge and Input Capacitance: These parameters influence switching speed and gate drive requirements. Lower gate charge and input capacitance values reduce switching losses and simplify driver design.

Package and Mounting: The AON6922 uses an 8-DFN surface mount package with exposed pad. Substitute parts must use identical or mechanically compatible package geometries to ensure PCB layout compatibility.

Configuration: The dual asymmetrical N-channel configuration must be preserved in substitute parts to maintain circuit functionality.

The AON6992 meets these substitution criteria with a higher voltage rating (30V), comparable current ratings (19A, 31A), and compatible package specifications.

Parameter Comparison

Engineering Selection Recommendations

AON6992 as Primary Substitute: The AON6992 is the manufacturer-recommended substitute for the AON6922. Both components share identical operating temperature ranges (-55°C to 150°C), dual asymmetrical N-channel configuration, and surface mount 8-DFN package geometry. The AON6992 provides a higher voltage rating (30V versus 25V), enabling operation in applications with higher transient voltage margins. The AON6992 demonstrates superior switching characteristics with significantly lower gate charge (13nC versus 32nC) and input capacitance (820pF versus 2340pF), resulting in reduced switching losses and simplified gate drive requirements.

Compliance Considerations: The AON6992 carries ROHS3 compliance certification, whereas the AON6922 compliance status is not specified. Both parts maintain REACH Unaffected status and identical moisture sensitivity levels (MSL 1). For applications requiring documented RoHS compliance, the AON6992 provides explicit certification.

On-Resistance Trade-off: The AON6992 exhibits higher on-resistance (5.2mOhm versus 3.8mOhm at 20A, 10V), resulting in increased conduction losses. This parameter difference must be evaluated against the application's thermal budget and efficiency requirements. The AON6992's higher maximum power dissipation rating (3.1W versus 2W/2.2W) partially compensates for this characteristic.

Gate Threshold Voltage: The AON6992 specifies a higher gate threshold voltage (2.2V versus 1.7V), requiring verification that existing gate drive circuits provide sufficient overdrive voltage for reliable switching operation.

Frequently Asked Questions (FAQ)

Q: Can the AON6992 directly replace the AON6922 in existing PCB designs?

A: The AON6992 is mechanically compatible with the AON6922 in 8-DFN surface mount packages. However, electrical parameter differences—specifically higher on-resistance, higher gate threshold voltage, and different input capacitance—require circuit validation. Gate drive voltage and thermal management must be re-evaluated for the specific application.

Q: What is the significance of the higher Vdss rating (30V) on the AON6992?

A: The 30V rating on the AON6992 provides additional voltage margin compared to the 25V AON6922. In applications operating at or near 25V, the AON6992 offers improved reliability against transient overvoltage events. This does not alter the component's suitability for 25V nominal operation.

Q: How do the gate charge differences affect circuit performance?

A: The AON6992's lower gate charge (13nC versus 32nC) reduces the charge that must be supplied by the gate driver to switch the MOSFET. This results in faster switching transitions, reduced switching losses, and lower gate driver power consumption. Existing gate drive circuits designed for the AON6922 will operate the AON6992 with improved efficiency.

Q: Are there package compatibility concerns between 8-WDFN and 8-PowerWDFN?

A: Both packages are 8-pin DFN variants with 5x6mm footprints and exposed pads. The designations reflect internal die and thermal management differences rather than external package dimensions. PCB layouts designed for the AON6922 (8-WDFN) are compatible with the AON6992 (8-PowerWDFN) without modification.

Q: What thermal considerations apply when substituting the AON6992?

A: The AON6992's higher on-resistance generates increased conduction losses compared to the AON6922. The higher maximum power dissipation rating (3.1W) accommodates this characteristic. Thermal analysis must confirm that PCB copper area, thermal vias, and ambient conditions provide adequate heat dissipation for the application's duty cycle.

Q: Is the AON6992 suitable for logic-level gate drive applications?

A: Both the AON6922 and AON6992 feature logic-level gate capability. However, the AON6992's higher gate threshold voltage (2.2V) requires verification that the gate drive voltage exceeds this threshold by a sufficient margin to ensure reliable on-state operation. Standard 3.3V or 5V logic outputs are compatible with both devices.

Q: What is the impact of lower input capacitance on the AON6992?

A: The AON6992's significantly lower input capacitance (820pF versus 2340pF) reduces the capacitive load on the gate driver. This permits faster switching transitions, reduces gate driver current requirements, and improves overall circuit efficiency. Existing gate drive circuits will experience improved performance characteristics.