Thaum ua kom nrov lub teeb liab tsis muaj zog, feem ntau yog tsim nyog los txo qis hluav taws xob suab nrov, tshwj xeeb tshaj yog thaum thawj theem ntawm amplification.As dissipative ntsiab, txawm tias zoo tagnrho resistors ib txwm ua suab nrov ntawm lawv cov terminals uas fluctuates cia li. Lub suab nrov Johnson yog qhov tshwm sim los ntawm qhov ntsuas kub hloov ntawm lub resistor, uas yog lub suab nrov yooj yim qhov pib ntawm lub resistor thiab tuaj yeem kwv yees los ntawm nthwv dej dissipation theorem. Siv tus nqi hnyav dua qhov loj dua yuav ua rau lub suab nrov hluav taws xob ntau dua, thaum tus nqi me dua qub yuav ua rau lub suab nrov tam sim no ntawm qhov ntsuas kub.
Lub suab nrov thermal ntawm lub zog tiv tiag yuav ua tau ntau dua li kev kwv yees tau kwv yees, thiab qhov nce siab feem ntau yog zaus tso siab. Lub suab ntau dhau ntawm qhov tseeb resistor tsuas yog pom thaum lub sij hawm tam sim no ntws los ntawm nws.Specifies hauv μV / V / DECADE -μV rau ib volt ntawm cov suab nrov thov rau lub resistor ntawm ib zaus kaum zaus ntau dua. Zaus ntsuas ntsuas hauv dB, yog li ntawd cov resistor nrog lub suab ntsuas qhov ntsuas ntawm 0 dB yuav ua kom pom qhov nrov tshaj li ntawm 1μV (hauv paus txhais tau hais tias square) ib qhov ntsuas hluav taws xob ntawm lub resistor rau txhua kaum tawm xyoo. Yog li, ntau dhau suab nrov yog ib qho piv txwv ntawm 1 / f suab nrov.Film thiab carbon xyaw resistors tsim ntau lub suab ntawm qhov tsawg zaus tshaj li lwm hom kev tiv thaiv, thiab xaim hlau thiab zaj duab xis resistors feem ntau yog siv rau cov yam ntxwv zoo dua. Cov pa roj carbon tivthaiv resistors muaj lub suab nrov ntawm 0dB, thaum cov ntawv ci resistors tej zaum yuav muaj lub suab nrov ntawm -40dB, thiab feem ntau suab nrov ntawm cov ntawv ci resistors tsis tseem ceeb. Nyias-zaj duab xis nto-mount resistors feem ntau muaj suab nrov tsawg dua thiab zoo dua thermal stability dua tuab zaj duab xis nto-mount resistors.
Thermal suab nrov ntawm resistors kuj yog qhov loj-me; feem ntau, raws li lub cev qhov loj me ntawm lub resistor tsub kom (lossis ntau lub resistors raug siv nyob rau hauv parallel), lub suab nrov dua li tsawg dua li kev ywj pheej yoj tsis kam ntawm qhov me me flattens tawm.