anubhavsingh244
Newbie level 5
I am studying microelectronics. I recently got confused about about the small signal models and large signal models. After reading an extensive list of sources, I have come up with some pointers which I want to verify that I have got right.
The term "small signal" can refer two things : small signal amplifier and small signal model/analysis. A small signal model is not the same thing as a small signal amplifier. The same thing can be said about the term "large signal". However both small and large signals are ac signals, and they are large or small with respect to the quiescent or operating point established by the dc bias circuit obtained using DC modeling in both large and small signal amplifier analysis.
Both large and small signal models can be used to model the non linear devices like diodes and transistors( which are operated as amplifiers in active region). The transistor amplifiers are used as voltage or current amplifiers when used as small signal amplifiers and the transistor amplifiers are used as power amplifiers when used as large signal amplifiers.
The small signal amplifier is an amplifier when the applied (AC) input is small with respect to the DC operating point on the DC load line. This type of amplifier uses small signal modeling for its ac analysis. Small signal modeling involved linearizing the non-linear circuit elements at the dc operating point.
There's exist two load lines: dc load line which gives operating point and then there's an ac load line.
The small signal amplifier analysis includes two steps:
1) DC analysis using DC modeling or Large Signal Modeling
2) AC analysis using Small Signal AC (or Incremental) Modeling
The large signal amplifier is used as a power amplifier.
The large signal amplifier analysis includes two steps:
1) DC analysis using DC modeling or Large Signal Modeling
2) AC analysis is done using graphical analysis and no specific model is used here to model the AC operation of large signal.
The DC analysis is done using large signal modeling in both small and large signal amplifiers so it is also called large signal analysis.
The AC analysis done in small signal amplifiers using small signal modeling is small signal analysis.
Please provide feedback if my points are accurate or need improvement.
(I tried searching large signal model of a transistor and also searching dc model of a transistor. The results obtained in images section of google search show the kinds of circuits for dc models and large signal models. That is also how I inferred large signal models and DC models are the same. Some references are also present to support this point).
The term "small signal" can refer two things : small signal amplifier and small signal model/analysis. A small signal model is not the same thing as a small signal amplifier. The same thing can be said about the term "large signal". However both small and large signals are ac signals, and they are large or small with respect to the quiescent or operating point established by the dc bias circuit obtained using DC modeling in both large and small signal amplifier analysis.
Both large and small signal models can be used to model the non linear devices like diodes and transistors( which are operated as amplifiers in active region). The transistor amplifiers are used as voltage or current amplifiers when used as small signal amplifiers and the transistor amplifiers are used as power amplifiers when used as large signal amplifiers.
The small signal amplifier is an amplifier when the applied (AC) input is small with respect to the DC operating point on the DC load line. This type of amplifier uses small signal modeling for its ac analysis. Small signal modeling involved linearizing the non-linear circuit elements at the dc operating point.
There's exist two load lines: dc load line which gives operating point and then there's an ac load line.
The small signal amplifier analysis includes two steps:
1) DC analysis using DC modeling or Large Signal Modeling
2) AC analysis using Small Signal AC (or Incremental) Modeling
The large signal amplifier is used as a power amplifier.
The large signal amplifier analysis includes two steps:
1) DC analysis using DC modeling or Large Signal Modeling
2) AC analysis is done using graphical analysis and no specific model is used here to model the AC operation of large signal.
The DC analysis is done using large signal modeling in both small and large signal amplifiers so it is also called large signal analysis.
The AC analysis done in small signal amplifiers using small signal modeling is small signal analysis.
Please provide feedback if my points are accurate or need improvement.
(I tried searching large signal model of a transistor and also searching dc model of a transistor. The results obtained in images section of google search show the kinds of circuits for dc models and large signal models. That is also how I inferred large signal models and DC models are the same. Some references are also present to support this point).
