2N2646

The 2N2646 is a unijunction transistor (UJT) manufactured by Solid State Devices Inc (SSDI). It is designed for use in timing, oscillator, and trigger circuits where a negative resistance characteristic is required. Key electrical specifications include a maximum interbase voltage of 35 V, a typical valley current of 5 µA, and a maximum power dissipation of 300 mW. The device is packaged in a TO-206AA / TO-18-3 metal can, which supports through-hole mounting. The 2N2646 is listed as RoHS3 compliant and REACH unaffected, though these compliance statuses are unverified. As a unijunction transistor, it is commonly employed in relaxation oscillators, pulse generators, and phase control applications. The TO-18 package provides robust mechanical protection and reliable thermal performance for the 300 mW power dissipation.