The Infineon MMBT2222ALT1HTSA1 is a general-purpose NPN switching transistor in a SOT-23 surface-mount package. It handles a collector current up to 600 mA with a collector-emitter breakdown voltage of 40 V, and switches at a transition frequency of 300 MHz. Typical applications include low-power switching, driver stages, and signal amplification in industrial controls, consumer electronics, and telecom modules where board space is tight.
The 600 mA collector current rating covers most small-signal switching and driver needs, but it is not a power transistor — the 330 mW power dissipation limit means the junction temperature climbs fast above 150 mA continuous in a SOT-23 at 25°C ambient. For loads over 200 mA, check the thermal derating. The 300 MHz transition frequency is fine for switching up to a few megahertz; for higher-speed logic-level translation, look at a dedicated level shifter. The saturation voltage is 1 V maximum at 50 mA base current and 500 mA collector current — budget that drop when calculating the on-state voltage in a switching circuit.
Last Buy — what it means for procurement
If you have an existing BOM that uses this transistor, now is the time to secure your last order or qualify a pin-compatible replacement. We source it through independent distribution and can quote current availability against an RFQ.