The 2N4898 is a type of PNP unijunction transistor (UJT). (NOS)

Discover the versatile 2N4898 PNP unijunction transistor (UJT). With a max emitter reverse voltage of 30V and an emitter peak point current of 2 μA, this silicon-based device is perfect for oscillator, timing, and thyristor triggering circuits. Its voltage-controlled negative resistance characteristic makes it ideal for creating simple, low-cost relaxation oscillators and timing circuits. Try it today for sawtooth waveforms and triggering SCRs.

The 2N4898 is a type of PNP unijunction transistor (UJT). It's a silicon-based device used primarily in oscillator, timing, and thyristor triggering circuits.

​Key Specifications

​Type: PNP Unijunction Transistor

​Case Style: TO-92

​Max Emitter Reverse Voltage (V_{EBR}): 30V

​Emitter Peak Point Current (I_P): 2 \muA

​Emitter Valley Point Current (I_V): 4 mA

​Intrinsic Standoff Ratio ($\eta$$): 0.7 to 0.85

​Application

​Unijunction transistors like the 2N4898 are a type of semiconductor that has a single P-N junction. Unlike conventional transistors, they are not used for amplification but rather for their unique voltage-controlled negative resistance characteristic. This makes them ideal for creating simple, low-cost relaxation oscillators and timing circuits. For example, they can be used to generate sawtooth waveforms or to trigger Silicon Controlled Rectifiers (SCRs).