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Best Alternatives to MMBT3904T

Package: SC-89, SOT-490onsemiTransistors - Bipolar (BJT) - SinglePackage: Tape & Reel (TR); Cut Tape (CT); Digi-Reel®Current - Collector (Ic) (Max): 200 mAVoltage - Collector Emitter Breakdown (Max): 40 VDC Current Gain (hFE) (Min) @ Ic, Vce: 100 @ 10mA, 1VFrequency - Transition: 300MHz

MMBT3904T is an obsolete NPN SOT-523 BJT. Candidate replacements need pinout and rating review before use.

AI replacement insight

Electrical riskmedium

Check V/I/P/fT margins.

Package riskhigh

Pinout not verified.

Firmware risklow

Discrete BJT; no firmware.

Sourcing riskmedium

Target is obsolete.

Can it be replaced directly?

No verified pin-compatible replacement is proven by the provided fields.

Best replacement path

Start with MMBT2222AT for function, then verify SOT-523 pinout and VCEO margin.

Main risk

Pinout evidence is missing, and some candidates require electrical derating.

Recommended alternatives

1
2SC4617 package
2SC4617

onsemi

Needs validationmedium risk

2SC4617 may work in derated NPN SOT-523 circuits.

View details

Alternative comparison matrix

Feature / factorMMBT3904TMMBT2222AT2SC4617Alt 3Compatibility / risk
PackageSOT-523SOT-523; ES also SC-89SOT-523SOT-523; ES also SC-89 — conflicting evidence; 2SC4617: package string matches
Pinout3 pinspin count missing3 pinspin count missing / 3 pins — pinout not proven; 2SC4617: pin functions missing
Voltage40 V VCEO40 V VCEO50 V VCEO40 V VCEO / 50 V VCEO — no 1.1x margin; 2SC4617: meets margin
Current200 mA600 mA150 mA600 mA / 150 mA — higher IC; 2SC4617: derate load
ApplicationNPN GP switchNPN GP switch180 MHz NPNNPN GP switch / 180 MHz NPN — same role; 2SC4617: slower fT

Application & sourcing insights

Questions & answers

MMBT2222AT is the strongest functional candidate here, but it still needs pinout and package verification.