| Popis: |
Glavni fokus magistrske naloge je offset pri operacijskih ojačevalnikih. Offset ali ''input reffered'' offset je definiran kot napetost, ki jo je potrebno dodati vhodu, da operacijski ojačevalnik na izhodu generira ničti potencial, če sta obe vhodni napetosti na istem potencialu. Obstaja mnogo različnih offsetov. Osredotočil se bom na offset, ki se tvori zaradi elektromagnetnih motenj (''EMI'') in je prisoten v avto-moto industriji. Predstavil bom vzroke za tvorbo offseta z izpeljanim matematičnim modelom, ki bo ravno tako služil za vpogled v odvisnost offseta od različnih parametrov vezja in MOS tranzistorjev. Nato bom model primerjal z meritvami testnega čipa in simuliral offset. Vse to bo potrdilo izpeljan matematični model in omogočilo globlji vpogled v sam pojav offseta. This thesis addresses the problem of offset in operational amplifiers. Offset or input referred offset, is a voltage that has to be added to an input in order for the operational amplifier to produce a zero output level if both inputs are at the same voltage level. There are many types of offset, but I focus on the EMI induced offset which is a problem encountered in EMI polluted environments (automotive industry etc.). I examine the reasons why this offset forms by deriving a mathematical model which will give insight into how various op amp parameters influence offset. I then compare the model to measurement data from produced test chips and also simulate the offset. This provides a deeper understanding of the problem and reinforces the proposed mathematical model. |
