NPN transistor (2N2222A, PN2222, TO-92, 2N2222)
2N2222 · TO-92 · β ≈ 180 · 600 mA
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: 2N2222A / PN2222 (TO-92)
Pins
- E
- B
- C
Ratings and limits
| V_CEO | 40 V |
|---|---|
| I_C | 600 mA |
| P_tot | 625 mW at 25 °C |
| h_FE | 100–300 |
How to use it
Low-side switch for relays, LEDs, buzzers (base resistor sized for I_B ≈ I_C/10), small-signal amplifier, emitter follower.
Lessons and builds that use it
- Common-emitter amplifier
- BJT current gain (β)
- Transistor as a switch
- Emitter follower (buffer)
- Darlington pair
- H-bridge motor driver
- Push-pull output stage
- Astable multivibrator (two transistors)
- Colpitts and Hartley LC oscillators
- Crystal oscillator (Pierce)
- Class A, B and AB output stages
- Cascode amplifier
- Series-pass regulator (transistor + Zener)
- Light-activated switch with relay