Ib tug bipolar hlws ris transistor (BJT) yog peb -terminal semiconductor ntaus ntawv uas muaj ob PN junctions tsim los ntawm lub emitter, puag, thiab collector cheeb tsam. Raws li PN junction kev npaj, nws tau muab faib ua NPN thiab PNP hom. Tsim nyob rau lub Kaum Ob Hlis 23, 1947, los ntawm Drs. Bardeen, Brighton, thiab Shockley ntawm Tswb Labs, nws lub hauv paus ntsiab lus tseem ceeb yog kom ua tiav kev nthuav dav los ntawm kev tswj hwm qhov kev hloov loj dua hauv cov khoom siv tam sim no los ntawm kev hloov me me hauv lub hauv paus tam sim no. Internal doping concentration sib txawv heev: cheeb tsam emitter yog heev doped, lub hauv paus cheeb tsam yog lub thinnest thiab tsawg doped, thiab lub collector cheeb tsam yog qhov loj tshaj plaws thiab nruab nrab doped.
BJTs ua haujlwm nyob rau hauv peb hom: kev txiav tawm, kev nthuav dav, thiab saturation. Cov tsis tseem ceeb muaj xws li qhov tam sim no amplification factor (hFE), tus yam ntxwv zaus fT, thiab cov collector -emitter breakdown voltage BUCEO. Niaj hnub nimno BJTs feem ntau yog ua los ntawm silicon, thiab cov khoom siv tam sim no tau hloov pauv los ntawm kev tswj lub hauv paus -emitter voltage los hloov cov cab kuj diffusion nyob rau hauv lub emitter junction. Raws li ib qho tseem ceeb ntawm cov hluav taws xob circuits, transistors muaj cov teeb liab amplification thiab hluav taws xob hloov ua haujlwm. Lawv tuaj yeem siv los tsim cov amplifiers los tsav cov neeg hais lus thiab lub cev muaj zog, lossis hloov cov ntsiab lus hauv digital circuits thiab logic tswj. Cov ntawv thov ib txwm muaj xws li qis-frequency/high-frequency power amplification thiab composite transistor designs.
