ProjectsPricingInsights

Best Alternatives to MMBT4403

Package: TO-236-3, SC-59, SOT-23-3onsemiTransistors - Bipolar (BJT) - SinglePackage: BulkCurrent - Collector (Ic) (Max): 600 mAVoltage - Collector Emitter Breakdown (Max): 40 VCurrent - Collector Cutoff (Max): 100nADC Current Gain (hFE) (Min) @ Ic, Vce: 100 @ 150mA, 2V

MMBT4403 is an obsolete PNP SOT-23 transistor. Listed alternatives need FAE review because pinout or current ratings are not aligned.

AI replacement insight

Electrical riskhigh

Kept parts derate current.

Package riskmedium

SOT-23 matches, pinout missing.

Firmware risklow

Discrete BJT.

Sourcing riskhigh

Target is obsolete.

Can it be replaced directly?

No vetted pin-compatible replacement is confirmed from these candidates.

Best replacement path

Search for an active PNP SOT-23 BJT rated at least 44 V and 0.6 A.

Main risk

Lower collector current and unverified pinout.

Recommended alternatives

2
BC857B package
BC857B

Good-Ark Semiconductor

Needs validationhigh risk

BC857B is a low-current PNP SOT-23 candidate for MMBT4403 with derating.

View details

Alternative comparison matrix

Feature / factorMMBT4403BC857B2SA812Alt 3Compatibility / risk
PackageSOT-23SOT-23SOT-23SOT-23 — same package; 2SA812: same package
Pinout3 pins3 pins3 pins3 pins — pin functions missing; 2SA812: pin functions missing
Voltage-40 V-45 V-45 V-45 V — meets 1.1x rule; 2SA812: meets 1.1x rule
Current-0.6 A-0.1 A-0.1 A-0.1 A — large derating; 2SA812: large derating
Applicationswitch/amplow-current PNP-low-current PNP — low-load only
LifecycleObsolete--- — status unclear

Application & sourcing insights

Questions & answers

None is confirmed here. A suitable path is an active PNP SOT-23 BJT rated at least 44 V and 0.6 A.