notes:elen90056
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| notes:elen90056 [2021/10/29 05:20] – Updated for end of subject joeleg | notes:elen90056 [2023/05/30 22:32] (current) – external edit 127.0.0.1 | ||
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| For a large signal input, the output can become clipped, becoming linear and flat for part of the signal as the gain cannot be applied. This is when there is no more current available to contribute to the gain. An input difference of $4V_T$ is sufficient to turn one side of the bipolar pair nearly off. This can be used to remove some noise occurring at the peaks of an input signal. | For a large signal input, the output can become clipped, becoming linear and flat for part of the signal as the gain cannot be applied. This is when there is no more current available to contribute to the gain. An input difference of $4V_T$ is sufficient to turn one side of the bipolar pair nearly off. This can be used to remove some noise occurring at the peaks of an input signal. | ||
| - | In a MOS differential pair, there exists a finite differential input voltage to completely switch the current from one transistor to the other, whereas in a bipolar pair that voltage is infinite. For a BJT, the maximum differential input voltage is $|V_{in1}-V_{in2}|_{\max}=4V_T$ (larger than $10mV$ for small signal applications). For a MOS, the maximum differential input voltage is $|V_{in1}-V_{in2}|_\max=\sqrt{2}(V_{GS}-V_{TH})_{equil}$. In MOS, an input difference of the following is considered small. | + | In a MOS differential pair, there exists a finite differential input voltage to completely switch the current from one transistor to the other, whereas in a bipolar pair that voltage is infinite. For a BJT, the maximum differential input voltage is $|V_{in1}-V_{in2}|_{\max}=4V_T$ (larger than $10mV$ for small signal applications). For a MOS, the maximum differential input voltage is $|V_{in1}-V_{in2}|_\max=\sqrt{2}(V_{GS}-V_{TH})_{equil}$. In MOS, an input difference of the following is considered small. $$|V_{in1}-V_{in2}|<< |
| ===== Common Mode Rejection Ratio (CMRR) ===== | ===== Common Mode Rejection Ratio (CMRR) ===== | ||
notes/elen90056.1635484825.txt.gz · Last modified: 2023/05/30 22:32 (external edit)