Device Overview
AO3402 is a 30 V N-channel MOSFET from Alpha & Omega Semiconductor in the SOT-23 package. Its usefulness in low-voltage switching comes from having on-resistance characterized at 10 V, 4.5 V, and 2.5 V gate drive rather than only at a high gate voltage.
Key Selection Information
| Parameter | Verified Information |
|---|---|
| Manufacturer | Alpha & Omega Semiconductor |
| Exact MPN | AO3402 |
| Polarity / configuration | N-channel, single MOSFET |
| Drain-source voltage | 30 V |
| Continuous drain-current headline | 4 A at 25 °C manufacturer parametric condition |
| RDS(on), VGS = 10 V | 52 mΩ maximum at ID = 4 A, Tj = 25 °C |
| RDS(on), VGS = 4.5 V | 65 mΩ maximum at ID = 3 A, Tj = 25 °C |
| RDS(on), VGS = 2.5 V | 85 mΩ maximum at ID = 2 A, Tj = 25 °C |
| Total gate charge | 4.7 nC at 4.5 V gate drive; 10 nC at 10 V gate drive |
| Gate threshold voltage | 0.5 V minimum / 1.0 V typical / 1.5 V maximum |
| Output capacitance | 35 pF |
| Package | SOT-23 |
| Maximum junction temperature | 150 °C |
| Manufacturer status | Full Production |
Engineering Selection Notes
The gate-drive condition changes conduction loss substantially. A design driven from 2.5 V should use the 85 mΩ maximum value at the corresponding 2 A test current, not the 52 mΩ value characterized at 10 V.
Gate threshold is not the recommended drive voltage. The 0.5 V to 1.5 V threshold range only describes the onset of channel conduction at a small test current; low-loss switching requires enough gate voltage to reach the relevant RDS(on) condition.
The 4 A current figure is not a promise that every SOT-23 PCB can carry 4 A continuously. Board copper, ambient temperature, switching loss and junction-temperature rise determine the practical current limit.
Official Engineering Resources
Quality & Verification Support
Third-party inspection or testing can be arranged according to customer requirements. Testing fees are borne by the buyer. Additional verification requirements can be discussed before shipment.
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