2N3904 MMBT390 4. MMPQ390 4 PZT3904. NPN General Purpose Amplifier. This device is designed as a general purpose amplif ier and switch. The useful dynamic range extends to 100 mA as a swi tch and to. 100 MHz as an amplifier. Sourced from Process 23.
Low Noise Transistors NPN Silicon MAXIMUM RATINGS Rating Symbol BC549 BC550 Unit Collector–Emitter Voltage VCEO 30 45 Vdc Collector–Base Voltage VCBO 30 50 Vdc Emitter–Base Voltage VEBO 5.0 Vdc Collector Current — Continuous IC 100 mAdc Total Device Dissipation @ TA = 25°C Derate above 25°C PD 625 5.0 mW mW/°C Total Device ... The 2N3904 comes in a TO-92 case with leads in the order C,B,E. Some equivalent transistors have the opposite pinout (E,B,C) and some are B,C,E. This won't be a problem so long as you are aware of the difference, and refer to the datasheet of the part you are using when wiring up the circuit.