AO3400C
Alpha & Omega Semiconductor Inc.
Needs validationhigh risk
AO3400C may fit low-voltage N-MOS switching, with pinout and Vds review.
Best Alternatives to BSS138K
BSS138K is a 60V N-channel SOT-23 MOSFET. Reviewed candidates need pinout and voltage-margin checks before substitution.
AI replacement insight
Electrical riskhigh
lower Vds and higher gate charge
Package riskmedium
SOT-23 matches, pinout missing
Firmware risklow
discrete FET, no firmware
Sourcing riskmedium
one kept option is NRND
Can it be replaced directly?
No verified pin-compatible replacement is proven from the provided data.
Best replacement path
Prefer a 60V N-channel SOT-23 MOSFET with verified G-D-S pinout and similar low Qg/Ciss.
Main risk
Many candidates are 20V or 30V power MOSFETs, not equal 60V small-signal parts.
Recommended alternatives
4Alternative comparison matrix
| Feature / factor | BSS138K | AO3400C | AO3480C | AO3400A | Compatibility / risk |
|---|---|---|---|---|---|
| Package | SOT-23 | SOT-23 | SOT-23 | SOT-23 | SOT-23 — same package; AO3480C: same package; AO3400A: same package; IRLML6244TRPBF: same package |
| Pinout | 3-pin | 3-pin | 3-pin | 3-pin | 3-pin — pin map absent; AO3480C: pin map absent; AO3400A: pin map absent; IRLML6244TRPBF: pin map absent |
| Voltage | 60 V | 30 V | 30 V | 30 V | 30 V / 20 V — fails 60V use; AO3480C: no 60V margin; AO3400A: half rating; IRLML6244TRPBF: major derating |
| Current | 0.4 A | 6.2 A | 6.2 A | 5.7-5.8 A | 6.2 A / 5.7-5.8 A / 6 A — higher Id; AO3480C: higher Id; AO3400A: higher Id; IRLML6244TRPBF: higher Id |
| Application | low Qg 0.65nC | Qg 12nC | Qg 12nC | - | Qg 12nC / power switch — heavier gate; AO3480C: heavier gate; IRLML6244TRPBF: low-ohm FET |
| Lifecycle | Active | - | - | NRND | NRND — sourcing risk |
Application & sourcing insights
Questions & answers
From the provided data, no best direct alternative is verified. Use a 60V N-channel SOT-23 MOSFET with confirmed pinout.